{"1": {"fulltext": "", "height": "3369", "width": "2246", "jp2-path": "outlinesofplantl00barn_0001.jp2"}, "2": {"fulltext": "", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0002.jp2"}, "3": {"fulltext": "", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0003.jp2"}, "4": {"fulltext": "", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0004.jp2"}, "5": {"fulltext": "OUTLINES OF PLANT LIFE\\nWITH SPECIAL REFERENCE TO FORM\\nAND FUNCTION\\nCHARLES REID BARNES\\nProfessor of Plant Physiology in the University of Chicago\\nNEW YORK\\nHENRY HOLT AND COMPANY\\n1900", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0005.jp2"}, "6": {"fulltext": "TWO COPIES RECEIVED,\\nLibrary of Congtat*\\nOffice Qf the\\nMAR I 1900\\nKeglstsr of Copyrights\\n55819\\nCopyright, igoo,\\nBY\\nHENRY HOLT CO.\\nSfcUONU COPY,\\nROBERT DRUMMOND, PRINTER, NEW YORK.", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0006.jp2"}, "7": {"fulltext": "OUTLINES OF PLANT LIFE.\\nPART I: THE PLANT BODY.\\nCHAPTER I.\\nINTRODUCTION.\\n1. Living matter. By the combination of powers called\\nlife, each living thing controls, for a longer or shorter time,\\na certain amount of material, which constitutes its body.\\nThis material is arranged into definite form some remains\\nonly for a short time as part of the body and is then discarded;\\nother material remains part of the body as long as life exists.\\nThat which is changing most rapidly is the living substance,\\ncalled protoplasm. If there are parts of the body not living,\\nthey have been formed by the protoplasm and are generally\\ncontrolled by it.\\n2. Members. When the body is large, it is easy to see\\nthat it is made up of more or less distinct parts. These are its\\nmembers. As a rule, the smaller it is, the fewer and less dis-\\ntinct are the members. There are many thousands of plants\\nin which the body does not have any members, but can be\\ndistinguished only into the units of which it is built, called\\ncells. Still others consist of a single cell.\\nIn the largest plants the more important members may be\\ndivisible into smaller subordinate ones. When these are in-", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0007.jp2"}, "8": {"fulltext": "2 OUTLINES OF PLANT LIFE.\\nspected they too are seen to be made up of a great many\\nminute parts, each consisting of a bit of living protoplasm\\nand some other things which it has made. These parts are\\ncalled cells. (See 4.)\\nThus, a corn plant has two principal members, a root, below ground,\\nand a shoot above ground. The root consists of many subordinate mem-\\nbers, the roots and the rootlets; the shoot consists of stem and leaves\\nthe leaves of sheath and blade, etc. But a duckweed shoot has no dis-\\ntinction of stem and leaf, and only a single root. The pond scums have\\nno members, but consist of a row of cells; while in many diatoms the\\nbody is a single cell.\\n3. Reproduction. Every plant must provide for its own\\nexistence. To do this, it must possess means for securing, or\\nfor making, and using food. During this feeding period its\\nmost striking characteristic is growth. It must also provide\\nbefore it dies for the production of new plants of the same\\nkind. When the plant is very simple, both duties must be\\ndone by the same cell, but in more complex plants special\\ncells, and in many cases special members, are provided for\\nreproduction. The two processes are sometimes carried on\\nat the same time, but more commonly reproduction occurs at\\nsome particular or limited period.\\nIt is convenient to consider first the form of the plant body\\nand those members which are not concerned in reproduction.\\nParts I and II therefore, treat of the work and parts of the\\nplant which promote its own life and growth, i.e. the vegeta-\\ntive body. Part III discusses the form and action of the re-\\nproductive parts, so far as these can be studied without a\\nmicroscope.\\n4. The cell. A plant-cell is a minute portion of living\\nmatter, called protoplasm, generally surrounded by a mem-\\nbrane, called the cell-wall (fig. 1).\\nThe protoplasm is the essential part of the cell. It con-\\nstructs the cell-wall. Rarely, if ever, is it uniform through-", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0008.jp2"}, "9": {"fulltext": "INTAOD UCTION.\\nout, but shows distinct parts, each having special work to do.\\nIn the most complete and active cells the greater part of the\\nprotoplasm consists of a finely granu-\\nlar or nearly transparent, colorless\\nportion, in which the other parts\\nseem embedded.\\nProtoplasm is not a single sub-\\nstance, but a mixture of several dif-\\nferent substances, so intimately\\nmixed and so easily destroyed that\\nit is not possible to analyze it. More-\\nover, the nature and amount of the\\ncomponents are probably variable.\\nIn all but the youngest cells there are\\none or more bubbles of water in the\\nprotoplasm.\\n5. Nucleus. The nucleus is one\\nof the most important parts of the\\ncell. It is generally spherical or ovoid, but in long cells it\\nmay become elongated (fig. 2, z). The nucleus may divide\\ninto two, and this is commonly followed by the formation\\nof a partition-wall separating the cell into two parts, each con-\\ntaining one of the daughter-nuclei.\\n6. Plastids. In most cells there are also other parts,\\ncalled plastids. In young cells these are small, rounded,\\ncolorless bodies. As the cell grows older they increase in\\nsize and number. When mature and in cells which lie near\\nthe surface of green plants, they are commonly roundish or\\nbiscuit-shaped, of spongy texture, and colored yelllowish-\\ngreen by a substance known as chlorophyll These are con-\\nsequently known as chloroplasts or chlorophyll-bodies (fig.\\n2). In other cells, particularly those for the storage of food,\\nthey may develop into smaller, denser, flattened or roundish,\\nuncolored bodies, whose work is usually to gather starch into\\nFig. i.\u00e2\u0080\u0094 A cell (the meajaspore)\\nfrom a lily ovule, filled with\\ngranular protoplasm, in which\\nis embedded a large spherical\\nnucleus, containing a nucle-\\nolus, and accompanied by two\\ncentrospheres, a. The line\\naround the protoplasm repre-\\nsents the cell-wall, with those\\nof the adjacent cells connected.\\nMagnified 500 diam. After\\nGuignard.", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0009.jp2"}, "10": {"fulltext": "4 OUTLINES OF PLANT LIFE.\\ngrains (fig. 3). In other cells, particularly in highly colored\\nparts, the plastids may become of most diverse form and\\nsize, and take on a red or yellow\\ncolor (fig. 4).\\n7. Wall. The cell-wall is\\nFig. 2. Fir.. 3.\\nFig. 2. A cell from the interior of the leaf of the oat, showing its wall, and some\\ninclusions of the protoplasm. 2, the nucleus c chloroplasts o, an oil-drop. Mag-\\nnified about 1000 diam. After Zimmermann.\\nFig. 3. Part of the cell contents of an inner cell of white potato, z, nucleus s, starch\\ngrains, each having been formed by a leucoplast, which is still attached to one side\\nof the grain crystalloid. Magnified about 1000 diam.\u00e2\u0080\u0094 After Zimmermann.\\nformed by the protoplasm. In green plants when first\\nformed it consists chiefly of cellulose, with which, as it grows\\nolder, various other substances may be mixed. Some of these\\nb c\\nFig. 4. A, chromoplasts from flower leaves of an orchid B, from the root of carrot\\nC, from the fruit of mountain-ash. Embedded in the protoplasmic body of the\\nchromoplast are sometimes proteid crystalloids, pigment-crystals, f, or starch-\\ngrains, s. Magnified about 1000 diam After Schimper.\\nare present even in the young wall, and may increase with\\nage others are characteristic of special changes which the\\nwall may undergo.", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0010.jp2"}, "11": {"fulltext": "IN TROD UCriON.\\n8. Growth of the cell-wall. As the cells become older\\nthe wall may increase in thickness. It must also increase in\\narea as the cells grow in size. The growth in area is usually\\naccomplished by putting new particles between the older\\nones. Growth in thickness is rarely uniform. Pits or pores\\nare formed in the wall when it thickens except at these spots.\\nWhen the thin parts are large and only certain spots or lines\\ngrow thicker, the wall shows projecting spikes, bands, or\\nthreads.", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0011.jp2"}, "12": {"fulltext": "CHAPTER II.\\nSINGLE-CELLED PLANTS AND COLONIES.\\nIn the lakes and pools, in ditches and slow streams, on\\nthe surface of damp rocks and wood, may be found many\\nsorts of microscopic plants, whose entire body is merely a\\nsingle cell.\\n9. Fission-algae. The simplest forms of the single-celled\\ngreen water plants are the fission -algae. In the central part\\nof the cell is the nucleus, and the whole of the protoplasm is\\ncolored by the yellowish-green dye, chlorophyll. Along\\nwith it, there is a blue coloring matter, so that in mass these\\nalgae look bluish-green or even black-\\nish. For this reason they are called\\nblue-green algae to distinguish them\\nfrom those in which only the yellow-\\ngreen color is present.\\n10. Gelatinous colonies. The cell-\\nwall may be thin, but commonly it is\\ncomposed of several layers, of which\\nthe outer are changed into mucilage.\\nThis swells into a transparent jelly when\\nwet, either becoming alike throughout\\nor showing distinct layers. When a\\nnumber of such forms grow in company (fig. 5), this jelly-like\\nmaterial blends into a single mass in which the associated\\nplants seem to be embedded.\\n6\\nFig\\nA blue-green alga\\n{GIa?oca/ s i). Single indi-\\nviduals, A, and colonies\\n(B-E) of various ages.\\nMagnified 300 diam. After\\nSachs.", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0012.jp2"}, "13": {"fulltext": "SINGLE-CELLED PLANTS AND COLONIES.\\n11. Gelatinous filament-colonies. In other cases, instead\\nof being held together only by the weak jelly-like portion of\\nthe cell-wall, the plants, still practically independent the one\\nof the other, remain connected by the firmer portions of the\\nwall into rows, forming irregularly coiled or serpentine fila-\\nments, which are embedded in a profuse jelly (fig. 6). The\\nFig. 6. Nostoc. A, a gelatinous colony, irregularly lobed. Natural size. a por-\\ntion of a serpentine filament with five heterocysts (one at each end by which it was\\nseparated from the rest of the cells composing the filament, and three intermediate\\nones) and the jelly belonging to it. Magnified about 400 diam. After Thuret and\\nJanczewski.\\nreal independence of the cells, even though they remain con-\\nnected, is shown by the fact that such a chain may be broken\\nup into any number of pieces and each piece will retain all\\nits powers. Here and there in the chain there occur cells\\nunlike the rest, whose purpose seems to be to break the chain\\ninto pieces, which work their way out of the jelly and grow\\ninto independent colonies. The association of considerable\\nnumbers of these plants in colonies gives rise to masses of jelly\\nwhich vary from the size of a pin -head to 2-5 centimeters in\\ndiameter. They may be found adhering to water-weeds as\\nclear- or dirty-green masses, or sometimes floating free\\n(A, fig. 6).\\nEXERCISE I.\\nNostoc or Kivularia. I. Observe the size and form of the colonies\\nand the consistence of the jelly enclosing them. (|n.)", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0013.jp2"}, "14": {"fulltext": "8\\nOUTLINES OF PLANT LIFE.\\n2. Crush a bit of a Nostoc colony or a whole one of Rivularia between\\ntwo glass slips, remove the upper slip, cover with water and observe the\\ncoiled (Nostoc) or radiating straight filaments (Rivularia) embedded in\\nthe jelly. (Fig. 6.)\\n12. Filaments of loose organization. Of very near kin\\nto these plants are the oscillarias, which have received this\\nname from the pendulum-like swinging\\nof their tips (fig. 7). In them the cell-\\nwalls remain connected more extensively\\nand more firmly, so that each cell is\\ndisk-shaped, and the filament is much\\nless easily separated into its parts.\\nMoreover less of the wall has become\\njelly-like, so that often this part is not\\napparent and is difficult to see even when\\nthe plants are looked at with the micro-\\nscope. Even though invisible, it may\\nFig. 7. r-Oscillaria. a, the r J\\ntip; b, a portion of the be detected by the slippery feel of the\\nmiddle of a filament. Mag-\\nnified 540 diam. After plants when rubbed gently between the\\nStrasburger.\\nfingers.\\nEXERCISE II.\\nOscillaria. 1. Observe the color of a bit of Oscillaria. 9.)\\n2. With needles tease out the specimen in a drop of water on a glass\\nslip; observe the delicate thread-like form. (Fig. 7.)\\n3. Transfer a bit of living Oscillaria to a small glass dish or white in-\\ndividual butter plate with a little water; protect it from drying up with\\na cover; 24 hours later observe the position of the filaments. 12.)\\n4. Demonstration. Dip a considerable mass of Oscillaria in hot water\\nfor a moment and put in a white butter plate with as small a quantity of\\nwater as will cover it. As the water evaporates observe the color depos-\\nited on the dish at the edge of the water. 9.)\\n13. Feeding habits. The feeding habits of the oscillarias\\nare worth notice. These plants are found in permanent pud-\\ndles and ditches where organic matter is decaying. The sig-", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0014.jp2"}, "15": {"fulltext": "SINGLE-CELLED PLANTS AND COLONIES. 9\\nnificance of this is that some of the ancestors of the green\\noscillarias probably had offspring which, instead of living\\nupon food prepared by means of the green coloring matter\\n185 ff.), learned to use the organic matter in the water,\\nat first perhaps no more than the present oscillarias do but\\ngradually they came to live exclusively upon it. As a conse-\\nquence, they lost their green color and became incapable of\\nexisting where organic food cannot be had.\\nBacteria.\\n14. Fission-fungi. Along with the loss of color and change\\nof habit went a diminution in size. They have now become\\nso different that they are known as fission-fungi, and popu-\\nlarly as bacteria, bacilli, microbes, germs, etc. These plants,\\nprobably the descendants of common ancestors with the fis-\\nsion-algae, are the smallest known living things (figs. 8, 9).\\nThe diameter of many sorts does not exceed .0005 of a milli-\\nmeter. That would allow 1 75 to lie side by side upon the edge\\nof the paper on which this book is printed. Though so minute\\nthese plants have the same sort of protoplasm and cell -wall as\\nlarger ones. They increase in number rapidly by each cell\\ndividing into two, which separate readily into independent\\nplants.\\n15. Gelatin. In the fission-fungi, as in the fission-algae,\\nconsiderable masses of jelly-like material are produced, in\\nwhich the plants may lie embedded. The films, sometimes\\nsmooth, sometimes wrinkled, which appear on an infusion of\\norganic matter, such as tea or broth, are formed by masses\\nof bacteria which rise to the surface and become embedded in\\nthe gelatinous material they produce (3, fig. 8).\\nDemonstration. Steep a cupful of chopped hay in hot water for fifteen\\nminutes, and set the infusion, loosely covered, in a warm place. After a\\nday or two, show the film of bacteria which covers the surface of the\\nliquid.", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0015.jp2"}, "16": {"fulltext": "10\\nOUTLINES OF PLANT LIFE.\\n16. Cilia. Most species are furnished with organs of\\nmovement consisting of fine threads of protoplasm protruded\\nFig. 8. Various bacteria, a, Micrococcus, the blood-portent b, zooglcea form\\nof the same; c, Bacterium aceti, the ferment of vinegar; d, Sarcina, a harmless\\nparasite of the human intestine, a, b, magnified 300 diam.; c, 2000 diam.; d, 800\\ndiam.\u00e2\u0080\u0094 After Kerner.\\nr\\nFig. 9.\u00e2\u0080\u0094 Bacteria stained to show cilia. A, cilia tufted at one end; B, cilia irregularly\\ndistributed over body C, cilium single at one or both ends. B, the bacillus of typhoid\\nfever; C, the bacillus of Asiatic cholera. Magnified 775 diam. After Migula.\\nthrough the wall. These, by their sudden contraction on one\\nside, lash about like whips, and propel the cell by jerky,\\ndarting motions through the fluid in which it swims, These", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0016.jp2"}, "17": {"fulltext": "SINGLE-CELLED PLANTS AND COLONIES. II\\nlashes, called cilia, may be single at the ends of the cell (C,\\nfig. 9), or many at ends or sides (A, fig. 9), or the whole cell\\nmay be covered with them like hairs (B, fig. 9). They may\\nbe withdrawn or drop off when the plant comes to rest, as\\nwhen they form the scums previously mentioned.\\nThese plants are most interesting on account of their rela-\\ntion to health and disease, decay, fermentation, etc., which\\ncannot be discussed here.*\\n17. Yellow-green algae. Among the single-celled green\\nplants, one of the most common groups is that represented\\nby fig. 10, which shows one of a large series, in which the\\nbody consists of a single cell with its wall, protoplasm,\\nnucleus, and a few relatively large chloroplasts. In this\\ngreater specialization of the protoplasm, these plants show\\nthe only advance upon the blue-green algae. The wall in\\nsuch as this Pleurococcus is almost uniform and quite thin.\\nThe cells of some kinds are frequently associated in colonies,\\nembedded in jelly or not.\\nEXERCISE III.\\nPleurococcus. I. Examine with a lens pieces of bark bearing Pleuro-\\ncoccus and similar algse. Note the irregular distribution of the green\\ngranular heaps of plants. Is there any similarity to the distribution of\\nhigher plants over uncultivated areas\\n2. After soaking a piece of bark for a few minutes, scrape off with\\nthe nail or a dull knife blade some of the green material, spread it as\\nwell as possible in a drop of water on a slip of glass, cover it with a\\npiece of thin glass, avoiding air-bubbles, and examine with a lens.\\nObserve the minuteness of some of the specks, which are mostly single\\nplants The larger ones are clusters of plants.\\n3. Dejnonstration. Show a slide under microscope and have pupils\\nFor further information on these plants, see Frankland Our Secret\\nFriends and Foes Prudden Story of the Bacteria, Dust and its Dan-\\ngers. Drinking-water and Ice Supplies Russell: Dairy Bacteriology;\\nFrankel (tr. by Linsley): Bacteriology (medical).", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0017.jp2"}, "18": {"fulltext": "12\\nOUl^LINES OF PLANT LIFE,\\nobserve the form and color of single plants, many consisting of two or\\nmore cells still joined together, resulting from cell division. 17, fig. 10.)\\nFig. 10. Pleurococcus viridis. A a single individual B, a colony shortly after\\ndivision C, the same after separation. Magnified 540 diam. After Strasburger.\\nFlG. 11. Various diatoms, a, Synedra b, Pleurosigma c, d, Grammatofihora,\\nside and top views e, colony of Govifihonema, with branched stalks attached to an\\nalga f, g, single cells of same, more magnified, top and side views; /z, colony of\\nDiatoma, the cells connected into a zigzag band k, colony and individuals (top and\\nside views) of Fragillaria I, w, n, Coccovema. In m the pair is surrounded by\\njelly preliminary to the escape of the protoplasm and the formation of two new cells\\n(auxospores) which has been completed in n.\u00e2\u0080\u0094 After Kerner.\\n18. Shelled plants. Other one-celled plants constitute a\\ngroup known as diatoms, found in both fresh and salt waters,\\neither attached or free-swimming (figs. 11, 12). The dia-", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0018.jp2"}, "19": {"fulltext": "S1XGLE-CELLED PLANTS AND COLONIES.\\n3\\ntoms are very various in form, and present two different\\naspects. When seen from the side they are generally elon-\\ngated-rectangular. When looked at from above they are\\nshort-cylindric, disk-shaped, boat-shaped, or variously curved\\nor angular. They are peculiar in having the cell-wall so\\nfilled with silica that scarcely any other material is left. In-\\ndeed the plants may be heated to a red heat and boiled in\\nacid without destroying the form and markings of the cell-\\nwall, so completely has it become silicified. To permit\\ngrowth this rigid cell- wall is constructed in two pieces which\\nfit together like the two parts of a pill-box (fig. 12). Each\\nFig. t2.\u00e2\u0080\u0094 A single diatom (Navicula amphirhynchus). A, top view; B, side view,\\nshowing overlapping of the valves. The parts shaded by lines are the chloroplasts\\nthe dotted part the protoplasm, with nucleus about the center of cell. Magnified\\n750 diam. After Pfitzer.\\nof these pieces, or valves, is sculptured into regular patterns\\nin lines and dots, which are often so excessively minute or\\nclose together as to be barely visible with the highest powers\\nof the microscope (b, fig. 11). Seen in mass, as they may\\noften be on the sides of a glass aquarium, living diatoms ap-\\npear yellowish-brown. The chloroplasts, which are some-\\ntimes single and always few, have a brownish color in addi-\\ntion to the green chlorophyll.\\nIt is not uncommon for the diatoms to form colonies by\\nthe adhesion of several or many individuals by means of\\ngelatinous cell-walls. These colonies are ribbon-like, or zig-", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0019.jp2"}, "20": {"fulltext": "14\\nOUTLINES OF PLANT LIFE.\\nzag chains, or even branched filaments {h, i, fig. n).\\nOther sorts may be attached singly or in clusters by a gelati-\\nnous stalk (e, fig. n). In all cases the jelly, like the rest\\nof the cell-wall, is a product of the protoplasm. The slow-\\ngliding movements of some free diatoms are due to the pro-\\ntrusion of strands of protoplasm through slits in the valves.\\nFig. 13. Various desmids. a, Micrasterias b, Cosmarium c, Xanthidium\\nd, Ciosterium e, Staurastrum f, Aptogonum. Magnified about 200 diam.\\nAfter Kerner.\\n19. The desmids. These form another group of one-\\ncelled green algae. They have neither the brownish color\\nnor siliceous wall characteristic of diatoms, but are bright\\ngreen cells of remarkably diverse and often beautiful forms.\\nAs a rule the cell is flattened and is divided almost into two\\nby a deep constriction near the middle (a, b, c, e, fig. 13).\\nOften the body of the cell is covered with warts or spine-like", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0020.jp2"}, "21": {"fulltext": "SINGLE-CELLED PLANTS AND COLONIES. 1$\\nprojections c, fig. 13), or is prolonged into horn-like or\\nhair-like lobes. These plants also frequently cohere into\\ncolonies fig. 13). In that case tooth-like projections of\\nthe cell-wall may interlock.\\n20. Summary. The simplest plants consist of a single\\ncell, which is often protected by a copious mucilage. By\\nthis means also the plants are often associated in colonies of\\nvarious forms. Among the green plants some possess in\\naddition a blue coloring matter others a brown. Many\\ncan move about from place to place. The bacteria are de-\\ngenerate relatives of the blue-green algae which have lost their\\ngreen color, and thus their power to make their own food.", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0021.jp2"}, "22": {"fulltext": "CHAPTER III.\\nFILAMENTOUS ALG^E.\\nObviously some of the plants mentioned in the last chap-\\nter, such as the oscillarias, are colonies of cells well on the\\nway to complete union into co-\\nherent filaments whose elements\\nare attached to each other by con-\\nsiderable areas of the cell-wall.\\nIn order clearly to understand this\\ncondition, we must consider the mode\\nof origin of the individual cells composing\\nthe row.\\n21. Fission. Under conditions mostly\\nunknown to us, in the course of its growth\\na cell may divide by a process known\\nas fission. The material of the nucleus\\npasses through a complex series of\\nchanges and separates into two parts.\\nIn a plane between these daughter-nuclei particles are deposited to form\\na cell-wall (A, fig. 14). In this way a single one-celled plant of Plenro-\\nFig. 14. A, one of the final stages\\nin cell-division. The daughter-\\nnuclei are still connected by fila-\\nments, and across the equatorial\\nplane particles of new cell-wall\\nmaterial are formed Z the com-\\npletion of cell division the\\ndaughter-nuclei have rounded off\\nand the new wall is like the\\nlateral walls. Magnified 880 diam.\\nAfter Strasburger.\\nFig. 15 Diagrams of cell-division\\nspherical cells, a, b, by the wall 1\\nA, division of a spherical cell into two hemi-\\nB, the same after further division in planes 2,\\n2, 3, parallel to 1. a has divided by wall 2 into a and another cell which has again\\ndivided by wall 3 into a a b has divided into b b\\\\ the inner of which has\\nelongated preparatory to a division into b b as by wall 3. C, fig. A, after a second\\ndivision, by wall 2, at right angles to 1.\\n16", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0022.jp2"}, "23": {"fulltext": "FILAMENTOUS ALGyE.\\ncoccus [A, fig. io) may divide\\ninto tAvo, so that it consists of\\ntwo hemispherical cells, each\\ncapable of independent growth\\n(fig. 23, A).\\nIn the filamentous algoe the\\ncells formed by such divisions\\nremain connected throughout\\ntheir whole extent, and as the\\nsuccessive divisions are parallel\\na cell row results fig. 15).\\nWhen the divisions are in two\\nplanes the cells form a flat sheet\\n(c, fig. 15); and when in three\\nplanes, a mass.\\n22. Filamentous algae.\\nThere is a large number\\nof plants in which the vege-\\ntative body throughout life\\nhas the form of a filament.\\nThe green plants of this\\nsort live almost entirely in\\nwater or in wet places, and\\nmay be conveniently desig-\\nnated as filamentous algce.\\n23. Pond scums.\\nAmong these none are\\nmore beautiful or interest-\\ning than the pond scums,\\nrepresented in our waters\\nby several genera (Spiro*\\ngyra, Zygnema, Mougeotia\\nand some others They\\nTo the same group also\\nbelong the single-celled desmids\\nalready described.\\nFig. 16. Fig. 18.\\nFig. 16. A cell from filament of Spirogyra.\\nch, chloroplast (there are three in this cell)\\npyrenoids k, nucleus. Magnified 200 diam.\\nAfter Strasburger.\\nFig 17. Two cells from filament of Zygnema,\\nshowing the gelatinous sheath greatly swollen,\\nand stellate chloroplasts, in which is a pyrenoid,\\nwith the nucleus in a strand of protoplasm\\nbetween them. Magnified 245 diam.\u00e2\u0080\u0094 After\\nKlebs.\\nFig. 18.\u00e2\u0080\u0094 A cell from filament of Mougeotia.\\nThe darker body nearly filling cell is the chloro-\\nplast (face view) in which are pyrenoids, and\\ntannin vesicles, g. If seen from a direction at\\nright angles it would appear as a narrow stripe\\nin the center of the cell, z, the nucleus. Mag-\\nnified about 200 diam. After Zimmermann.", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0023.jp2"}, "24": {"fulltext": "1 8 OUTLINES OF PLANT LIFE.\\nmay be readily recognized, during their vegetative period,\\nby their unbranched filaments, bright green color, and slippery\\nfeel between the fingers.*\\nUnder the microscope, they are at once distinguished from other filamen-\\ntous algae by the shape of their chloroplasts. In Spirogyra these form one\\nor more flattish, spirally wound ribbons, notched on the edges, and em-\\nbedded in the protoplasm near the cell-wall (ch, fig. 16). In Zygnema\\nthere are generally two irregularly star-shaped chloroplasts (fig. 17) while\\nin Mougeotia a single flat, plate-like chloroplast, nearly as wide as the cell,\\ntraverses its center (fig. 18). See also fig. 19.\\nEmbedded in the chloroplasts of these and other algae are usually seen\\none or more angular, colorless bodies, often surrounded by a jacket of\\nstarch. These are stores of reserve food, known as pyrenoids (J figs.\\n16, 18).\\nIn these plants there is little or no difference between the\\nparts of the filaments. If broken into two, each part may\\ncontinue growing with no damage to any part except the cells\\nwhich were ruptured in severing the plant.\\nEXERCISE IV.\\nSpirogyra. If fresh material is available examine a few filaments in a\\nwhite dish for color. If preserved material is used, stain red by immers-\\ning for a few minutes in eosin (cheap red ink will answer).\\nExamine with a lens. Observe\\n1. Length whether broken or whole whether with or without\\nbranches.\\n2. The delicate partitions, like white lines, crossing the green (or red)\\nfilaments, dividing the protoplasm of one cell from another. Can the\\nform of the chloroplasts be seen (Cf. fig. 16.) This can be readily seen\\nonly in the larger species. 23.)\\n3. Demonstration. Mount a few fresh filaments in water. Show under\\nmoderate power the form of the chloroplasts the reserve food nodules\\nthe nucleus. (Fig. 16.)\\nThis slipperiness is due to the gelatinous outer part of the cell-wall\\n(fig. 26), which is only visible after special treatment or on examining\\nthe filaments in a thin mechanical solution of Chinese ink.", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0024.jp2"}, "25": {"fulltext": "FILA MEN TO US. A L GAZ.\\n19\\n24. Base and apex. But other filamentous algae show a\\ndistinction between base and apex. In Ulothrix (fig. 19)\\nthe basal cell is elongated and pointed, and\\nis colorless, because it is not furnished with\\nchloroplasts like the others. By this pointed\\ncell the plant is loosely attached, at least when\\nyoung, to the substratum, while the green por-\\ntion waves freely in the water. Thus arises a\\ndistinction into two parts, viz., the rhizoid and\\nthe thallus.\\nIn Cladophora, Vaucheria, and their allies,\\nthe plants are generally attached by a well-\\ndeveloped rhizoid region, which is often\\nbranched (w, fig. 20), as is also the thallus.\\nIn contrast with the preceding, therefore,\\nlocalization of growth, producing branching,\\nmay be observed.\\n25. Branching. A branch begins by the\\ngrowth in area of a limited portion of the cell-\\nwall. Since growing cells are usually stretched\\nby the water they absorb, the pressure upon\\nthe enlarged region causes the wall to bulge out-\\nward there. The convexity gradually increases\\nas the region grows, until the swelling becomes\\nan outgrowth whose further lengthening consti-\\ntutes a branch similar to the main filament.\\nGrowth in length may be limited to the tip of\\na filament, or to a narrow zone including one or more cells,\\nor it may occur indifferently in any cell, or in all cells.\\nFig. 19. Ulo-\\nthrix zonata.\\nA young fila-\\nment with rhi-\\nzoid cell, r, at\\nbase. Magnified\\n482 diam. Af-\\nter Dodel-Port.\\nEXERCISE V.\\nCladophora. If fresh material is at hand observe in a white dish\\npreserved specimens are used stain for a few minutes in eosin.\\n1. How is the plant attached", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0025.jp2"}, "26": {"fulltext": "20\\nOUTLINES OF PLANT LIFE.\\n2. Observe form and particularly the abundant branching. Can a\\nsingle main axis be traced How many branches arise at one point\\nFig. 20. A young plant of Vaucheria, developing from the spore. A, mature spore\\nB, the same after germination has begun C, plant further developed from spore, sp,\\nwith growing apex, s, and rhizoid, iu, by which it attaches itself to the mud. The\\nchloroplasts are numerous and close together next the wall on all sides. Magnified 28\\ndiam.\u00e2\u0080\u0094 After Sachs.\\n26. Partition walls unnecessary. Many algae, while ex-\\nternally like others, which are divided into true cells, have not\\nthe units of structure separated by cell-walls. In Vaucheria,\\nfor example, the whole of the vegetative body forms a single\\nchamber, in which lies the undivided protoplasm, corre-\\nsponding to many cells, as shown by the numerous nuclei\\nwhich are distributed through it. The external walls of the\\ncells are formed, but the partition walls are not formed.\\n27. External segmentation. A plant body of this con-\\nstruction may attain considerable size and complexity, as in\\nCaulerpa (fig. 21),* even to mimicking, upon a small scale,\\nthe form of leafy plants. In such cases the external walls\\nbecome considerably thickened, and across the chamber, from\\none side to the other, run irregular bars of similar material\\nwhich act as braces to prevent the collapse of the outer walls\\n(fig. 22).\\nIn Caulerpa, particularly, a high degree of development as\\nto external form is reached (fig. 21). There is a stem-like\\nNote carefully the scale of the figures.", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0026.jp2"}, "27": {"fulltext": "FILAMENTOUS ALGM.\\n21\\naxis, v-s, creeping in the mud, which bears green leaf-like\\nbranches, b, on one side and clusters of colorless root-like\\nFig. 21. Part of a plant of Caulerf a. See text, IF 27. Two-thirds natural size.\\nAfter Sachs.\\nbranches, w, on the other. Not only are a base (posterior\\nend) and an apex (anterior end) distinguishable, but the\\nplant shows a difference between an\\nupper (dorsal) and under (ventral) side,\\nthe leaf-like thallus lobes arising from\\nthe dorsal side, while rhizoids spring\\nfrom the ventral side.\\n28. The thallus.\u00e2\u0080\u0094 To the loose ag-\\ngregation of single cells into colonies of\\nFig. 22.- Transverse section\\ndefinite form, as well as to the body of axis of Cauier/ a, show-\\ning cross-bars to stiffen wall.\\nformed by their more intimate union in Magnified about 25 diam.\u00e2\u0080\u0094\\nnil After Murray.\\nthe cell rows and masses just described,\\nthe name thallus is applied. The term is most frequently\\napplied to those more complicated forms which constitute\\nthe vegetative bodies of the higher algae, which are now\\nto be described.\\n29. Summary. Instead of being loosely associated in e\u00c2\u00a9l-", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0027.jp2"}, "28": {"fulltext": "22 OUTLINES OF PLANT LIFE.\\nonies, plant cells may remain firmly united in rows or sheets.\\nSuch an aggregation of cells is then called a plant. The\\nform of the plant depends upon the mode of division of the\\ncells. The body may be thread-like, and alike at both ends.\\nOr it may be distinguishable into a base and apex, or even\\ninto a root-like part, the rhizoid, and a shoot-like part, the\\nthallus. Either may branch. Branching is due to more\\nrapid local growth of certain regions. In some plants the\\nprotoplasm is not, or only incompletely, divided by cell-\\nwalls.", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0028.jp2"}, "29": {"fulltext": "CHAPTER IV.\\nTHE THALLUS OF THE HIGHER ALG^E.\\n30. The larger algae. From the thread-form algae,\\nwhose body is a single row of cells, it is but a step to those\\nforms whose body consists of a single sheet of cells. One\\ncommon form has a leaf-like body, which grows attached to\\nstones or other algae. The broader forms are sometimes\\n20-25 cm. wide.\\nThe body of the sea-lettuce is somewhat similar in structure,\\nbut consists of two layers of cells,\\nand, as fig. 23 shows, is very clearly\\ndistinguishable into an organ of\\nattachment, the rhizoid, and the leaf-\\nlike part for which the name thallus\\nmay be kept.\\nSo, from the thread-like bodies we\\npass through sheet-like to massive\\nbodies of a broadly extended form.\\nLikewise there may be found all in-\\ntermediate forms between the thread-\\nlike algae and those whose bodies\\nare slender, but are more than one\\nrow of cells thick.\\nFig. 23.\u00e2\u0080\u0094 A small plant of Ulva\\nlactuca, the sea-lettuce, show-\\ning thallus, and rhizoid for\\nattaching it to rocks. Natural\\nsize.\u00e2\u0080\u0094 From\\nIn other marine algge a still higher specialization of members is reached.\\nOne of the red seaweeds may be used to show the gradual advance in\\ncomplexity.\\n23", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0029.jp2"}, "30": {"fulltext": "24\\nOUTLINES OF PLANT LIFE.\\nPolysiphonia.\\n31. External form. The body of Polysiphonia, a slender\\nalga (fig. 24) which grows in abundance upon rocky sea-\\ncoasts, is much branched. The main axis is\\nmade up in its larger parts of five or more rows\\nof cells, the central row being surrounded by a\\njacket of at least four others (fig. 25) but at\\nthe tips even of the main axis there is only\\na single row of cells, as in the simplest algae\\n(fig. 26). The body of Polysiphonia, there-\\nFig 24. Fig. 25. Fig 26.\\nFig. 24.\u00e2\u0080\u0094 An entire plant of Polysiphonia, showing mode of branching. Natural size.\\nAfter Kiitzing.\\nFig. 25. Transverse section of one of the branches of rolysif-honia, showing a\\nminute central cell with four large and four small cells surrounding it. Magnified\\nabout 50 diam. From a drawing by Mr. Grant Smith.\\nFig. 26. Apex of a branch of Polysiphonia which has nearly ceased growing. Mag-\\nnified about 100 diam. From a drawing by Miss Rowan.\\nfore, is one of the simplest forms composed of cells massed\\ntogether.\\n32. Growth. Growth in length can take place only at the\\nends of the main axis and its branches, because there each\\napical cell (fig. 26) produces, by division near its base, the\\nnew cells whose later division and enlargement make the\\nmature axes.\\n33. Color. In this plant, as in very many of the marine\\nalgae, there is present, in addition to the green of the chloro-\\nplasts, a special red coloring matter. To the naked eye, this", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0030.jp2"}, "31": {"fulltext": "THE THALLUS OF THE HIGHER ALG/E. 2$\\ncolor overpowers the green and gives the plant a pink tinge.\\nIn other red algre it is often present in greater quantity and\\nvariety of hue, so that brilliant reds and purples, with shadings\\nof brown and green, mark the more striking species.\\nEXERCISE VI.\\nPolysiphonia. Place a plant in a glass dish over a black or white back-\\nground. Observe\\ni. The form of the body and the mode of branching. (Fig. 24.)\\n2. The mode of attachment at the base, if specimens are entire.\\n3. Demonstration. Mount the tip of one of the branches and show the\\nhigh, dome-shaped, apical cell, with segments cut off successively from its\\nbase, to be later themselves divided longitudinally. 32, fig. 26.)\\n4. Cut a transverse section of a medium-sized axis and observe the four\\nlarge peripheral cells, surrounding a central cell the latter to be seen only\\nunder compound microscope. 31, fig. 25.)\\nBetween the very simple body of Polysiphonia and the much\\nlarger and more complex body of the common bladder- wrack,\\nor Fucus vesiculosus, there are all gradations, which cannot\\nbe described here.\\nFucus.\\n34. External form. The body of Fucus (fig. 27) is large\\nas compared with the plants previously described. It is often\\n75-100 cm. long by 1-2 cm. broad, of greenish- brown color\\nand somewhat leathery texture. Near the base the thallus is\\ncontracted into a stalk whose extremity is broadened into a\\nsucker-like disk (often irregularly branched) which attaches\\nthe plant firmly to the wave-washed rocks, on which it grows.\\nAbove, the thallus is flattened, with a thicker rib in the mid-\\ndle (fig. 28), and branches abundantly by forking. These\\nbranches, though often twisted, really lie in the same plane\\nas the flattening (fig. 27). Here and there the thallus has", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0031.jp2"}, "32": {"fulltext": "26 OUTLINES OF PLANT LIFE.\\npairs of oval bladdery swellings, which, by the gases they con-\\ntain, give greater buoyancy to the plants in the water.\\nFig. 27. Upper part of a plant of Fucus vesicu.osus. r, midrib of thallus\\nbladders s, swollen tips covered by numerous elevations, in each of which is a pit\\nwhich contains many sex-organs. Two thirds natural size.\u00e2\u0080\u0094 After Luerssen.\\n35. Growing point. The very tip of each growing branch\\nis notched and at the bottom of the notch is a group of cells\\nwhich by division produce all the parts of the thallus. This", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0032.jp2"}, "33": {"fulltext": "THE THALLUS OF THE HIGHER ALG^E. 2J\\nyoungest region, found also at the tips of the growing axes of\\nthe higher plants, is the growing point. It has no limit below,\\nbut as the parts further and further from the apex are exam-\\nined, they are seen to become more and more unlike with age\\nuntil the mature form is reached.\\n36. Mature thallus. If the mature part of the thallus be\\ncut at right angles and a thin slice be cut off one end, placed\\non a glass slip and examined with a lens, it shows two distinct\\nregions a central one, quite translucent, the pith, bounded\\nby an outer brownish opaque region, the cortex. The\\ncentral part is very full of mucilage, produced by a change\\nin the substance of the cell-walls of the pith region. In the\\nbladders this mucilaginous pith does not increase to fill the\\ncentral space, but this is occupied by a great chamber filled\\nwith air and other gases. In the midrib the structure is\\nplainly denser than elsewhere, except in the stalk below,\\nwhich is like an enlarged midrib without the side wings.\\n37. Division of labor. Complete examination of other\\nparts, the attachment disk, the hair pits (fig. 28) with which\\n:.v \u00e2\u0096\u00a0:_\u00e2\u0096\u00a0\u00e2\u0096\u00a0 \u00e2\u0096\u00a0_. a\\nFig. 28. A transverse section of the thallus of Fucus, showing midrib, r\\\\ cortex, c\\\\\\npith, m and a hair pit, p. Magnified 10 diam.\u00e2\u0080\u0094 From a drawing by Mr. C. E. Alien.\\nmany species are covered, etc., would reveal still other ways\\nin which unlikeness arises with age from the uniformity of the\\ngrowing point. With the change of form there is always di-\\nvision of labor, which we can interpret only in a very imper-\\nfect fashion from our own standpoint. The compact cortex\\nis nutritive and probably in part protective the bladders serve\\nto increase the buoyancy of the plants when the tide is in\\nwhile the abundant mucilage, found in the interior, probably\\nserves to retain the moisture when the plants are exposed by", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0033.jp2"}, "34": {"fulltext": "28 OUTLINES OF PLANT LIFE.\\nthe ebbing tide the hair pits are useless, so far as known\\nand the strong, elastic disk and stalk above hold the plants in\\nplace as they sway constantly back and forth in every wave\\nof the rising or falling tide.\\n38. Color. The coloring matter in Fucusand other brown\\nseaweeds is of two kinds, a green (chlorophyll), and a brown.\\nThese colors are found chiefly in the cortex, which is, there-\\nfore, the food-making tissue (see 1 190), while the internal\\ntissues may be used for storage of reserve food.\\nEXERCISE VII.\\nBladder Wrack. (Facits vesiculosus). Place a plant in a glass dish or\\na pan of water. Observe\\n1. The general form of the body or thallus its mode of branching.\\na 34.)\\n2. The thicker central region forming a midrib, with thinner wings.\\n(Eigs. 27, 28.)\\n3. Downwards, the thickening of rib and death of wings to form stalk\\nnear base.\\n4. The lobed attachment disk at base of stalk.\\n5. The swollen regions of the wings here and there. Cut into one of\\nthese and observe that it is a bladder.\\n6. The notched tips of some branches the enlarged and more or less\\ndistorted tips of most, forming the receptacles.\\n7. Scattered on the thallus minute elevations, from which protrude\\nthrough an opening at the top a tuft of fine hairs. These are the mouths of\\nthe hair pits. (Fig. 28.)\\n8. Crowded on the receptacles, larger warts with a hole at top and sim-\\nilar protruding hairs. These are the mouths of larger pits, conceptacles\\nwhich contain the sex-organs.\\nCut two thin transverse sections of the thallus, one through the bladder\\nand the other through the general thallus. The latter should include a\\nhair pit. Examine them with a lens and observe\\n9. In the latter, the denser outer tissues the cortical region the looser\\ninner ones, of elongated threads and much mucilage, the medullary region;\\nthe thicker denser midrib; the form of the hair pit.\\n10. Note the difference between the structure of the bladder and the\\nunswollen wing. Which region is altered to form the bladder", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0034.jp2"}, "35": {"fulltext": "THE THALLUS OF THE HIGHER ALGM. 29\\n39. Summary. Comparing the thread-form with the thin\\nbroad algae, we find the body of the latter often nearly as\\nsimple but, when the body is thicker, it is often seen to con-\\nsist of unlike regions. The outer parts are arranged so as to\\nenable the plant to make food for itself by getting the proper\\nmaterial from the water and absorbing the light that falls\\nupon the surface. The inner parts, being too much shaded\\nby the outer to serve for food making, are used for other pur-\\nposes. Special organs for floating the plant are formed in\\nsome of the brown seaweeds.\\nOther algae, of slender form, are more complex by having\\nthe older cells of an at first single row divided by partitions\\nparallel to the length into five or more cells.\\nWith greater complexity* of the body, growth in length\\nusually becomes localized at the tips where all the cells are\\nrapidly dividing.", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0035.jp2"}, "36": {"fulltext": "CHAPTER V.\\nTHE FUNGUS BODY.\\nFungi are plants without the green coloring matter chloro-\\nphyll (see U 6), whose body is generally made up of long\\nfilaments, either loosely or densely interwoven and united.\\n40. Origin. As the bacteria (see ^j 14), the smallest and\\nsimplest plants, were probably derived from the lowest algae\\nby slowly adapting themselves to get ready-made food, so, at\\nvarious times in the past and therefore at various points in\\nthe ascending scale of algal life, certain algae have adapted\\nthemselves to the use of food which they could secure from\\nother beings. Then, having no use for the chlorophyll and\\nchloroplasts, they have gradually lost them. The adoption\\nof the habit has proved highly successful, both among the\\nsimple bacteria and the more highly organized true fungi.\\nThe ancestors of the present species were how long ago no\\none can say probably at first chiefly, if not exclusively,\\naquatic. Some, at the present time, have the same habit,\\ngrowing in infusions of organic matter. Others attach them-\\nselves to dead or even living animals or plants in the water.\\nThe bodies of dead or living organisms furnish places of growth\\nfor a great number of species which have adapted themselves\\nto other than aquatic life. Many live in the soil because it\\ncontains in its upper layers more or less organic matter from\\nthe offal of plants and animals, or from their dead bodies.\\n41. Hyphae. The filaments of which the fungus body is\\ncomposed are called hyphae. Each is the result of growth\\n30", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0036.jp2"}, "37": {"fulltext": "THE FUNGUS BODY.\\n31\\nfrom a single cell, and is comparable to the thread-like body\\nof the filamentous algae.\\nThere is, naturally, a great variety in the hyphae of differ-\\nent species of fungi. Some are relatively large others very\\nsmall some of even diameter and caliber, others irregular\\nand with unequally thickened walls some very thin- walled,\\nothers very thick-walled. Between these extremes is to be\\nfound a complete gradation.\\nThey grow in length at the apex only. In many kinds\\npartitions are formed at more or less regular intervals, as the\\ngrowth in length proceeds, while in others no partition-walls\\nare formed. Even when transverse partitions form, they do\\nnot separate the filaments into cells, but each chamber, or\\nsometimes the whole filament, represents several or many\\ncells. (Compare 26.)\\n42. Branching. As the hyphae elongate, branching may\\noccur. If a branch is to be formed, a limited area of the\\ncell-wall begins to grow more rapidly than the rest. This\\nallows a slight bulging of the growing region the swelling\\nincreases and soon takes the form of\\na branch, like the main axis. It may\\nremain short or continue to grow\\nindefinitely in length. Commonly a\\ncross-wall is formed at the base of the\\nbranch. If such a branch arises first\\nas a minute pimple, so that it remains\\nconnected with the parent axis by a\\nsmall neck, and has only limited\\ngrowth in length, it is called a bud\\nand the process is known as budding\\n(fig. 29). Such branches are usually\\neasily broken off, thus readily produc-\\ning independent plants. (See further\\nunder Reproduction, 261.) In some species of fungi,\\nFig. 29. Beer-yeast {Saccharo-\\nmyces cerevisice). a, a full-\\ngrown plant with a branch\\n(bud) partially developed, b,\\nc. colonies formed by budding,\\nthe individuals still attached.\\nMagnified 750 diam.\u00e2\u0080\u0094 After\\nReess.", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0037.jp2"}, "38": {"fulltext": "32\\nOUTLINES OF PLANT LIFE.\\nprofuse branching is the rule in others, the branches are\\nfew.\\n43. Mycelium. When branching is profuse, or when a\\nconsiderable number of individuals grow near together, the\\nfilaments often become interwoven and entangled in so com-\\nplex a web that it is impossible to follow a single hypha for\\nFig. 30. A single plant of Mucor Mucedo, showing the mycelium as it developed from\\na single spore. It bears a single erect reproductive branch rising above the fluid.\\nMagnified 25 diam. After Brefeld.\\nany distance. Such a mat of hyphae is called a mycelium, a\\nterm which is also used to designate the vegetative hyphae\\ncollectively, whether forming a felted mass or not (figs. 30,\\n31). The mycelium may be formed wholly upon the surface\\nof the object upon which the fungus lives or part of it may", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0038.jp2"}, "39": {"fulltext": "THE FUNGUS BODY.\\n33\\nlie on the surface, and part may penetrate that object or all\\nof it may be hidden within the substratum.* In some of the\\ncommon molds (Mucorini), the cobwebby threads lying upon\\nthe surface of the substratum constitute the exposed part of\\nthe mycelium, while other hyphae penetrate deeper in\\nothers (Penicillium, etc.), the superficial hyphae become so\\nFig. 31. A section of part of the aerial body of Polyporus. sp, hyphae running at an\\nangle to the section, cut across K crystals of oxalate of lime. Magnified about 500\\ndiam.\u00e2\u0080\u0094 After Vogl.\\ninterwoven that they may be lifted off the substratum (as\\nfrom jellies, jams, syrups, etc.) as a coherent layer. But in\\nmost cases, especially when the fungus grows on a solid\\nmedium, the hyphae become adherent to it and permeate it\\nso that they cannot be separated from it, even by the most\\ncareful dissection.\\nThis non-committal term may be used to designate the material upon\\nwhich the vegetative part of the fungus grows, whether it be a living\\nbody, a dead organism, or organic matter in solid or liquid form.", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0039.jp2"}, "40": {"fulltext": "34 OUTLINES OF PLANT LIFE.\\nEXERCISE VIII.\\nBlack mold {Rhizopus nigricans). Before any white or black dots ap-\\npear on the mold examine the vegetative hyp ha. 41.) These are of\\ntwo kinds, (a) those running over the surface of the bread (b) those\\npenetrating it.\\n1. Examine a. Lift up a few threads with a needle and mount them\\nin water. Study with a lens. Are they white or colorless Why\\nthen is the body composed of them (the mycelium, 43) white\\n2. Examine b. With needles tease out hyphse from a bit of bread in\\nwater free them as far as possible from the dehris and mount. Com-\\npare with a.\\nAfter mold has begun to show black dots (spore cases, ^[271) examine\\n3. Determine how the branches are placed which bear the spore cases.\\n(Fig- 30-\\n4. Compare the white (young) and black (mature) spore cases. Can\\nyou find the very smallest ones\\n5. Snip off a few ripe spore cases with scissors, handling them cau-\\ntiously to avoid breaking or tangling them mount in alcohol and ex-\\namine. Crush (if not already broken) and observe numerous dust-like\\nparticles, the spores, which escape. (Fig. 146.)\\n44. Parasites. Especially is this true of those fungi\\nwhich grow in the interior of living organisms. The higher\\nplants are liable to be fastened upon by parasitic fungi, and\\ncompelled to act as hosts to their unbidden and unwelcome\\nguests. Such a host plant may be entered when a mere\\nseedling, in which case the fungus grows with its growth, or it\\nmay not be attacked until older or even mature. The host\\nmay be permeated in all its parts by the fungus filaments or\\ncertain members only, such as the leaves, flower parts or\\ntwigs, may be affected. The effect of the fungus upon the\\nhost is often scarcely visible to the unaided eye sometimes\\na local disturbance is manifested by swelling, unnatural color\\nor growth sometimes the affected members become distorted\\nBecause water will not wet them. Replace alcohol as it evaporates\\nit does so rapidly.", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0040.jp2"}, "41": {"fulltext": "THE FUNGUS BODY. 35\\nand useless or are even killed j sometimes the disease is gen-\\neral and is followed, slowly or quickly, by general death of\\nthe host. (See further ^j 184, 369.)\\n45. Infection. These internal parasites obtain entrance to\\ntheir hosts in various ways. Sometimes the young hypha,\\ngrowing from a special reproductive body (spore),* so min-\\nute that it may easily float in the air and fall upon a leaf,\\ncreeps along the surface till it finds one of the microscopic\\nopenings in the skin of the leaf, into which it grows (sfi, fig.\\n32). These external openings are connected with irregular\\nFig. 32. Young hyphse of Exobasidittm developing from spores, s/ entering the\\nair-pores of the leaf of the cranberry. Others, from s/ sp penetrate the skin\\ndirectly. Magnified about 600 diam. After Woronin.\\nspaces between most of the cells of the softer parts (fig. 106),\\nwhich are also the parts in which the food-supply is most\\nabundant. In these, therefore, the fungus develops, break-\\ning out to the surface again to form or set free its reproduc-\\ntive bodies.\\nOr, the young hyphae may excrete at their tips a substance\\nSee ^f 263 and the following.", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0041.jp2"}, "42": {"fulltext": "36\\nOUTLINES OF PLANT LIFE.\\nwhich so softens or dissolves the cell -walls of the host that\\nthey penetrate these cells readily, not only at the surface\\n(sp sp fig. 32), but in the interior.* They then branch\\nfreely, often growing in the spaces\\nbetween the cells, often passing through\\nthe cells themselves (fig. 33).\\nPlants are often attacked when mere\\nseedlings. From either a bit of my-\\ncelium or a spore that has survived\\nthe winter or the dry season, a hypha\\ngrows, which, almost as soon as the\\nseedling emerges from the seed, pene-\\ntrates it. The fungus, in these cases,\\nmay develop quickly and kill the young\\nplant (as in the damping off disease\\nin greenhouses), or it may develop slowly\\nand not reach its maturity until the host\\nis also mature.\\n46. Haustoria. Those fungi which\\ngrow upon the surface of living plants\\n(and those which grow in the internal\\nair-spaces) often have special branches\\nfor fastening themselves to the host or\\nHyphae of Tm- absorbing food from it. In the surface\\n111, tes Pirn perforating at c\\nthe walls of a wood-ceil of lungi these are usually very snort, disk-\\nScotch pine and destroying iiji t, v i a\\nthe primary wail of the ceil, like or Jobed branches which do not\\ni, e, holes made by hvphae. t\\nMagnified about 800 diarn. penetrate the cells 01 the host. In\\n-After R. Hartig.\\nother cases they are branches of minute\\ndiameter, which enter the cells, and either enlarge into a\\nknob (fig. 34) or branch profusely (fig. 35).\\nThe penetration of cell-walls is probably assisted by such pressure\\nas the growing hypha can exert.", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0042.jp2"}, "43": {"fulltext": "THE FUNGUS BODY.\\nFlG. 34. Epidermis and a few cortical cells of cowberry with mycelium of Calyptospora\\noccupying the intercellular spaces and pressing knob-like ends against the cells from\\nwhich a slender branch penetrates the wall and enlarges in the interior into sac-like\\nhaustoria, b, b. a, c, reproductive branches. Magnified 420 diam. After R. Hartig\\nEXERCISE IX.\\nMildew {Microsphara), a surface parasite. Examine dried leaf bear-\\n1. The whitish interlacing hyphse on surface of leaf, forming the\\nmycelium. 43.)\\n2. The distribution of the fungus does it cover the whole leaf or only\\noccur in patches Compare the earlier and later gathered leaves as to\\nthis.\\n3. Demonstration. Scrape a bit of the mycelium from the surface of\\nthe leaf after moistening it for a few minutes with a 5$ solution of\\npotassic hydrate. Mount and show (a) the colorless branching hyphse\\n{b) the erect branches bearing the spores (c) the spores.\\n4. Examine, as before, one of the older leaves. Observe the yellow-\\nish dots scattered over the mycelium, the immature fruits. Associated\\nwith these the black mature fruits, which contain sporangia with\\nspores. 271.)\\nWhite fust {Cyst opus portu/acce), an internal parasite.\\nI. Demonstration. Boil a leaf of purslane for a minute or two in\\npotassic hydrate. Tease apart the tissues of leaf with needles on a slide,", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0043.jp2"}, "44": {"fulltext": "38\\nOUTLINES OF PLANT LIFE.\\nmount and show the mycelium of the fungus consisting of tangled hyphse\\nramifying among the cells of leaf. (UH 44, 45-)\\nExamine a dried leaf. Observe\\n2 The white blisters [spore beds) here and there on the surface the\\nthin membrane (the epidermis of the leaf) by which they are covered\\nin older blisters the cracking and final disappearance of this skin.\\n269, fig. 141.)\\n3. The white powdery scores which jar out or can be dislodged with\\nneedle.\\n47. Fusion.\u00e2\u0080\u0094 When the hyphse of a fungus grow very close\\ntogether, they frequently cohere and become so changed in\\nappearance as to lose all trace of resemblance to filaments.\\nNot only fusion but thickening and division occur, and a\\nsection of the resulting structure has much the appearance of\\nFig. 35-\\nFig. 36.\\nbSinfthereta The other contents of host-cells not shown. Magmfied about 400\\nSflaments recognizable. The dark spheres are imprisoned alga,. Magnified 650 diam.\\nAfter Bornet.\\na section of the tissues of a higher plant (fig. 36)- These\\nchanges are particularly apt to occur at and near the surface", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0044.jp2"}, "45": {"fulltext": "THE FUNGUS BODY. 39\\nof the more massive parts, where they are necessary to impart\\nfirmness, rigidity, or durability.\\nThe interweaving and fusion of the hyphae sometimes pro-\\ndace cord-like or strap-like structures of considerable size.\\nThe mycelia of the higher fungi frequently form them, and\\nthey may be found in the leaf-mold of forests or in rotten\\nstumps or between boards in wet places.\\n48. Lichens. The body of lichens is a mycelium woven\\nabout the simpler algae, rarely about other small green plants,\\nwhich are thus imprisoned. The fungus hyphae usually pre-\\ndominate and in great measure determine the form of the body\\nand its texture. Sometimes the algae are present in such\\nnumbers that the hyphae seem merely distributed among them.\\nIn form the body maybe broad and thin (fig. 215), or slender\\nand shrub-like in some cases it is so thin and adherent, or so\\ninterwoven with the substratum, that it seems to form a mere\\ncrust over it. In texture it may be tough and leathery, with\\nthe hyphae near the surface fused into a false tissue [a, b, fig.\\n36). When gelatinous algae, such as Nostoc (see n) are\\nimprisoned, the body may be gelatinous while wet. In all\\ncases the algae supply the fungus with food, and are in turn\\nsupplied with water absorbed by the spongy mycelium. (See\\nfurther ft 164, 185, 367.)\\nEXERCISE X.\\nLichen {Physcia stellaris). Soften a plant by soaking it in water for\\na few minutes. Observe\\n1. The mycelium, forming a connected leaf-like lobed thallus. Com-\\npare as many other forms as are available. 48, fig. 215.)\\n2. Compare the color when dry and wet. In the latter condition, the\\nmycelium is more translucent and the imprisoned green algse show\\nthrough more plainly. (Figs. 36, 216.)\\n3. The tufts of hyphae extending from lower surface to bark, the hold-\\nfasts or rhizines.\\n4. Occupying the central region on the upper surface, the round\\ncolored disks, the clusters of spore cases.", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0045.jp2"}, "46": {"fulltext": "40 OUTLINES OF PLANT LIFE.\\nCut a vertical section through a part of the thallus. Observe\\n5. The layers of the thallus above and below, dense layers, the\\nupper and lower cortical layers between them, the medullary layer,\\nwith green algce distributed unequally through it. (Fig. 36.)\\n49. Summary. The fungi, though descended from the\\nalgae, have adapted their body to new conditions of life so\\ncompletely that it shows little resemblance to that of the algae.\\nAll have colorless (non-green) bodies, composed of slender\\nhyphae, frequently much branched and interwoven, and either\\napplied to the surface or penetrating the substratum. Some\\nkinds live on dead organic matter (saprophytes); some are\\nexternal and some internal parasites. The latter enter the\\nhost through pores, or by perforating the skin, often causing\\ndeformity or disease or death. When strength or protection\\nor durability is necessary, the hyphae may become insepara-\\nbly fused into a false tissue. Lichens are special kinds of\\nfungi, associated for life with simple algae from which they\\nderive their food.", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0046.jp2"}, "47": {"fulltext": "CHAPTER VI.\\nLIVERWORTS AND MOSSES.\\n50. Alternation of generations. In the liverworts and\\nmosses, as in all the plants higher in the scale, there occur\\ntwo well-marked phases in the course of their lives. One of\\nthese phases is marked by the formation of sexual repro-\\nductive cells, or gametes, the egg and sperm (see 304),\\nwhence it is called the sexual phase, or the gametophyle. The\\nother is characterized by the formation of non -sexual repro-\\nductive cells, the spores (see 263), whence it is called the\\nnon-sexual phase, or sporophyte. These two phases alternate\\nwith each other i.e., the eggs produced by the gametophyte\\ndo not form a new gametophyte but a sporophyte and the\\nspores of the sporophyte do not form a new sporophyte but a\\ngametophyte. Representing the gametophyte by G and the\\nsporophyte by S the sequence is G^-^S^-^G-m-^S-m-^G^-^S,\\nand so on, generation after generation. Often the gameto-\\nphyte forms other gametophytes repeatedly, but usually the\\nsuccession is interrupted, sooner or later, by the formation of\\nfertile eggs and from these a sporophyte. In such cases the\\nsequence may be represented thus: GGGGm-^Sw^ GGG^-^S\\nGG, etc. The sporophyte of these plants never propagates\\nits own form. To this regular sequence of the two phases\\nthe phrase alternation of generations has been applied.*\\nRather obscure suggestions of the alternation of generations are to\\nbe found among the algge and fungi, but they are not definite enough to\\nwarrant discussion in this book. Let the student notice, however, that\\nthis feature does not appear suddenly in plant life, though introduced\\nabruptly into the account of it.\\n41", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0047.jp2"}, "48": {"fulltext": "42 OUTLINES OF PLANT LITE.\\nIn each phase, a body of form and structure suited to its\\nspecial work is produced. In the higher liverworts and\\nmosses both phases have nutritive work to do, but in many\\nthis is confined to the gametophyte, and in all the gameto-\\nphyte carries on the greater part of it. To this phase, there-\\nfore, attention is first given.\\nLiverworts.\\n51. The thallus. The form and structure of the vegeta-\\ntive body of the simplest liverworts is scarcely different from\\nthat of some of the green algae. The body is a thallus with\\nrhizoids (fig. 37). The rhizoids are usually filaments arising\\nFig. 37.\u00e2\u0080\u0094/}, plants of Riccia sorocarpa, on the ground. Gametophyte phase. Nat-\\nural size. B, a vertical section of one of the thick lobes of the thallus, showing nearly\\nuniform structure. The thallus has nearly covered over two young sporophytes\\nwhich appear as though in the interior. Rhizoids arise from the ventral side and\\nflanks. Magnified about 25 diam. -After Bischoff.\\nfrom the under side and flanks of the thallus. They serve to\\nfasten the thallus to the substratum, and perhaps assist it in\\nabsorbing water. The thallus is usually thin and flat, though\\nsometimes much crisped. Most liverworts lie broadside to\\nthe substratum. Very rarely is the thallus erect and attached\\nby a narrow stalk.\\n52. The dorsiventral thallus. In the simplest forms the\\nthallus is uniform in structure from upper to under side. In\\nothers there is a decided difference between the two sides.\\nThe upper part is green, while the under is not. In one\\nfamily there are large air-chambers in the upper part of the", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0048.jp2"}, "49": {"fulltext": "LIVERWORTS AND MOSSES.\\n43\\nthallus, from the floor of which arise green filaments (fig. 38).\\nOn the under side, also, are frequently found scale-like out-\\ngrowths as in fig. 38, i.\\nA part which shows constant differences between an upper\\n(dorsal) and an under (ventral) side is said to be dorsiveniral.\\nFig. 38 Fig. 39.\\nFig. 38. Portion of a vertical section of the thallus of Lumilaria cruciata. a, dor-\\nsal, b, ventral epidermis c, an air-pore e, air-chamber, from whose floor rise green\\nfilaments, d\\\\ f, partition between adjoining air chambers e, colorless cells contain-\\ning starch, some showing net-like thickenings of the walls, others with oil-bodies, h\\ni, a ventral scale a rhizoid. Magnified no diam. After Nestler.\\nFig. 39. Lunularia cruciata, showing horizontal thallus and rhizoids with two erect\\nbranches (one young, one mature), for carrying sex-organs. Natural size. -After\\nBischoft.\\nThese differences are usually called forth by the action of\\nlight (see f 325).\\n53. Branching. The branching of the thallus is always\\nby forking, in a single plane or direction, as in Fucus, but\\nthe branches do not always develop equally. Sometimes\\nspecial branches, instead of remaining horizontal, grow up-\\nright and develop into peculiar forms adapted to producing\\nthe sexual reproductive organs (fig. 39).", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0049.jp2"}, "50": {"fulltext": "44 OUTLINES OF PLANT LIFE.\\nEXERCISE XL\\nA thallose liverwort {Marchantia polymorpha). Examine an entire\\nplant in water. Observe\\ni. The flattened horizontal body [thallus) with central line, the mid-\\nrib, and thinner wings on each side.\\n2. The notched apex (the wings outgrow the midrib somewhat).\\n3. The mode of branching (forking). Examine the tips and find one\\njust branched. Do not confuse with notch of apex when a tip branches\\nthere will soon appear two notches. Docs the branch appear on the\\nside of the older thallus, or are the branches equal at first Are they\\nequal when older? 53.)\\n4. The green lens-shaped bodies [brood-buds) growing at certain spots\\nalong the midrib, surrounded by an outgrowth which forms a cupdike\\nrim about the cluster. Remove a brood-bnd and observe its form,\\nespecially in full grown ones the two opposite notches, the growing\\npoints. (1 297, fig. 177.)\\n5. The air-chambers {areola) of the upper part of the thallus, showing\\nthrough the skin, best seen in older parts and with a lens. What is\\ntheir form? Are they all alike 52.)\\n6. The openings into the air-chambers, in the skin over each one,\\nlike a little pinhole.\\n7. Compare the under surface with the upper. Observe the numerous\\nhairs. Discover the difference in place of origin and direction of\\ngrowth of these. 51.)\\n8. Carefully pull off with forceps as many of these hairs as possible\\nand notice the dark-colored overlapping outgrowths along the midrib,\\ncurving outward as they are followed forward, attached along their\\nedges. These are the so-called leaves.\\nCut a transverse section of the thallus through a brood-bud cup.\\nObserve\\n9. The origin of the brood-buds (only the younger still remaining) over\\nthe midrib.\\n10. The difference between tissue of upper and under parts of thallus.\\n(If fresh plants are available observe especially the difference in color.)\\n11. Demonstration. Cut a very thin transverse section of the thallus.\\nSelect a part passing through stoma and show\\n(1) The air-chamber its roof, the skin, with chimney-like stoma in\\ncenter its sides a vertical plate of cells its floor, with branched fila-\\nments of chlorophyll-bearing cells. (Fig. 38.)", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0050.jp2"}, "51": {"fulltext": "LIVERWORTS AND MOSSES.\\n45\\n(2) The large-celled colorless tissue forming the lower half of section\\nthe sections oi leaves arising near midrib and concave towards center.\\n54. The shoot. In the greater number of liverworts the\\nmature vegetative body is a shoot, which is differentiated\\ninto stem and leaves (figs. 40, 41). Even in such a body\\nthe dorsiventral character is well\\nmarked. The stem is slender\\nand bears three (rarely more\\nor fewer) rows of leaves, of which\\nthe two dorsal rows are the larger,\\nFig. 40. Fig. 41.\\nFig. 40.\u00e2\u0080\u0094 Gametophyte of Bazzania Nov ce- Ho Hand ice. Besides the ordinary branches\\nthere are slender ones (fiagella) with sparse minute leaves. Natural size. After\\nLindenberg and Gottsche.\\nFig 41. A dorsal view ventral view of a piece of fig. 40, magnified about 12\\ndiam., showing the stem, bearing two dorsal rows of large leaves and one ventral\\nrow of small ones.\u00e2\u0080\u0094 After Lindenberg and Gottsche.\\nwhile the under leaves are much smaller, even to being incon-\\nspicuous or wanting. These leaves consist of a single sheet\\nof uniform cells richly supplied with chloroplasts, as are also\\nthe outer cells of the stem. Their form is very varied and\\noften of great beauty. They are usually crowded so closely\\nas to overlap each other more or less, and hide the stem\\ncompletely (fig. 41).", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0051.jp2"}, "52": {"fulltext": "46 OUTLINES 01 PLANT LIFE.\\nEXERCISE XII.\\nA leafy liverwort {Porella platyphylla).\\ni. In what position do the plants grow with reference to the sub-\\nstratum\\nDisentangle carefully a single plant.* Observe\\n2. The growing apex the dying base the distinctly dorsiventral\\nhabit. Enumerate the differences between the upper and under sides.\\n(II 54-)\\n3. The mode of branching a central axis, with lateral branches,\\nthemselves with lateral branches i.e., monopodial and bipinnate. 58.)\\n4. The yellowish or brownish stem, covered with leaves unequally\\ndistributed.\\n5. The two rows of large leaves on the upper flanks of the stem.\\nHow do they overlap Turn the shoot over and note a third row of\\nsmall underleaves in the center below also right and left the lobes of\\nthe upper leaves. Determine the form of the under and upper leaves.\\nMake an enlarged paper pattern of the latter showing how their ventral\\nlobes are arranged. (Figs. 40, 41.)\\n6. Demonstration. Mount a leaf and point out the uniformity of cells\\nand their abundant chloroplasts.\\nMosses.\\nIn the mosses the complexity of the mature vegetative body\\nis somewhat greater. It is always developed as a shoot dif-\\nferentiated into stem and leaves.\\n55. Rhizoids. The shoot is anchored, as in the liver-\\nworts, by numerous usually much branched rhizoids (A, fig.\\n42 w, fig. 43). Similar filaments may be produced, often\\nin great numbers, along the stem and especially inthe axils\\nof the leaves, or they may even arise from the leaves them-\\nselves, when the plants grow in dense patches or in a very\\nmoist place.\\n56. The stem is usually cylindrical and covered by the\\ncrowded leaves. In structure it generally shows an advance\\nupon that of the liverworts, which is nearly uniform, in hav-\\nIf dry, first soften by placing plants in hot water for a few minutes.", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0052.jp2"}, "53": {"fulltext": "LIVERWORTS AND MOSSES.\\n47\\ning the whole of the outer region occupied by a distinct mass\\nof mechanical tissue for stiffening the stem, and, near the\\ncenter, a strand known as conducting tissue, which may\\nact as a line of transfer for water or food.\\nFig. 42. A, gametophyte of Polytrichum commune, with rhizoids below. B, gameto-\\nphyte of tlylocomitini splendens, bearing three sporophytes near top. Natural size\\n\u00e2\u0080\u0094After Kerner.\\n57. The leaves are also more highly developed than in\\nliverworts. They are always sessile and are arranged in two\\n(rarely), three, or more vertical ranks along the stem, and\\nconsist usually of a single sheet of green cells, the blade (figs.\\n43, 44), and a central rib running from base to apex (fre-\\nquently wanting), which is composed of elongated conduct-\\ning and strengthening cells (figs. 43, 44). In some the", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0053.jp2"}, "54": {"fulltext": "43\\nOUTLINES OF PLANT LIFE.\\namount of green tissue is increased by the formation of verti-\\ncal plates similar to the blade (fig. 44).\\n58. Branching. The stem branches, often very profusely.\\nSometimes the growth of the lateral branches, as of the\\noriginal main axis, is checked by the formation of sex organs.\\nIn that case a new branch is likely to arise some distance\\nFig. 43. Fig. 44.\\nFig. 43. A, leaf of a moss {Funaria Americana), showing central rib. Magnified\\nabout 40 diam.; B, upper portion of the same leaf, highly magnified, showing single\\nlayer of cells forming the blade and the narrower cells of the thick rib \u00e2\u0080\u0094After\\nSullivant.\\nFig. 44. Tip of leaf of a moss (Oligotrichum aligerum), showing the thickened\\nrib, and the plate-like ridges on. blade and rib greatly increasing the surface of\\nnutritive tissue. Magnified about 75 diam. After Sullivant.\\nbelow the apex, so that the stem is merely a succession of\\nlateral branches (fig. 45). This mode of branching is called\\nsympodial. In other cases the main axis continues its growth\\nunchecked, and more or fewer branches also develop. These\\nlie plainly upon the sides of a central axis. This mode of\\nbranching is called monopodia/. Often the growth of the\\nlateral axes is definitely limited and their development regu-\\nlar, forming a pinnate branch-system. If the secondary axes", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0054.jp2"}, "55": {"fulltext": "LIVERWORTS AND MOSSES.\\n49\\nthemselves branch, there is formed a bipinnate or even tri-\\npinnate system, as in figure 42, B.\\n59. Protonema. In its early stages the vegetative body\\nof the leafy liverworts and the mosses is either a flat thallus,\\nsimilar to the mature form of the\\nthallose liverworts, or a branching\\nfilamentous body, called the pro-\\ntonema, almost identical with the\\nform of the branched filamentous\\nalgae. Upon this protonema the\\nleafy shoot arises as a lateral bud,\\nwhich soon outstrips it in growth\\nand develops leaves. The pro-\\ntonema may live for some months,\\nbut generally perishes after having\\nproduced a few leafy plants.\\n60. Sporophyte. The non-\\nsexual phase in the liverworts and\\nmosses has almost no vegetative\\nfunctions. It consists at maturity\\nof a yellowish or brown spherical or\\ncylindrical case (fig. 46), which is\\nsessile or raised upon a short or\\nlong stalk and contains (a few or)\\nhundreds or thousands of repro-\\nductive cells called spores. The\\npointed or swollen base of this\\nstalk is called the foot, and is embedded in the gameto-\\nphyte fig. 47) to absorb food from it.\\n61. Nutrition. The surface of the young sporophyte,\\nwhen large and well developed, as it is in the higher liver-\\nworts and mosses, is green. To a limited extent, therefore,\\nit is able to make food but not sufficient for its needs, for\\nthese are great on account of its rapid growth and the amount\\nFig. 45.\u00e2\u0080\u0094 Axis of a moss {Ortho-\\ntrie hum) showing sympodial\\nbranching. S 1 6 2 S 3 A 4 suc-\\ncessive clusters of sex-organs,\\nproduced at apex, which check\\nthe growth or axis. Beneath\\neach a lateral growing point\\ndevelops, producing successively\\nthe branches b 1 b 2 b s Magni-\\nfied 10 diam. After Bruch\\nSchimper.", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0055.jp2"}, "56": {"fulltext": "5o\\nOUTLINES OF PLANT LIFE.\\n4/w-,\\nFig. 46 A, two capsules of Bryum from the right-hand one the lid has fallen, show-\\ning the teeth. Magnified 5 diam. four gametophyte shoots of Splachnuni am-\\nput lace u in, bearing four sporophytes. Natural size. C, a capsule of one of the\\nsame sporophytes, showing enlarged apophysis, a, below the spore case, s. Mag-\\nnified 10 diam. D, capsule of Splachnuni luteum, with umbrella-like apophysis, a,\\nbelow spore case, j. Magnified 2 diam.\\nrequired to supply each spore.\\nThe foot, being in close contact\\nwith the tissue of the gameto-\\nphyte, acts as an absorbing organ,\\nreceiving food solutions from it.\\nThe sporophyte thus lives, in\\npart at least, as a parasite upon\\nthe gametophyte.\\nIn some mosses there is a tendency\\nto increase the nutritive work of the\\nsporophyte by developing at the top\\nof the stalk, below the spore case, a\\nmass of green tissue. In Bryum {A,\\nfig. 46) this gives the capsule a pear-\\nshape, while in Splachnuni C, D,\\nfig. 46) it is so far developed as to ex-\\nceed the spore case. In some species\\nit is expanded into a miniature um-\\nbrella which, one can imagine, might\\nreadily become divided into leaves.\\nThe intimate attachment of\\nsporophyte to gametophyte con-\\ntinues throughout the life of the\\nformer. Sometimes the gameto-\\nFig. 47. Young sporophyte of Phas-\\ncuni cuspidatum. c, columella f,\\nfoot, embedded in gametophyte stem\\ns, seta (cells not shown) sps, spore\\ncase sp, spore-mother-cells. Mag-\\nnified 80 diam \u00e2\u0080\u0094After Kienitz-Gerloff", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0056.jp2"}, "57": {"fulltext": "LIVERWORTS AND MOSSES. 5 I\\nphyte perishes at the close of the growing season, but more\\ncommonly it is perennial, growing and branching at the\\nanterior end as the older posterior parts die away.\\n62. Summary. Liverworts and mosses show a distinct\\nalternation of generations. The vegetative body of the sim-\\npler liverworts is a flat thallus, like that of the larger algae,\\nbut the higher forms have the central part developed as a\\nroundish stem, and the wings so branched as to form separate\\nleaves. The latter form is general in all the mosses, which\\nfurther have the stem and often the leaves stiffened by the\\ndifferentiation of mechanical tissues. The non-sexual genera-\\ntion in all is relatively small and depends for its food upon\\nthe sexual generation.\\nEXERCISE XIII.\\nA moss {Milium cuspidatum). Examine plants with capsules attached.\\nObserve the two connected plants\\n1. The leafy stemmed plant or gametophyte. (^[50.)\\n2. The slender plant attached to its tip, the sporophyte, consisting of\\na wire-like stalk, the seta, enlarged above to form the hanging capsule.\\n(16o, fig. 46.)\\n3. Boil for a few minutes in 5 per cent, potassic hydrate, rinse in\\nwater and gently pull sporophyte until it separates from the gametophyte.\\nObserve the smooth pointed end which was sunk in gametophyte. If\\nproperly separated no sign of tearing can be seen. (Fig. 47.)\\nExamine gametophyte in water. Observe\\n4. The differentiation of the body into stem and leaves.\\n5. The brown hairs (rhizoids) about the stem, which attach plant to\\nground. Do they branch (Tf 55-\\n6. The strength of the stem test it by breaking it with a lengthwise\\npull. Cut a thin transverse section and observe dark colored mechanical\\ntissues in outer region. 56.)\\n7. The form and structure of the foliage leaves note midrib of me-\\nchanical cells (test strength) latnina of one layer of cells large enough\\nto be visible under lens border of mechanical cells, some projecting\\npretty regularly as teeth. 57, fig. 43.)\\n8. Smaller, scale-like leaves on part of the stem.", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0057.jp2"}, "58": {"fulltext": "52 OUTLINES OF PLANT LIFE.\\nExamine sporophyte with mature capsule. Observe\\n9. The slender seta.\\n10. The thin yellow inverted capsule, from whose end a piece has\\nfallen leaving it open. 274, fig. 46.)\\n11. About the edge of the capsule a fringe of pointed projections,\\nteeth) curved inward, constituting the peristome. Break off these outer\\nteeth and notice the pale fringed membrane within, forming the inner\\nperistome or endostome. (Figs. 46, 148.)\\n12. Among these, or to be pressed out of capsule, many fine spores.\\nExamine young sporophytes of this or other mosses. Observe\\n13. The cylindrical form of the embryo sporophyte.\\n14. The hood covering its apex and carried up by it until the develop-\\ning capsule forces it off.\\n15. The lid which falls off to open capsule.", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0058.jp2"}, "59": {"fulltext": "CHAPTER VII.\\nFERNWORTS AND SEED-PLANTS.\\nFernworts.\\nAmong the still more complex plants, the ferns and their\\nallies, the same alternation of generations can be seen.\\nThe two generations, or phases, have, however, changed\\nmuch in relative size. Whereas in the liverworts and mosses\\nthe gametophyte is much the larger and more conspicuous,\\nas well as the longer-lived, among fernworts the sexual phase\\nis so much smaller that it is seldom seen and in some\\nspecies it is almost microscopic. On the other hand, the\\nsporophyte is the phase which is usually\\nseen and the only part popularly known.\\n63. The gametophyte. The vege-\\ntative body of this phase of the fern-\\nworts iu its best developed forms is a\\nsmall, flattened, green body of oblong,\\norbicular, or cordate outline, commonly\\nless than half a centimeter in diameter,\\nrarely as much as 2 cm. (fig. 48). It\\nis strikingly like a thallose liverwort in\\ngeneral form, being distinctly dorsiventral\\nand having rhizoids on its under side,\\nwhich fasten it in place. Only the central\\npart of the gametophyte consists of more\\nthan one layer of cells. On the under\\nside of this central cushion, as it is called, are borne the\\nsex organs.\\n53\\nFig. 48 \u00e2\u0080\u0094Ventral side of\\nthe gametophyte of a\\nfern, Asftleniuvi. The\\nnotched end is the an-\\nterior. Rhizoids near\\nposterior end. The small\\ncircles show position of\\nmale organs the chim-\\nney-like projections near\\nanterior end the female\\norgans. Magnified 10\\ndiam. After Kerner.", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0059.jp2"}, "60": {"fulltext": "54\\nOUTLINES OF PLANT LIFE.\\n64. Reduction of gametophyte. In a few of the fern-\\nworts the gametophyte is filamentous, or tuberous, and more\\nor less completely subterranean and colorless such derive\\ntheir food from decaying plant-offal.\\nIn higher plants of this group the gametophyte becomes\\nstill further reduced in size and structurally simplified, until\\nin some species it is hardly more than a few cells surrounding\\nFig. 49. Sporophyte of a fern, Polvf odium vulgare, showing horizontal underground\\nstem, bearing secondary roots and leaves. Natural size. From Bessey.\\nthe sex organs. These reduced forms grow by the use of food\\nstored in the spore from which they originate. Thegameto-", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0060.jp2"}, "61": {"fulltext": "FERN WORTS AND SEED-PLANTS. 55\\nphyte of such species has lost wholly its vegetative character,\\nand is restricted in function to the production of the sex\\norgans.\\n65. The sporophyte. In contrast with the smallness and\\nsimplicity of the gametophyte is the relatively large size and\\ncomplexity of the sporophyte (fig. 49). It is always differ-\\nentiated into stem and leaves, and, with rare exceptions,\\nroots also. It is also noteworthy that, as compared with\\nmossworts, the chief work of nutrition has been shifted from\\nthe gametophyte to the sporophyte and this even when the\\ngametophyte has its largest size and greatest duration, while\\nnutritive work is wholly abandoned in the smaller forms.\\nThe sporophyte has also become the long-lived stage, the\\ngametophyte being usually transitory (only exceptionally\\nliving more than one season), while the sporophyte lives\\nthrough one season in the few annuals, and commonly for\\nseveral or even many years.\\n66. Members. The mature sporophyte is differentiated\\ninto root, stem, and leaves. The important adaptations of\\nthe structure and forms of these members are so similar to those\\nof the seed plants that they will be discussed in connection\\nwith them.\\nEXERCISE XIV.\\nMaidenhair fern [Adiantum pedatuni).\\nI. The Gametophyte.\\n1. Observe its shape and size the notch at the growing point (anterior\\nend); the dying (posterior) end; the thicker central region, with thin\\nwings. (T[ 63, fig. 48.)\\n2. On the under side, a cluster of rhizoids near the posterior end.\\n3. Compare this plant with the thalius of Marchantia.\\nIf gametophytes with young sporophytes attached are available, ob-\\nserve\\n5. That the young sporophyte is fastened to the under side of the gam-\\netophyte.", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0061.jp2"}, "62": {"fulltext": "56 OUTLINES OF PLANT LIFE.\\nII. The Sporophyte.\\nTaking the underground parts in a dish of water, observe\\nI. The slender wire-like roots. How are they branched (^[83 ff.)\\nWhere are they attached to the stem Trace an unbroken one to the tip.\\nThe following points can only be seen on roots carefully gathered and\\ncleaned. What difference of color near tip Can you find many fine\\ntangled root hairs Where present Where absent 73.)\\nCut a transverse section of an old root, mount and observe\\n3. The outer brown mechanical tissues (also used for storage). 78.)\\n4. The central whitish tissue, chiefly the stele, in which the visible\\nopenings are the larger vessels. 75.)\\n5. In what position does the stem naturally stand Observe its occa-\\nsional branching 89); the surface covered with chaffy scales; the grow-\\ning apex and dying base.\\n6. Its nodes and internodes the nodes are indicated by the attachment\\nof a single leaf at each the internodes are the intervals between the nodes.\\nHow are the leaves placed? 104.)\\nCut a transverse section of the stem and observe\\n7. The outer brown mechanical tissues (also used for storage).\\n108.)\\n8. The circular, oval, or C-shaped white tissues, most of which belong\\nto the stele. Trace the course of the stele through at least two internodes\\nby cutting a series of rather thick (1 mm.) sections, observing the mode\\nin which the stele branches to pass out into a leaf. Cut also a longitudinal\\nsection through the base of a leaf stalk and trace course of stele.\\n109.)\\nTaking a perfect leaf, dried under pressure, observe\\n9. The stalk or petiole, with its branches. Note the mode of branch-\\ning; the petiole divides into two equal divergent branches; each of these\\nforks, one branch carrying leaflets while the other again forks, and so on.\\nHHf 126, 128.)\\n10. The hardness of the mechanical tissues at surface of polished petiole.\\nII. The leaflets. Note (a) shape as to outline and margin, comparing\\nbasal, median, and terminal leaflets of any branch; (b) the veins, con-\\ntaining branches of the stele; (c) the green tissues between the veins\\n127.)\\n12. Demonstration. Strip off a bit of epidermis, mount and show (a)\\nthe irregular form of epidermal cells; (b) the intercellular openings with\\nguard cells (stomata). (^T 137.)\\n13. At the edges of the leaflets on the under side crescentic brown spots,\\nclusters of spore cases. 275, figs. 149, 150.)", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0062.jp2"}, "63": {"fulltext": "FERNWORTS AND SEED-PLANTS. $7\\n14. Boil a leaflet for a minute in water. With a needle turn back a\\nflap which covers the spore cases; observe that it is a specialized portion\\nof the edge of leaflet.\\n15. On the under side of the flap a mass of yellowish spheroidal bodies,\\nthe spore cases. Scrape away most of them and notice the relation of\\ntheir points of attachment to the veins.\\nMount some of the spore cases and observe\\n16. Their shape the stalk by which they were attached. (Fig. 236.)\\n17. The darker ridge, annulus, which serves to burst them when ma-\\nture. (Fig. 236.)\\n18. Study the manner of bursting. Tear a bit of indusium from a dried\\nspecimen previously soaked in water, removing most of the sporangia.\\nAllow it to dry while watching it with a lens, illuminating from above.\\n19. Demonstration. Mount sporangia and spores and show their\\nstructure, especially the annulus.\\nSeed-plants.\\n67. Development. Among the highest plants, those\\nwhich produce seeds, the differentiation of the body is essen-\\ntially the same as in fernworts. The alternation of sexual\\nand non-sexual phases is still traceable, though greatly\\nobscured by the extreme reduction of the gametophyte.\\nThis tendency to the reduction of the sexual phase, which was re-\\nmarked in passing from the mossworts to the fernworts, continues, until\\nin the highest seed-plants the gametophyte is wholly microscopic.\\nEven by the aid of the microscope, it is possible to identify only the sex-\\nual organs which it produces, and one or more cells which are, perhaps,\\nthe rudiments of its vegetative body.\\nThe sporophyte, consequently, is the only phase of the\\nseed-plant visible to the unaided eye.\\nThe body of the sporophyte exhibits the same members,\\nviz., stem, root, and leaf, having the same general form, and\\nsubject to the same modifications, as in the fernworts. An\\naccount of the vegetative members of the fernworts and seed-\\nplants occupies the following three chapters.", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0063.jp2"}, "64": {"fulltext": "58 OUTLINES OF PLANT LIFE.\\nEXERCISE XV.\\nMarsh Marigold {Caltha pahistris).\\ni. Examine the roots. Observe (a) their surface, wrinkled from short-\\nening; (b) their structure.\\n2. Cut a transverse section as in fern; observe that mechanical tissues\\nare wanting.\\n3. Bisect longitudinally the base of a plant. Observe, as shown by\\nthe origin of leaves, the variable length of internodes; at base the inter-\\nnodes are very short so that leaves are crowded in the middle the inter-\\nnodes are long and leaves distant; above, the internodes become shorter\\nuntil, in the flower, they are not developed and the leaves are very much\\ncrowded. 104.)\\nStudy one of the well developed foliage leaves 123). Observe\\n4. The broad rounded blade with slight branches (teeth) at the margin.\\n5. The long slender stalk, petiole, gradually passing into\\n6. The sheathing base, in upper leaves branched to form two stipules.\\n(IF 125O\\n7. Examine and compare the various forms of leaves (a) the lowest,\\nhaving sheathing bases without petiole or blade, passing gradually into\\n(b) the best developed foliage leaves; (c) these near the flowers losing pet-\\niole and diminishing blade, becoming bracts; (d) the yellow perianth\\nleaves; next within these the yellowish stamens; the flattened pod-\\nlike green carpels each forming a simple pistil. (f*[ 133, 134.)\\n(Further study of flcwer, p. 210.)\\n68. Summary. In fern worts and seed-plants the sexual\\ngeneration is small, often microscopic, while the non-sexual\\ngeneration is conspicuous and often long-lived. The nutri-\\ntive work of the gametophyte is either temporary, ceasing\\nwhen the sporophyte develops green leaves, or is entirely\\nwanting. The sporophyte forms stems, leaves, and roots and\\ndoes most of the nutritive work. These members are very\\nvarious in form and are described in the following chapters.", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0064.jp2"}, "65": {"fulltext": "CHAPTER VIII.\\nTHE ROOT.\\n69. True roots. It has been pointed out that, among the\\nlower plants, there are very many which possess structures\\nsimilar in form and function to the root, and by some called\\nby this name. Although these parts serve to hold the plant\\nin place, and perhaps to absorb material from the substratum,\\nthey are not to be looked upon as equivalent to the roots of\\nthe higher plants either in origin or structure. In the algae,\\nfungi, liverworts, and mosses, the gametophyte is the promi-\\nnent phase. In no case does the gametophyte produce true\\nroots. It is not until the sporophyte becomes an independent\\nplant that true roots are found in the vegetable kingdom. It\\nis, therefore, only among fern worts and seed-plants that these\\norgans are to be found. When the sporophyte is developed\\nas an independent plant, it becomes necessary for it to pro-\\nduce some organ capable of holding it in place, or of absorb-\\ning materials from the outside, or of doing both. The organ\\ndeveloped to meet this need is the root.\\n70. Primary and secondary roots. In accordance with\\ntheir origin, roots are either piimary or secondary. Primary\\nroots are the first formed roots, i.e., those which are de-\\nveloped directly by the young embryo. In both fernworts\\nand seed-plants the primary root is rarely wanting, but often\\nshort-lived, dying after the plant has established itself and\\nhas formed secondary roots to take its place. In many cases,\\n59", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0065.jp2"}, "66": {"fulltext": "60 OUTLINES OF PLANT LIFE.\\nhowever, the primary root persists throughout the life of the\\nplant.\\nSecondary roots are later formed. They are roots which\\narise upon stem or leaf, or even upon the primary root itself.\\nIn the last case they are distinguished from branches of the\\nprimary root, which arise in regular succession toward the\\napex, by originating out of this regular order. Secondary\\nroots are also called adventitious roots. They may take their\\norigin at any point upon any of the members. Their point\\nof origin will depend largely upon external conditions. A\\nwound may cause them to appear. They are especially likely\\nto be formed upon those parts which are in contact with the\\nsubstratum, or from those parts which are kept moist. Upon\\nstems they are most apt to appear near the nodes. (See\\n104.) If the plant as a whole is surrounded by very moist\\nair, roots may appear at any point of the surface. Secondary\\nroots arising thus upon a part of the plant exposed to the\\nair, and growing for all or part of their existence in the air,\\nare also called aerial roots. Familiar examples are to be\\nseen about the lower part of the stem of Indian corn, the\\nEnglish ivy, the poison-oak, the trunks of palms and tree-\\nferns. Secondary roots often arise in regular succession\\ntoward the growing apex of the stem, particularly in plants\\nwhich have creeping or subterranean stems.\\n71. Growing point. Primary and secondary roots do not\\ndiffer materially in their structure. Near the tip they consist\\nof a mass of actively dividing cells, the growing point of the\\nroot (compare ^j 87). The real tip of the root is covered by\\na mass of cells called the root-cap (ep, fig. 50), which is at-\\ntached only to the growing point. Since the cells of the\\nfree surface of the root-cap are older and firmer than the\\ninner ones and the growing point, and lie in front of them,\\nthey serve to protect these more delicate parts as the growth\\nconstantly pushes the apex forward through the soil.", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0066.jp2"}, "67": {"fulltext": "THE ROOT.\\n6\\\\\\nThe youngest parts of the root are very much alike, but as\\nthey become older they grow unlike. The just mature por-\\ntion of roots shows three characteristic regions, namely, (i)\\nan outer layer or layers, the epidermis (2) an inner region,\\nthe stele (3) between these, the\\ncortex.\\n72. 1 The epidermis usually\\nbecomes many-layered. At the\\napex it constitutes the root-cap\\n(ep, fig. 50). On the other\\nparts of the root it sometimes\\nsloughs off entirely, exposing\\nthe cells of the cortex itself, as\\nin the monocotyledons (lilies,\\ngrasses, sedges, etc.) or, more\\ncommonly, only the outer layer\\nsloughs off, leaving the inner-\\nmost as the covering of the\\ncortex. It is too delicate to be\\ndistinguished by the unaided\\neye, except at the tip and\\nfurther back where it produces\\nroot-hairs.\\n73. (a) Root-hairs. Those\\ncells which form the surface of\\nthe root, whether they be the\\noriginal epidermis or cortical\\nones which have been exposed\\nby its loss, usually develop a large number of hairs, known as\\nroot-hairs (figs. 51, 52).\\nFig. 50.\u00e2\u0080\u0094 Median longitudinal section\\nthrough the extremity of a root of\\nMarsilia. The larger triangular cell\\nnear center of figure is the apical cell.\\nThe segments from the inner faces\\nmay be readily traced backward\\nthus the dotted line ec points to the\\nfourth, c to the sixth segment from\\nthe posterior right-hand face of apical\\ncell, ep, root-cap (epidermis ec,\\ncortex c, stele en, endodermis\\n(part of cortex* e, pericycle (part\\nof stele) Magnified about ioo diam.\\nAfter Van Tieghem.\\nThese root-hairs are branches of the superficial cells (fig. 52), and may\\nbe looked upon as simple extensions of them, as the finger of a glove is\\nthe extension of its palm. Only one root-hair arises from a superficial\\ncell. They are usually unbranched and without transverse partitions.", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0067.jp2"}, "68": {"fulltext": "62\\nOUTLINES OF PLANT LIFE.\\nOnly in rare cases are they wanting. They live for a\\nshorter or longer time, but are always, as compared with the\\nduration of the root, quite, transient. The older part of the\\nroot, therefore, is without root-hairs because of their death.\\nFig. 51. Transverse section of a young root grown in soil, showing root-hairs with\\nadherent soii-particles, the cortex, and the stele. Magnified about 20 diam. After\\nP rank.\\nThe youngest part of the root is likewise free from them,\\nbecause they have not yet been produced. As the root\\ngrows in length, new root-hairs are continually being pro-", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0068.jp2"}, "69": {"fulltext": "THE ROOT.\\n63\\nduced and the older ones are dying at an equal rate, so that\\na zone of hairs is found only upon the younger parts of the\\nroots.\\n74. (b) The root-cap. If the finger be supposed to rep-\\nresent the root, a short finger-stall, if it were attached to the\\ntip of the finger, might be fairly taken to\\nrepresent the position of the root-cap.\\nOnly in rare cases is the root-cap entirely\\nwanting. Serving to protect the tenderer\\nportion of the root behind, the root-cap is\\nitself constantly exposed to injury. The\\nouter and older parts of the root-cap are,\\ntherefore, either worn away through me-\\nchanical contact or, dying, they degener-\\nate and break down into a slightly muci-\\nlaginous material which facilitates the\\npassage of the root through the substratum.\\nThis degeneration or the mechanical wear\\nis constantly repaired within at the grow-\\ning point. The thickness of the root-\\ncap, therefore, is maintained throughout\\nits existence without considerable change.\\n75. 2. The stele. Occupying the cen-\\nter of the root, and surrounded on all sides\\nby the cortex, is an aggregate of tissues\\ncalled the central cylinder, ox stele (figs. 51,\\n53). The most noticeable part of this are\\nthe groups of elongated cells or cell-\\nfusions,* called vascular bundles, or vas-\\ncular strands. These strands are of two\\nkinds, wood strands, specially for the con-\\nFig. 52. A nearly ma-\\nture root-hair, showing\\nstructure and relation\\nto superficial cell of\\nroot grown in water\\nand therefore not dis-\\ntorted as in fig. 51.\\nn, nucleus embedded\\nin protoplasm; vacuole\\nsingle and very large.\\nHighly magnified.\\n\u00e2\u0080\u0094After Frank.\\nThese are continuous chambers formed by the breaking down of the\\npartition-walls between the abutting ends of cells. They are usually de-\\nvoid of living contents.", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0069.jp2"}, "70": {"fulltext": "6 4\\nOUTLINES OF PLANT LIFE.\\nducting of water, and bast strands for carrying foods. (See\\n^[^y 172-174, 197.) They are so placed that they alternate\\nwith each other about the outer part of the stele (figs. 51,\\n53). The strands may be in contact with one another in\\nFig. 53.\u00e2\u0080\u0094 Transverse section of the stele and a portion of the surrounding cortex of the\\nroot of calamus s, s, innermost layer of cortex, adjoining outermost layer of stele\\nwood strands; fih, bast strands. In the center of the stele and between the\\nbundles is conjunctive tissue. Highly magnified.\u00e2\u0080\u0094 After Sachs\\nthe center, or the center of the stele may be occupied by\\na pith (fig. 53).\\nThe number of vascular strands constituting the stele is\\nvarious, being as few as four or as many as forty. The\\nordinary number, however, is from eight to twenty. (See\\nfig- 530\\n76. 3. The cortex generally consists of large thin-walled\\ncells which have become partially separated from one another,\\nleaving larger or smaller intercellular spaces (fig. 53).", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0070.jp2"}, "71": {"fulltext": "THE ROOT. 65\\n77. Duration. Even when the primary root persists\\nthroughout the entire life of the plant secondary roots often\\nappear. When the primary root perishes, its functions must\\nbe performed wholly by secondary roots, which are developed\\nin succession upon those parts where they are useful. The\\nsecondary roots themselves may be either permanent or\\ntransient. In creeping plants particularly, whether growing\\non land or in water, the functions of the root are likely to be\\nhanded on to successively younger roots, the old ones perish-\\ning and dropping off. If the roots endure for a considerable\\ntime, they may retain their primitive structure and form, or\\nthey may undergo secondary changes which unfit them for\\nabsorbing organs, and adapt them to subserve various special\\nfunctions.\\n78. Secondary changes. Shortly after any portion of\\nthe root has ceased to increase in length, and, therefore,\\nwithin the first season, it ordinarily undergoes minor second-\\nary changes which may or may not be followed by more\\nprofound alterations. These changes affect its primary\\nstructure in various ways and to various degrees according to\\nthe parts concerned.\\nIn some cases the older roots differ from the younger in\\nscarcely more than the loss of the external layer of cells, from\\nwhich the root-hairs arose. The sloughing off of this layer\\ncarries with it the hairs themselves and exposes the next inner\\nlayer of cells, which had before become slightly altered so as\\nto be rather impervious to water. Upon their exposure, this\\nalteration proceeds further, so that they become almost or\\nquite incapable of absorbing the soil-water to which they may\\nbe exposed. It follows from this that it is only the younger\\npart of the root, that is, the portion which has not undergone\\nsecondary changes, which is capable of absorbing water. In\\nmany roots this is the only change which occurs. In a\\ngreater number the root is also strengthened.", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0071.jp2"}, "72": {"fulltext": "66\\nOUTLINES OF PLANT LIFE.\\nIn a large number of roots, the secondary changes result\\nin increasing the diameter, sometimes very greatly, by the\\nformation of concentric layers of new tissue in two or more\\nregions, called the cambium regions.\\nThe outer growing layer, or cork cambium, usually formed in the\\ncortex, produces tissues which are of such a nature as to protect the\\nparts within. They constitute the periderm, and are ordinarily cork-like,\\nhe., thin-walled and impervious to water. Those cells which lie outside\\nFig. 54 A. diagram of primary structure B, C, diagrams showing the results of\\nsecondary thickening from the stelar cambium in the two extreme forms c, cortex\\nen, its innermost layer; outermost layer of stele; /i primary bast f h sec-\\nondary bast x primary wood x x secondary w ood cl stelar cambium r, sec-\\nondary pith-rays m, pith.\u00e2\u0080\u0094 After Van Tieghem\\na layer of cork are therefore cut off from a supply of food and soon\\nperish.\\nThe inner growing layer, or stelar cambium, is developed within the\\nstele and follows a tortuous course, lying outside the wood strands and\\ninside the bast strands (fig. 54). As a result of tangential divisions in\\nthis region, tissues similar to those already existing in the stele are pro-\\nduced.\\nThe relative amount of the new tissues goes far to deter-\\nmine the character of the mature root.\\n79. (a) Woody roots. If mechanical tissues predomi-\\nnate, the root will become strong and rigid, as in the case of\\ntrees and shrubs. When the root is long-lived, the forma-\\ntion of new tissues is usually resumed with each season, and\\nthe central part, especially, shows in cross-section concentric\\nrings indicating the yearly additions. As the root thickens", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0072.jp2"}, "73": {"fulltext": "7 HE ROOT. 67\\nthe outside parts become fissured lengthwise. Thus, in an\\nold and large root of the woody type, all the parts outside the\\ncentral wood constitute a bark, which becomes furrowed\\nlengthwise, like the bark of the stems of many trees. Such\\nsecondary thickening finally produces in the roots a structure\\nwhich is almost identical with that of stems which have under-\\ngone secondary thickening. (Compare ^f m.)\\n80. (b) Fleshy roots. But if thin-walled cells are the\\nchief products, the root often becomes very thick and fleshy,\\nas in the carrot, turnip, radish, sweet potato, beet, dahlia,\\nartichoke, etc. Such roots serve the plant as storehouses of\\nreserve food, and are consequently useful to animals as food.\\nThis thickening for storage purposes may affect either the\\nprimary or secondary roots, or both.\\n81. (c) Float roots. Plants which grow in water or in\\nvery wet swamps sometimes modify their roots to serve as\\nfloats. In these cases, the voluminous cortex consists of large\\ncells, with huge intercellular spaces which are filled with air.\\nThe root thus serves to buoy up the parts of the plant to\\nwhich it is attached, and assist in its respiration. (See *j\\n202.)\\n82. (d) Tendrils, thorns, etc. In a very few plants,\\naerial roots are modified into tendrils, being slender, sensitive\\nto contact, clasping the objects which they touch, if of suit-\\nable size, and thus assisting the plant to climb; in some in-\\nstances they are altered into thorns, being short, rigid, and\\nsharp-pointed in others, being exposed to the light, they\\ndevelop chloroplasts, which enables them to act as organs for\\nthe manufacture of food.\\n83. Branching. Both primary and secondary roots may\\nbranch. The mode of branching is commonly monopodial,\\ni.e., the central axis grows most vigorously, and bears lateral\\nbranches upon its sides. The normal branches arise from\\nlateral growing points, which originate in regular succession", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0073.jp2"}, "74": {"fulltext": "68\\nOUTLINES OF PLANT LIFE.\\nbehind the apical growing point. But\\nsometimes branches appear out of this\\nregular order. Such are called ad-\\nventitious roots. (See ^[70.)\\nBranches generally originate oppo-\\nsite the wood strands, or with definite\\nrelation to them. (See figs. 55, 56.)\\nThe number of vertical ranks of bran-\\nches can, therefore, be predicted with\\nsome certainty from the structure of\\nthe root, but the longitudinal intervals\\nat which the branches will be formed\\ncannot, because they are unequal (fig.\\n55)-\\nWhen secondary roots arise from\\nthe shoot, they have a fixed relation\\nto the leaves, or they are formed upon\\nthe buds produced in the axils of the\\nleaves, or they may arise at indefinite\\npoints along the internodes. In the\\nfirst case, roots may be produced\\neither opposite a leaf, or in pairs, right\\nand left of the base of the leaf.\\n84. Origin. The origin of root-\\nbranches and of secondary roots is\\nrarely external that is, the root is\\nnot commonly produced by growth at\\nthe surface of a member. In the great\\nmajority of cases the origin of the\\nroots is internal that is, the forma-\\ntion of the root is begun by the growth\\nFig 5 s.-Seediing pea. showing in the interior of the member pro-\\nSK^JS^Si ducing it. In most cases growth\\nsYz^-Ahe rlvank 3 Natural begins very near to the surface of the", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0074.jp2"}, "75": {"fulltext": "THE ROOT.\\n6 9\\nstele. Soon a growing point is formed (fig. 56). The rootlet\\nis thus in its early stage completely hidden, being buried\\nbeneath the cortex, through which it gradually makes its way,\\npartly by disorganizing the tissues by pressure, and, probably,\\nFig. 56. Fig. 57\\nFig. 56. Transverse section of a root of a fern {Pier is cretica), passing through a\\nrootlet which has not yet emerged Only the stele and three rows of cortex shown.\\na, apical cell of rootlet, forming anteriorly the root-cap, e/ and posteriorly the body\\nof the root, ec, e, c, ftd; b, wood strands bast strand with its fellow opposite pe,\\nouter layer of stele en, inner layer of cortex p, cells partly disorganized and\\ndigested d, cells of cortex, which will be disorganized as rootlet advances. Highly\\nmagnified After Van Tieghem.\\nFig. 57. The same as fig. 56, but older not quite so much magnified. The rootlet\\nis just emerging from the parent root, pd, c, stele of the rootlet ec, its cortex; d,\\ndisorganized cells of cortex ec of parent root b secondary wood other letters as\\nin fig. 56. After Van Tieghem.\\npartly by actually digesting and absorbing the material of\\nthese cells. When the rootlet reaches the surface it emerges,\\ntherefore, from a distinct rift in the cortex (fig. 57).\\n85. Buds. New shoots may be formed by the roots, either\\nas a result of injuries, or normally. In a partially developed\\nform, these constitute buds (see ^j 91). Whether formed as", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0075.jp2"}, "76": {"fulltext": "/O OUTLINES OF PLANT LIFE.\\na result of injuries or normally, they are known as adventitious\\nbuds.\\nThey arise in the same places and develop in the same way as lateral\\nroots that is, they are internal in origin, and, as they continue to grow,\\nburst through the cortex. The shoots so produced grow in the normal\\nmanner. Very rarely the growing point of the root, casting off the root-\\ncap, becomes itself the growing point of the shoot. This alteration is\\nusually the result of artificial reversal of the position of the root, being\\nbrought about in some potted plants by being turned upside down.\\nEXERCISE XVI.\\nRoots. Germinate seeds of wheat, corn, white (or any) bean, pea, and\\nwhite mustard in clean damp pine sawdust or chopped peat moss.\\nObserve the form and distribution of the root-hairs on younger parts\\nof the root. Let wheat grow for several weeks and observe on what part\\nof the roots the root-hairs are dying away. 73.)\\nObserve arrangement and origin of branches in the roots of pea seed-\\nlings. (1T1F 83, 84, fig. 55.)\\nGrow wheat in soil, planting it about one inch deep. After two to\\nfour weeks examine roots, washing away sand carefully. Distinguish\\nprimary and secondary roots. (^J^[ 70, 77.)\\nObserve roots of sweet potato, beet, or dahlia, thickened for storage.\\n(IT 80.)\\nExamine a smoothly cut end of a root (as thick as one s finger) of any\\ntree (maple, oak, elm, etc.). Observe the bark the wood with concen-\\ntric layers (annual rings). r 79.) Compare with the stem of same tree.\\nContrast with structure of a root of lily or marsh marigold.\\nExamine the root of a lily, or marsh marigold, by cutting cross-sec-\\ntions and by dissection. Observe (a) the central stele, {b) the cortex.\\n86. Summary. True roots are found only in fernworts\\nand seed plants. Primary roots are usually transient second-\\nary roots may be transient or permanent. Both grow at the\\ntip only, which is protected by the root cap. The young parts\\nform numerous root-hairs, which are sloughed off after a short\\ntime (a few days or weeks) with the outer surface. The cen-\\ntral stele is chiefly for conduction of water and foods in young", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0076.jp2"}, "77": {"fulltext": "THE ROOT. 71\\nroots. In older roots these functions may be maintained\\nwith the addition of mechanical tissues for strength and cork\\ntissues outside for protection. Other roots as they grow older\\nmay be transformed into storage places, floats, tendrils, thorns,\\netc. The branching of roots is usually monopodial. Branches\\narise in longitudinal rows, originating internally near the\\nsurface of the stele. Roots may produce adventitious buds\\ninstead of root branches.", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0077.jp2"}, "78": {"fulltext": "CHAPTER IX.\\nTH E SHOOT.\\n87. Primary shoot. The first shoot which develops is\\ncalled the primary shoot. Rarely no primary shoot develops.\\nSometimes the primary shoot early ceases to grow, and its\\nplace is taken by secondary shoots arising from the root.\\nThe tip of the shoot is the region in which the formation\\nof new cells is taking place. This region of young cells has\\nno definite limit below, but passes insensibly into the older,\\nwhich it produces. The tip of the shoot may be either a\\nsharp cone or a low dome. Between these forms a complete\\nseries of gradations exists. Close below the apex the shoot\\nbegins to show a differentiation into a central axis and lateral\\noutgrowths. The first of these to appear are swellings which\\nform the leaves. Later, above the leaf rudiments, the rudi-\\nments of the lateral shoots may appear. The older leaves upon\\nthe sides of the axis outgrow the younger ones and the de-\\nveloping axis, and arch over them in such a way as to form\\na more or less compact structure, which is a terminal bud. A\\nbud is, then, an undeveloped shoot, whose older leaves pro-\\ntect the younger, and particularly the youngest region, the\\napex (fig. 58). From the terminal bud arise all the mem-\\nbers of the primary shoot.\\n88. Differences from root. From what has been said of the origin of\\nthe shoot, it will be observed that it is distinguished from the root by not\\nforming in front of the apex a protecting cap. In further contrast with\\nthe root, the shoot possesses an uninterrupted epidermis over its entire\\n72", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0078.jp2"}, "79": {"fulltext": "THE SHOOT.\\nn\\nsurface, consisting always at first of a single layer of cells. This epider-\\nmis persist^ as a surface covering either throughout the life of the shoot.\\nor for a long period, being replaced only upon the older surfaces of the\\nstem by subsequently formed protective layers. (See III.)\\nFig. 58.\u00e2\u0080\u0094 Diagram of a section through a bud. V, the apex 1, 2, 3, 4, successively older\\nleaf rudiments a, b, c, successively older branch rudiments d, e, vascular bundles.\\nAfter Hansen.\\n89. Branching. Branches of the shoot arise from lateral\\nbuds, which are in all respects like the terminal buds just de-\\nscribed. If, for any reason, the terminal bud of the stem is\\ndestroyed, or its growth arrested, a branch, developing from\\na lateral bud near by, may assume the position and habit of\\nthe main axis. In many plants the death or arrest of the\\nterminal bud recurs at regular intervals. In such plants,\\ntherefore, the main axis is really a succession of lateral\\nbranches, i.e., the branching is sympodial (cf. fig. 59 and\\n^[58). In some plants, e.g., lilac, two lateral buds standing\\nat the same level may develop, if the terminal one fails. In\\nthis case the shoot divides into two equal branches. Ordi-\\nnarily, however, the terminal bud develops without interrup-\\ntion. In case it is more vigorous than any of the lateral", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0079.jp2"}, "80": {"fulltext": "74\\nOUTLINES OF PLANT LIFE.\\nbuds, the plant will have a central axis, from the sides of\\nwhich distinctly smaller branches arise. If, however, the\\nlateral buds are almost or quite as strong as the central one,\\nthe plant seems to be broken up into branches, and, after it\\nhas attained its mature form, no one can\\nbe pointed out as the main axis.* Such\\nbranching is monopodia! (see ^j 58).\\nThese two types of monopodial branch-\\ning and the sympodial type are all illus-\\ntrated in the forms attained by common\\nforest trees. (See frontispiece.)\\n90. Inflorescence. Especially profuse\\nbranching commonly occurs in the parts\\nof the seed plants where flowers are pro-\\nduced. Such clusters of branches bearing\\nflowers constitute an inflorescence. Each\\nsort has received a special name which\\nindicates the type of branching, and also\\nthe relative length of the branches, f\\n91. Lateral buds. Lateral buds are\\nordinarily formed in definite relation to\\nthe leaves. They stand usually in the\\nupper angle formed by the leaf with the\\nstem. This angle is the axil of the leaf,\\nand such buds are said to be axillary\\n(fig. 60). Ordinarily a single bud arises\\nin the axil of each leaf. Its origin is\\nalways later than that of the leaf-rudi-\\nment (fig. 58).\\nThere are many cases in which the lateral buds are not\\nFig. 59.\u00e2\u0080\u0094 Shoot of Euro-\\npean linden, t, the last\\ninternode formed by the\\nbud of present season.\\nThis dies and drops off\\nand the shoot will be\\nformed next year by the\\nlast auxiliary bud, a,\\nwhich appears to be ter-\\nminal after loss of t.\\nHalf natural size \u00e2\u0080\u0094Af-\\nter Frank.\\nThe obscurity is greatly increased by the death of more branches than\\nsurvive, owing to various causes resulting in poor nutrition or disease.\\nf For these names and further discussion see Gray: Structural Bot-\\nany, p. 144; Goebel: Outlines of Classification, p. 407.", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0080.jp2"}, "81": {"fulltext": "THE SHOOT.\\n75\\nfound precisely in the axils of the leaves, but slightly to one\\nside, or at a greater or less distance above the axil (figs. 61,\\nFig. 60.\\nFig. 60.\u00e2\u0080\u0094 I, terminal shoot of an elm. b, leaf-\\nscars k, axillary buds. Natural size. II,\\none of the buds cut lengthwise through\\ncenter, magnified 3 diam. a, young axis;\\nb, leaf-scar bl, young leaves d, bud-\\nscales. After Behrens.\\nFig. 61. A, twig of red maple with ac-\\ncessory buds in addition to axillary bud.\\nB, twig of butternut, with leaf-scar, a, small\\naxillary bud, b, and larger accessory buds,\\nc, d, above axil. Natural size. After\\nGray.\\nFig 62. A bit of stem of a honeysuckle\\n(Lonicera xylosteum} bearing large axillary\\nand smaller superposed accessory buds above\\nthe axils of the scars, ww, from which\\nleaves have fallen. Natural size. After\\nFrank.\\nFig. 62.\\n62). Buds are frequently formed without any relation what,\\never to the leaf-axil, and even on the leaf itself (fig. 179).\\nSometimes these extra-axillary buds are produced without the", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0081.jp2"}, "82": {"fulltext": "j6 OUTLINES OF PLANT LIFE.\\naction of any extraordinary cause, but more commonly injury\\nof one sort or another acts as a stimulus to the production of\\nsuch buds. Buds which do not originate in regular succes-\\nsion on the parent shoot (i.e., the younger nearer the apex)\\nare called adventitious buds.\\nAdventitious buds may arise upon stems, leaves, or roots.\\nThey are most commonly and abundantly produced upon\\nstems and roots.\\n92. Dormant buds. Many buds continue to grow without\\ninterruption from the time of their formation, but more cease\\nto develop after they have reached a certain stage. Such\\nbuds may remain dormant for a considerable period, and\\nmay even be overgrown and completely enclosed by the\\nwood upon old shoots. The bud in this case grows slowly\\nand maintains itself near the surface of the wood. It is quite\\npossible that these dormant buds should for some reason\\nbegin to develop later, when they are liable to be confounded\\nw r ith adventitious buds.\\nIn case they have been buried by the growth of tissues over them, the\\nshoots which they produce will seem to come from the interior of the\\norgan upon which they are borne. This apparent internal origin must\\nnot be confounded with the real internal origin of roots.\\nSince in most cases lateral buds have a definite relation to\\nthe leaves, the shoots which arise from them will have a\\nsimilar relation. But, as many buds are produced which\\nnever develop into branches, this relation is often obscure\\nand difficult to see.\\n93. Special forms. The primary shoot may grow under-\\nground, in which case its stem usually takes a horizontal\\ndirection and becomes much thickened for storage of reserve\\nfood fl[ 196), while its leaves are so reduced as to be scarcely\\nrecognizable. Such a shoot is a rhizome. When the primary\\nstem is short, erect, and crowded with thickened leaf bases it\\nforms a bulb, as in the hyacinth and onion. When the", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0082.jp2"}, "83": {"fulltext": "THE SHOOT. 77\\nprimary stem is short and thick, and has thin scale leaves\\nupon it, it forms a conn, as in cyclamen and Indian turnip.\\nBranches of the specialized primary shoot may be like it,\\nas when some branches of the rhizome or conn are them-\\nselves rhizomes or conns. Others, however, will be adapted\\nto other purposes, as when aerial branches arise from rhizomes\\nto carry foliage and flowers, or when slender leafless shoots\\ncalled runners develop from the main axis of the strawberry\\n(fig. 183). Offsets and stolons (figs. 182, 207) are similar\\nbranches likewise adapted to propagation. (See ^f 301.)\\nBranches of the secondary shoots may also be different\\nfrom their parent axis. In different plants the shoots assume\\nthe most varied forms.\\nSuch specialized branches may be confined to a definite\\nregion of the plant, or may be distributed over it. The\\nmore important of these kinds of branches may now be\\nenumerated.\\n94. (a) Dwarf branches. It is not uncommon to find\\nbranches specialized merely by their slight development in\\nlength and their capacity for being separated readily from\\nthe parent shoot. Such short branches are particularly com-\\nmon among the cone-bearing trees. In these plants the\\nshort branches carry the clusters of needle leaves (figs. 63,\\n64, 198). After the death of the leaves the branches them-\\nselves drop off. Somewhat similar short branches are to be\\nrecognized among many deciduous trees, and, in the apple,\\nthe so-called fruit spurs are not dissimilar (fig. 65).\\n95. (5) Flowers. The most common of the specialized\\nbranches among the seed plants are those which constitute\\nthe flower. In these the axis usually remains short, the\\nleaves are crowded, and often some of them are highly\\ncolored (fig. 66). Commonly these flower branches are\\nshort-lived and drop off with the fruit or earlier.\\n96. (c) Leaf-like branches. A few plants have developed", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0083.jp2"}, "84": {"fulltext": "78\\nOUTLINES OF PLANT LIFE.\\nFig. 63. Fig. 65.\\nFig. 63. -A shoot of Scotch pine showing two regions of dwarf branches each with a\\npair of needle leaves, and three regions of flower branches; the flowers have fallen\\nfrom lower two, showing scale leaves covering the stem. Natural size. After Will-\\nkomm.\\nFig. 64.\u00e2\u0080\u0094 The base of leaves and dwarf branch of Scotch pine cut through the center\\nlengthwise. Besides the two needle leaves the dwarf branch carries a number of\\nscale leaves, d. Between the bases of the needle leaves is seen the conical apex of the\\ndwarf branch, showing their lateral origin. Magnified about 4 diam. After Luerssen.\\nFig. 65.\u00e2\u0080\u0094 Twig of apple, bearing fruit spurs. A, points at which fruit was detached\\nthe preceding year; leaf scars. Natural size.- After Hardy.", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0084.jp2"}, "85": {"fulltext": "THE SHOOT.\\n79\\nshoots which replace leaves in function and resemble them\\nin form. These branches may be either broad and flattened,\\nas in the smilax of the greenhouses, or they may be slen-\\nder and needle-like, as in the common garden asparagus\\n(fig. 67). In any case, since they replace leaves in function,\\nFig. 66. Fig. 67.\\nFig. 66.\u00e2\u0080\u0094 Flower of Sedum acre, s, sepal; petal; st, stamen; c, carpel. Magni-\\nfied 3 diam.- -After Baillon.\\nFig. 67. Piece of a twig of asparagus; in the axil of the scale leaf, b, arise a flower\\nshoot, and three leafless needle-like branchlets. Magnified about 2 diam. After\\nFrank.\\nthey are abundantly supplied with green coloring matter for\\nmanufacturing food.\\n97. (d) Bulblets. Other branches remain undeveloped\\nas buds, but their leaves become thick and fleshy. These\\nbulblets are easily detached and serve for propagation. (See\\nT 299.) They are to be found in many plants. In the\\ntiger-lily they occupy the axils of the leaves (fig. 180), and\\nare modified lateral buds, while in the garden onion they\\nusually replace the flowers.\\n98. (e) Tubers. Some underground shoots have their\\nends suddenly and greatly enlarged, adapting them to the\\nstorage of food. They are then called tubers. In the white\\npotato the tuber consists of several terminal internodes of\\nan elsewhere slender underground stem, the eyes being\\nlateral buds in the axils of minute scale leaves. In a few\\nplants tubers may even be formed above ground, as in certain\\npolygonums whose flowers are often replaced by little tubers\\nwhich are readily detached (fig. 68).", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0085.jp2"}, "86": {"fulltext": "8o\\nOUTLINES OF PLANT LIFE.\\n99. Tendrils. Some shoots take the form of slender,\\nleafless, sensitive tendrils, which assist the plant in climbing\\nby coiling about suitable objects\\n(fig. 69).\\n100. (g) Thorns. Many\\nplants produce defensive shoots,\\nwhich are leafless, rigid, short,\\nand sharp, called thorns, which\\nFig. 68. Fig. 69.\\nFig. 68. ,4, upper part of a plant of Polygonum viviparum, showing flower cluster,\\nthe flowers in lower half being replaced by tubers. Two-thirds natural size. B, a\\nfallen tuber. Magnified about 3 diam. C, a plantlet growing from tuber. Natural\\nsize. After Kerner.\\nFig. 69. A portion of the stem of white bryony, B, from which a tendril, u.r, arises\\nnear the leaf stalk, b, and the bud, k. tt, rigid portion of tendril the portion between\\nu and the portion x, clasping the support, A has become coiled into a spiral which\\nreverses the direction of the coils at iv and w Nearly natural size.\u00e2\u0080\u0094 After Sachs.\\nmay be either simple or branched (fig. 70). The honey-\\nlocust furnishes an excellent example of branched, or com-\\npound, thorns.", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0086.jp2"}, "87": {"fulltext": "THE SHOOT.\\n81\\nLeaves themselves may be developed as tendrils or as thorns, so that\\nit must not be assumed from appearance alone that such members are\\nforms of the shoot. Observation of the origin and relation of the mem-\\nbers will reveal their true nature. If shoots, they will usually be sub-\\ntended by a leaf if leaves, they will often have a bud or a shoot in their\\naxils. Thorns or tendrils which do not arise at the nodes are reckoned\\nas shoots.\\n101. Duration. Shoots are either annual, biennial, or\\nperennial. If the entire shoot dies this generally involves\\nthe death of the whole plant, though new adventitious shoots\\nFig. 70.\u00e2\u0080\u0094 Shoots of Vella spinosa, showing thorns. Natural size. After Kerner.\\nmay arise from the roots, as in sweet potatoes. In many\\nplants, in which the shoot seems to die at the close of the\\ngrowing season, an underground portion really survives, and\\nsends up the new shoots. Such plants, if they live for two\\nyears, are called biennials or, if they live for several or\\nmany years, are called perennials.\\nThe shoot may be composed mainly of soft tissues, and\\npersist underground, where it is protected against unfavorable\\nconditions, such as drought and cold, and especially against", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0087.jp2"}, "88": {"fulltext": "82 OUTLINES OF PLANT LIFE.\\nsudden changes or it may be composed mainly of mechan-\\nical tissues, and be fully exposed, as are the shoots of trees.\\nIn these cases the leaves generally perish and drop off an-\\nnually, but in the evergreen plants they live more than\\none growing season.\\nEXERCISE XVII.\\nShoots. Examine the shoots of the linden, elm, maple, oak, and lilac\\nand observe the mode of branching, and the arrangement of the buds.\\n(IT 89).\\nStudy the construction of winter buds of lilac, horsechestnut, or hick-\\nory. (This can be done most easily by examining them just as buds are\\nunfolding in spring, or by keeping shoots in a warm room for a few days,\\nwhen the buds will begin to open.) Observe the form and arrangement\\nof the scales and the way in which foliage leaves are folded. How are\\nthese buds protected against water Against sudden changes of temper-\\nature? HI 87, 133.)\\nExamine the rhizomes of couch grass, mint, Solomon s seal or blood-\\nroot; the bulb of the onion or hyacinth; the tuber of the white potato,\\nas forms of underground storage shoots 93, 98). Do these shoots\\nhave buds on them\\nExamine the tendrils of the passion flower (or the wild cucumber vine);\\nthe thorns of the haws or the honey locust, as special leafless forms of the\\nshoot.\\n102. Summary. The shoot grows at the tip, new lateral\\nmembers being formed in regular succession below it. These\\nyoung members and the tender tip itself, protected by some\\nolder leaves, compose the terminal bud. Similar growing\\npoints arise on the sides of the main shoot and exist for a\\ntime as lateral buds. Some buds die, and some live but re-\\nmain undeveloped. Others develop into branches similar to\\nor different from the main axis. Special forms of the shoot\\nare produced to serve special purposes, such as storage,\\nreproduction, protection, climbing, etc. The branches,\\nsome or all, and even the main shoot, die after a time. An-\\nnual shoots die after one growing season, biennial shoots\\nafter two, and perennial shoots after several or many.", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0088.jp2"}, "89": {"fulltext": "CHAPTER X.\\nTHE STEM.\\n103. Definition. The shoot is almost always segmented\\ninto members of two kinds, the stem and leaves. The stem\\nis the central axis of any shoot, and the leaves are lateral\\noutgrowths, or branches, of it. These two members cannot\\nbe accurately defined, but are in most cases readily recog-\\nnized. Leaves commonly differ from the stem in their\\nflattened form, limited growth, and position, subtending the\\nlateral shoots. (See further p. 96.)\\n104. Nodes and internodes. Upon examining the surface\\nof the stem, it is almost always readily distinguishable into\\ndistinct regions, the nodes and internodes. The nodes are\\nthe narrow zones, often somewhat swollen (whence the\\nname), at which one or more leaves arise. The internodes\\nare the zones between the nodes. Upon watching the de-\\nvelopment of the stem from the terminal bud, it will be\\nseen that new nodes and internodes are constantly emerging\\nfrom its base, and that the leaves formed at the nodes are\\nsuccessively expanding. This emergence of the internodes\\nis due to their growth. The amount of growth, however,\\nvaries greatly in different plants, and even in different parts\\nof the same plant. In many cases the internodes are con-\\nsiderably and uniformly elongated; the leaves are then dis-\\ntributed along the stem at considerable and regular intervals.\\nIn other cases the internodes remain very short, and the\\nleaves are, therefore, crowded. They may be so crowded as\\n83", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0089.jp2"}, "90": {"fulltext": "84 OUTLINES OF PLANT LIFE.\\nto envelop the stem completely and hide it from view. This\\nis well seen in the scale-like leaves of such plants as the pines\\n(fig. 63), cedars, and arbor vitae\\n(fig. 71). Or, certain of the\\ninternodes may elongate, while\\nothers remain undeveloped.\\nFor example, in the shepherd s-\\npurse, the first internodes re-\\nmain short, so that the lower\\nleaves are crowded into a tuft\\nor rosette; the following inter-\\nnodes are elongated, the corre-\\nsponding leaves being scattered\\nFig. 71. A shoot of arbor vitae or white 1 1 V, 1\\ncedar, showing scale leaves covering at regular intervals; Wnlle,\\nstem. Natural size.-After Kerner. stiU higher the internodes are\\nagain shortened and the leaves brought into close clusters in\\nthe flowers.\\n105. A section of the stem commonly presents an irregularly circular\\noutline (fig. 72). Occasionally the surface of the stem is fluted or chan-\\nneled, and, if these grooves or channels be few, and the corresponding\\nangles prominent, the section of the stem is polygonal, with three, four,\\nfive, six, or more sides (fig. 131).\\n106. Habit. As to habit, stems are commonly erect\\nwhen enough mechanical tissue is developed to render them\\nsufficiently rigid to carry not only their own weight, but that\\nof the leaves and other members attached to them. Other\\nstems lie flat upon the ground, to which they may or may\\nnot attach themselves by the development of secondary roots.\\nBetween these prostrate, or creeping, stems and the erect form\\nevery conceivable position exists. The direction of growth\\nis determined largely by the relation of the plant to gravity\\nand light as stimuli. (See ^f^f 243, 245.) Other stems rise\\ninto the air, not by their own rigidity, but by the develop-\\nment of special members for climbing purposes, such as", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0090.jp2"}, "91": {"fulltext": "THE STEM.\\n35\\nrecurved spines, tendrils, sensitive Leaf stalks, or even by\\nrecurved normal branches. (See 99, 131.) Others wrap\\nthemselves about objects of suitable size, and are called\\ntwining steins. (See 249.)\\n107. Primary structure. If a thin section be cut from\\nan internode which has just reached its full length, three\\ndefinite regions maybe distinguished, viz. (1) the epidermis;\\n(2) the cortex; (3) the stele (figs. 72, 73).\\n1. The epidermis is a single layer of cells forming the\\nextreme edge of the section, being, therefore, the layer which\\nFig. 72. Fig. 73-\\nFig. 72. Diagram of a transverse section of stem of Iberis amara, showing outline,\\nand paired vascular strands. The black is the wood strand the gray is the bast\\nstrand. The outer line represents the epidermis a circle including the bundles would\\nmark the limits of the stele, with its central pifh the cortex lies between the epidermis\\nand stele. After Nageli.\\nFig. 73.\u00e2\u0080\u0094 Diagram of a transverse section of a palm stem. The epidermis is represented\\nby the outer line the narrow cortex lies between this and the inner circle the stele,\\nwith numerous bundles scattered through the pith, is within the cortex. After\\nFrank.\\ncovers the surface of the stem. Here and there are minute\\nopenings which permit communication between the outside\\nair and spaces between the cells of the cortex. These open-\\nings are usually bordered by two specialized cells, and are\\ncalled stomata. (See *|f 137.) Naturally they are wanting\\nm submerged stems of water plants and in most subterranean\\nstems. The epidermis is often furnished with hairs, scales,\\nand like outgrowths (figs. 74, 75, 200-203).", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0091.jp2"}, "92": {"fulltext": "86\\nOUTLINES OF PLANT LIFE.\\n2. The cortex consists of several layers of cells, usually\\nthin-walled and not in close contact, and hence abundantly\\nprovided with intercellular spaces. These cells usually con-\\ntain many chloroplasts, to which the green color common to\\nyoung stems is due.\\n3. The stele forms the central region. Its most striking\\nparts are several or many clusters of smaller cells, the cut ends\\nof the vascular strands. Occupying the space between the\\nvascular strands is the pith (figs. 72, 73).\\n108. The cortex. In certain plants the cortex undergoes\\nan enormous development, forming in some tubers the\\ngreater part of the massive stem;\\nin others it is so reduced that it\\nconsists only of two or three layers\\nof cells. With the epidermis it\\nvery commonly enters into the for-\\nmation of outgrowths, such as\\nFig. 74. Fig. 75.\\nFig. 74.\u00e2\u0080\u0094 Forms of hairs from Plectranthus. a, simple pointed hair b, stalked\\nglandular hair c, sessile glandular hair with secretion covering the two glandular\\ncells. Highly magnified. After De Rary.\\nFig. 75. T-shaped hair of the wall-flower (Cheiranthus). e, epidermis. Highly\\nmagnified.\u00e2\u0080\u0094 After De Bary.\\nwarts, prickles, wings, etc. Very frequently the intercellular\\nspaces of the cortex are greatly enlarged, forming air passages\\nof considerable size (fig. 76). In other cases the cortical\\ncells, instead of remaining thin-walled, may become greatly\\nthickened in certain regions, or even throughout the cortex.\\nThese mechanical cells are likely to be aggregated in clusters\\nor strands, and serve an important purpose in strengthening\\nthe stem.", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0092.jp2"}, "93": {"fulltext": "THE STEM. 87\\n109. Stele. The outermost part of the stele often pro-\\nduces mechanical cells with thick walls and small cavities.\\nThey are either aggregated in strands opposite to the vascular\\nstrands of the stele, or they constitute a complete zone\\nFig. 76. Transverse section of the stem of Elatine, showing intercellular canals, C.\\nMagnified about 15 diam.\u00e2\u0080\u0094 After Reinke.\\naround it. Many of the most valuable textile fibers, such as\\nthose of flax, hemp, and ramie, are obtained from this region\\nof the stem (fig. 77).\\nIn any section of the stem the number of vascular strands\\nin the central cylinder varies greatly, not only in different\\nplants, but even in different parts of the same plant. The\\nstrands are commonly arranged in pairs, a bast strand and a\\nwood strand being placed side by side, the former occupying\\nthe side next the surface of the stem, and the latter the side\\nnext the center (figs. 72, 78). The number and position of\\nthese bundles is, however, subject to change. In some\\ncases one of the strands surrounds the other. Commonly\\nit is the bast which surrounds the wood, as m the fernworts.\\nSometimes independent bast strands are found with which\\nare associated no wood strands. In the bast certain cells", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0093.jp2"}, "94": {"fulltext": "88 OUTLINES OF PLANT LIFE.\\nmay develop into fibers, which are quite like the fibers\\nFig. 77,-Portion of a transverse section of the stem of flax, m, pith h, secondary\\nwood forming a cylinder ph, bast 6, strands of mechanical tissue (fibers) among\\nthe thin-vvalled cells, the two sorts making up the cortex the epidermis. Magni-\\nfied about 25 diam.\u00e2\u0080\u0094 After Frank.\\nFig. 78.\u00e2\u0080\u0094 Transverse section of a bundle pair from the stem of a begonia. Th.\\npart is the wood strand; the small irregular cells above are the bfst strand between\\nhem is a zone of growing cells the stelar cambium, which extends also right and\\nleft of the bundle pair. The radius of the section passes through CP C next the\\ncenter. Magnified 150 diam.-After Haberlandt. S he\\noccurring in the outer part of the stele.\\nare valuable in the textile industries.\\nSome of these, also,", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0094.jp2"}, "95": {"fulltext": "THE STEM.\\n8 9\\nThe paired vascular strands within the stele occupy various positions,\\nand for purpose of location may be spoken of as though single. If trans-\\nverse sections of the stem are observed, they may be seen either in a sin-\\ngle row, roughly parallel with the surface of the stem (fig. 72), or in\\nseveral concentric rows (fig. 79), or they may be irregularly disposed\\nthroughout it (fig. 73). No one method of arrangement is confined to any\\nof the larger groups of plants, although the first is characteristic of most\\nsr\u00c2\u00bb\\nFig. 79. \u00e2\u0080\u0094Transverse section of the aerial stem of an onion (Allium Schoenopraswui).\\ne, epidermis ch, chlorophyll-bearing tissue of cortex; r, colorless tissue of cortex;\\ng, g vascular bundles (wood bundles black, bast bundles dotted); sr, mechanical\\ntissues connected into a cylinder; m, pith; h, pith canal formed by destruction of\\ncells. Magnified 30 diam.\u00e2\u0080\u0094 After Sachs.\\ndicotyledons, while both the second and third methods are common\\namong the monocotyledons. But so many exceptions are found to these\\nlast statements that it is best not to indicate the arrangement of the bun-\\ndles by the terms dicotyledonous or rnonocotyledonous, as has been com-\\nmonly done; nor is it possible to maintain the terms exogenous and en-\\ndogenous, which have long since become obsolete because misleading.\\n110. Pith. The pith is frequently found enormously\\ndeveloped in those parts of the stem used for storing reserve\\nfood, such as the tubers of the white potato and the yam. In\\nother plants, particularly those growing in water, it suffers", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0095.jp2"}, "96": {"fulltext": "9 o\\nOUTLINES OF PLANT LIFE.\\nextreme reduction or is often completely wanting, in which\\ncase the bundles of the stele are in close contact, and the\\ncortex usually shows a corresponding increase. In other\\nplants the cells constituting the pith are greatly thickened,\\nso as to form a mechanical tissue.\\nThe thickened areas are usually either opposite the vascular strands,\\nforming a strand closely adherent to their inner faces, or they may extend\\nto their flanks, thus forming an arc\\nembracing each. Sometimes the thick-\\nened region becomes extended between\\nthe vascular strands and joins other\\nmechanical tissues of the stele, or even\\nthose of the cortex, so as to enclose\\ncompletely the individual strands (fig.\\n80).\\nIn other plants the pith dies\\nearly and shrivels up. Very large\\ncanals may thus be formed\\nthrough it, or it may even disap-\\npear entirely (fig. 79). Such\\nFig. 80.\u00e2\u0080\u0094 Transverse section of a bundle _\\npair of Indian corn. bast bun- early disappearance ot the pith\\ndie; .r, g, g, s, r, wood bundle;\\npith; an intercellular space formed prOQUCeS the hollOW Stem cha-\\nby the tearing of some of the wood\\ntissues. The bundle pair is surrounded raCteriStlC Ot the graSSeS, the\\nby a sheath of thick-walled mechanical\\ntissues. Magnified 235 diam.\u00e2\u0080\u0094 After sedges, and various members of\\nSachs.\\nthe sunflower family.\\n111. Secondary structure. Some stems retain through-\\nout their entire existence the primary structure which has\\njust been described, undergoing only slight changes which\\ndo not materially alter the structure. This permanence of\\nprimary structure is frequent in the stems of monocotyledon-\\nous plants. But the stems of the great majority of dicoty-\\nledonous plants, as well as the conifers, quickly lose their\\nprimary structure, adding tissues of considerable amount, so\\nas to bring about a more or less striking rearrangement of\\nthe first formed tissues (fig. 81). This is due chiefly to the", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0096.jp2"}, "97": {"fulltext": "THE STEM.\\n91\\nformation of one or two layers of actively dividing cells,\\nroughly parallel to the surface. When there are two such\\nlayers they are concentric.\\nThey are formed from existing\\ncells which retain or resume\\ntheir power of active growth\\nand division. The develop-\\nment of the tissues from the\\nexternal growing layer, called\\nthe cork ca?nbium, results in the\\nformation of secondary cortex,\\ncalled periderm, while the\\ntissues arising from the in-\\nternal growing layer, or stelar\\ncambium, form the secondary\\nwood and secondary bast (fig.\\nso.\\n112. Cork. The outer tis-\\nsues of the periderm rarely\\nremain living. The close-set\\nflat cells early lose their con-\\ntents, and the walls become\\nwaterproof, forming cork (fig.\\n82). Other cells may be al-\\ntered into mechanical tissues by\\nthe thickening of their walls\\nand the death of the proto-\\nplasm. Zones Of Cork Often Fig. 81.\u00e2\u0080\u0094 Part of a transverse section of\\nalternate in the periderm with\\nzones of mechanical tissues.\\nSince almost no water can\\npass through a cork zone, it is\\nevident that all parts lying out-\\nside of one are cut off from a supply of nourishment, and must\\na young stem of cinchona in process of\\nsecondary thickening, tz, hairs epi-\\ndermis k, cork-cambium mr, cortex\\ns, gum-resin tubes in cortex sb, primary\\nbast strand c, stelar cambium g, h,\\nsecondary wood mk, pith rays m,\\npith The tissue between sb and c is\\nsecondary bast. Highly magnified.\\nAfter Tschirch.", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0097.jp2"}, "98": {"fulltext": "92 OUTLINES OF PLANT LIFE.\\ntherefore perish sooner or later. How much of the stem will\\nthus be killed depends upon the position of the layer of cells\\nwhich produces the cork.\\nAnnual shoots have usually but a small amount of periderm\\nformed, or sometimes none at all.\\nIn perennials, periderm is formed not\\nonly during the first year s growth,\\nbut the activity of the cork cambium\\nis resumed at the beginning of suc-\\nceeding seasons, so that annual addi-\\ntions are made to it.\\n113. Bark. The dead tissues\\nwhich accumulate from year to year\\nupon the outside of perennial stems\\nF s C ;cLr P of /oung tr stem er of constitute a large part of what is\\npeSn. ho t 1 ?p f rd r eTn5s n t known as the bark. The inner part\\nS[h o/e A rowof seTondT; of the bark belongs to the stele. (See\\nS .5S\u00c2\u00a3SLL^iBSi 1 7.) In the bark of most trees\\none or more cork-forming layers\\noriginate in addition to the first, giving rise thus to sheets\\nof cork either concentric with the first, or intersecting it\\n(fig- 83).\\nIn the first case the dead outer parts may peel off in con-\\ncentric sheets, as in the birch. In the second the dead parts\\nbreak away in the form of scales or flakes, as in the hickory,\\nsycamore, or apple. In many trees the dead outer portions\\nare only gradually worn away by the action of the weather,\\nbecoming seamed or deeply furrowed lengthwise.\\n114. Secondary wood and bast. The position of the in-\\nternal growing layer, the stelar cambium, is not subject to the\\nsame variations as the external one.\\nIn the many dicotyledons whose stems increase in\\ndiameter, the strands of wood and bast are in a single circle\\nparallel to the surface, the bast bundles in each pair being on", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0098.jp2"}, "99": {"fulltext": "THE STEM. 93\\nthe outside. The stelar cambium arises between the wood\\nand the bast strands of each pair, and extends across the\\npith rays which intervene, thus forming a complete zone\\nnearly concentric with the surface of the stem (figs. 78, 81,\\nFig. 83. Part of a transverse section of the bark of cinchona, c, layers of cork formed\\nby a transient cork cambium, s, thin-walled tissues, with occasional stone cells. The\\nsheets of cork cells are lines of weakness along which the flakes of bark split off.\\nMagnified 665 diam.\u00e2\u0080\u0094 After Warnecke.\\n84, A). On the inside of the cambium there arises, opposite\\nthe primary wood, secondary wood. Outside the cambium,\\nopposite the primary bast, there arises secondary bast. Each\\nstrand is thus increased in its radial thickness (fig. 81).\\n115. Pith rays. The cambium in the pith between the\\nbundles either produces pith tissue (B, fig. 84), or it forms\\nsecondary wood and bast corresponding to that produced\\nbetween the adjacent bundles. In the latter case, therefore,\\na complete zone or ring of secondary wood and bast is", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0099.jp2"}, "100": {"fulltext": "94\\nOUTLINES OF PLANT LIFE.\\nformed, so that the pith occupies the center. Upon the ring\\nof secondary wood thus produced the primary wood strand\\nprojects into the pith, and upon the ring of secondary bast\\nthe primary bast strand projects into the cortex (C, fig. 84).\\nIntermediate between these two methods, it is common to\\nhave new strands produced by the cambium formed in the\\npith rays, these strands remaining separated by narrower pith\\nrays {D, fig. 84).\\nFig. 84. Diagrams of transverse sections of stems illustrating modes of secondary\\nthickening. In all c, cortex; en, its inner boundary; limit of stele /i primary\\nbast; secondary bast; cb, stelar cambium; x primary wood; .v secondary\\nwood; r primary pith rays; r secondary pith rays.\u00e2\u0080\u0094 After VanTieghem.\\nThe secondary strands thus formed can, of course, have\\nno direct connection with those which enter the leaves. In\\nthis they differ from the primary strands, branches from\\nwhich enter each leaf. (See ^f 136.)\\n116. Annual rings. If the stem is perennial, year after\\nyear the stelar cambium resumes its growth, adding layer\\nafter layer to the secondary wood and bast. Thus most trees\\nhave their shaft-like trunks formed. The cambium forms a\\nline of weakness, and the parts outside separate readily from\\nthe wood. They constitute the bark.\\n117. The bark. As has been already shown (^f 113) the\\nouter part of the bark consists of the dead, dry, shriveled\\nparts of the periderm lying outside the cork cambium. The\\ninner portions of the bark are composed of the tissues which", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0100.jp2"}, "101": {"fulltext": "THE STEM. 95\\nlie between the cork cambium and stelar cambium. This\\ninner part contains a greater amount of water than the outer,\\nand always some living tissues. It may consist of a part of\\nthe cortex and both primary and secondary bast. As the\\ntree grows older the bark may come to consist almost wholly\\nof secondary bast. It attains considerable thickness only\\nwhen the loss from weathering is slow.\\nEXERCISE XVIII.\\nStems. Cut cross-sections of the stem of (i) a seedling beam and (2)\\na young stem of asparagus and compare. Observe in (1) the three\\nregions, epidermis, cortex, and stele 107). In the stele observe (a)\\nthe cut ends of the vascular strands and their arrangement. (Each pair\\nlooks like a single strand except in very thin sections.) (b) The central\\npith. In (2) observe the epidermis, very narrow cortex, and the stele\\noccupying the greater part of the section. In the latter observe the cut\\nends of the strands, distributed throughout the pith.\\nCut a cross-section of the three-year-old shoot of any shrub or tree.\\nObserve (a) the central pith, {b) the wood strands increased in number\\nand thickness until they form a cylinder of wood, in which three annual\\nlayers can be observed (how marked?); (c) the stelar cambium, a line of\\nweakness (young cells) outside the wood; (d) the bark, composed of the\\nbast strands on the inside, the cortex (in part) next, and the periderm\\n(brown) on the outside. Compare with the bean stem, How much is\\nthe stele? fl[f Hi-\u00c2\u00ab7.)\\n118. Summary. The stem shows nodes, i.e., the zones of\\nattachment of leaves, and internodes. The length of the\\nlatter determines the distribution of the leaves. Stems may\\nbe erect, prostrate, or climbing. They show three regions,\\nepidermis, cortex, and stele; each with great variety of struc-\\nture in different plants. The stele consists of vascular strands\\nof two kinds, arranged in pairs, and embedded in pith. As\\nstems grow older they frequently increase in diameter by the\\nformation of concentric growing zones in the cortex and\\nstele. The outer one produces the periderm, the inner one\\nwood and bast. In trees and shrubs the wood and bast\\nreceive annual additions. They separate readily at the stelar\\ncambium, the outer cylinder being the bark.", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0101.jp2"}, "102": {"fulltext": "CHAPTER XI.\\nTHE LEAVES.\\nThe leaves are very important nutritive organs in most\\ngreen plants. They are adapted to catch the sunlight;\\ntherefore their form, structure, and position are largely con-\\ntrolled by this relation to light. (See ^f^f 190, 191.)\\n119. Primary and secondary leaves. Leaves are dis-\\ntinguishable as primary find secondary. The primary leaves\\nare those first developed, usually in the youngest stage, the\\nembryo. In fernworts the primary leaf can be traced back in\\nits development even to the egg. In seed plants they are\\nusually formed before the young plant (embryo) enters its\\nresting state as the seed becomes ripe.\\nThe primary leaves of seed plants are called cotyledons\\n(figs. 85, 86). They are usually transient, and not rarely so\\ndistorted by acting as storage places for reserve food that they\\ndo not serve as foliage leaves at all. In extreme cases of this\\nkind they remain in the seed coats when the embryo resumes\\nits growth, as in pea and oak.\\nSecondary leaves are generally numerous and much more\\nconspicuous. It is these which are usually meant by\\nleaves, unless primary leaves are specially named.\\n120. Development. If the apex of the shoot be ex-\\namined, its progressive differentiation into stem and leaves\\ncan be observed. Upon the sides of the growing point\\nswellings of various size appear, the smallest being nearest\\n96", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0102.jp2"}, "103": {"fulltext": "THE LEAVES.\\n97\\nthe apex (fig. 58, These swellings are the rudiments\\nof the leaves, into which they become transformed by further\\ndevelopment. Similar swellings appear later just above the\\nleaf rudiments, which are at first not distinguishable from\\nthem, except by position (fig. 58, a, b, c). These become\\nthe branches. Both leaf and branch have their origin usually\\nin the outer layers of the shoot, and can only be distinguished\\nFig.\\nFig. 85.\\nFig. 85. A seedling of wheat, with grain still attached, cut through\\nlengthwise, showing the single primary leaf with its back applied\\nto the store of reserve food in the grain (the shaded part). The\\nfirst two secondary leaves are also developing, and the primary\\nroot has extended. Magnified 4 diam.\u00e2\u0080\u0094 After Kerner.\\nFig. 86. Seedlings, showing primary leaves. A, a fir B, the\\ndog-rose C, a morning-glory. Natural size. After Kerner.\\nby the later course of development. The growth of the\\nbranch is commonly indefinite, while that of the leaf is gen-\\nerally limited the branch usually develops leaves and often\\nbuds as lateral outgrowths, while the leaf rarely forms buds\\nnormally; the axis of the branch is generally radial, like the\\nparent axis, while the leaf is generally flattened and dorsiven-\\ntral. In most cases, also, the leaf subtends the branch.\\nBoth leaf and branch mark those points of the stem known\\nas the nodes.", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0103.jp2"}, "104": {"fulltext": "98 OUTLINES OF PLANT LITE.\\n121. Arrangement. Leaves appear in regular succession\\nupon the stem, the youngest being nearest the apex. Their\\ndistribution along the sides of the stem, though extremely\\nvarious, may be reduced to two main types. Either (i) the\\nleaves are formed singly at the nodes, or (2) more than one\\nleaf occurs at each node. When the leaves are single, suc-\\ncessive leaves may stand upon exactly opposite sides of the\\nstem, so that the third leaf, counting from below upwards,\\nstands over the first or the fourth leaf may stand over the\\nfirst or the sixth over the first, and so on. A transverse sec-\\ntion of an opening bud shows the mode of arrangement, and\\na study of such sections makes it evident that each leaf\\nappears in the widest space between the two preceding\\nleaves, i.e., where it encounters the least resistance. That\\nthis is the determining factor is shown by the fact that the\\norder of arrangement may be artificially altered by pressure\\nor distortion of the bud. When two or more leaves occur\\nat each node, the members of successive circles ordinarily\\nalternate with each other. This alternation is due to the\\nsame cause.\\n122. Form. Leaves show a great variety of form and\\nstructure. Even upon the same plant leaves of various forms\\noccur. The primary leaves are usually different from the\\nsecondary leaves, both in form and size. The most abun-\\ndant form of secondary leaves is foliage leaves. These may\\nbe very simple, as the needles of the pines, or differen-\\ntiated more completely, as in the deciduous trees. The\\nmature form of the complex foliage leaf is frequently not\\nattained until several nodes above the point at which the\\nprimary leaves arise; and, if only one or two leaves are pro-\\nduced each season, as in many ferns, the mature form may\\nnot appear for several years.\\n123. Foliage leaves. A well-developed foliage leaf has\\nthree parts, the base, the stalk, the blade (fig. 87). The", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0104.jp2"}, "105": {"fulltext": "THE LEAVES.\\n99\\nleaf base is always present, but either the leaf stalk or the\\nleaf blade or both may be absent. The leaf blade is ordi-\\nnarily winged indeed it is for this reason that it received the\\nname blade. Either the stalk or\\nthe base or both may also be winged.\\n124. i. The leaf base. The leaf\\nbase is generally enlarged so as to\\nform a sort of cushion by which it is\\nattached to the stem. When a broad\\nbase is attached over a considerable arc\\nof the circumference of the stem, so\\nthat it encircles it more or less, the\\nFig. 87. Fig. 88.\\nFig. 87. Leaf of Ranunculus Ficaria. b, leaf base; petiole, or leaf stalk;\\nlamina or leaf blade. Natural size. After Prantl.\\nFig. 88.\u00e2\u0080\u0094 A leaf of a grass, with part of stem to which it is attached, s, sheath (leaf\\nbase) attached all around node k of the stem h, h f, blade the ligule, an outgrowth\\nfrom the surface. Natural size.\u00e2\u0080\u0094 After Frank.\\nbase is said to be sheathing (fig. 87). In grasses, for ex-\\nample, the leaf base is attached over the entire circumfer-\\nence of the stem, and enwraps it completely for a considerable\\ndistance above the node (fig. 88).\\n125. Stipules. The leaf base frequently branches. These\\nbranches, commonly two in number, are called stipules\\n(fig. 89). They vary from slender, awl-shaped bodies to", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0105.jp2"}, "106": {"fulltext": "100\\nOUTLINES OF PLANT LLFE.\\nflattened and leaf-like ones. The stipules may remain\\nattached to the base throughout the life of the leaf, or may\\nfall away early. Usually the two are separate, but they may\\nbe united with the leaf base itself, forming wings for it, as\\nin roses (fig. 90), or they may be united with one another so\\nas to form a sort of sheath encircling the stem (fig. 91).\\nWhen the leaf base is winged, the wings extend downward\\nFig. 89. A growing shoot of a thorn (Cratcegns punctata), n, leaves developed as\\nbud scales which protected the parts above when in the bud S, stipules. Natural\\nsize.\u00e2\u0080\u0094 After Reinke.\\nas lobes more or less encircling the stem. In many cases\\nthe leaf is said to be clasping (fig. 92). These lobes may\\neven unite on the other side of the stem, so that the stem\\nseems to penetrate the base of the blade (fig. 93). When\\ntwo leaves occur at the same node, corresponding lobes\\nof the leaf bases may unite, so that the stem seems to pass\\nthrough the center of a leaf which extends equally on each\\nside of it (fig. 94).", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0106.jp2"}, "107": {"fulltext": "THE LEAVES. 101\\n126. 2. The leaf stalk. The leaf stalk is also known as\\nthe petiole. Its form is more or less cylindrical, usually\\nwith a groove or channel upon the upper side. Sometimes\\nFig. 90. A young flowering shoot ot dog-rose, showing arious forms of leaves and\\ntransition from one to the other. n x -n h scale leaves; W 3 foliage leaves; /z 1 3\\nbracts; the flower leaves not clearly shown. The scale leaf, m 1 shows a leaf base,\\nwinged by stipules 6, with only a trace of stalk and blade a. Trace these parts into\\nfoliage leaves, where the blade becomes compound, and subsequent reduction through\\nthe series of bracts. Natural size.\u00e2\u0080\u0094 After Luerssen.\\nthe petiole is flattened in a vertical plane, as in aspen poplars.\\nWhen this flattening is extensive, so that the petiole becomes\\nthin and leaf-like and the blade is wanting, it functions as a\\nfoliage leaf (fig. 95). Not infrequently, the petiole is", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0107.jp2"}, "108": {"fulltext": "102\\nOUTLINES OF PLANT LIFE.\\nJfc\\nwinged, as in the orange. It may be entirely wanting, in\\nwhich case the blade arises directly from\\nthe base, as in most grasses (fig. 88).\\n127. 3. The leaf blade.\u00e2\u0080\u0094 To this part\\nof the leaf the word leaf itself is fre-\\nquently applied. In gen-\\neral, the leaf blade is so\\nbroadly winged as to be\\nthin and flat; but all\\ngradations exist between\\nsuch forms and those that\\nare much folded or crum-\\npled, thick and fleshy, or\\nFig.\\nFig. 92.\\nFig. 91. Stipules of Polygonum forming\\nsheath, a, above the sheathing leaf base s,\\nthe cut-off leaf cc, the stem ca, an axillary ^..^t, K,-\u00c2\u00bb^i-iVol\\nshoot. Natural size. -After Frank. even C} linariCai.\\nFig. 92. Leaf of I klasfii with clasping base.\\nNatural size. After Prantl.\\nIf a thin blade be held\\nFig. 93. Fig. 94.\\nFig. 93. Shoot of Uvular ia, showing perfoliate leaves below. About half natural\\nsize. After Gray.\\n94.\u00e2\u0080\u0094 A shoot of wild honeysuckle, showing upper leaves connate-perfoliate.\\n-After Gray.\\nFig.\\nAbout half natural size.", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0108.jp2"}, "109": {"fulltext": "THE LEAVES. IO3\\nbetween the eve and the light, two parts become evident:\\n(1) a green tissue, more or less opaque; and (2) translu-\\ncent nerves or veins. The larger of these, usually\\ncalled the ribs, frequently form ridges upon the under\\nsurface.\\nFig. 95. -A shoot of Acacia, showing at a a twice-branched (compound) leaf with\\nroundish petiole at b. a similar leaf with flattened blade-like petiole at c, phyllodia,\\ni.e., blade-like petioles without true blades. About half natural size After Frank.\\n128. Branching. The outline of the blade is extremely\\nvarious. It is dependent upon the character and extent of\\nits branching, which may be either slight or extensive.\\nSlight branching gives rise to teeth of various forms (fig. 96).\\nMore profound branching is evident in divided or parted\\nleaves (fig. 97). In some blades the branching is so exten-\\nsive and complete that the green tissue no longer fills the\\nThese words must not be thought to indicate any resemblance in\\nfunction to the same parts in animals, but only similarity of position or\\nappearance.", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0109.jp2"}, "110": {"fulltext": "104\\nOUTLINES OF PLANT LIFE.\\nintervals between the larger ribs, but the blade is made up\\nof a series of independent portions united to a common stalk.\\nEach ultimate branch of the blade is known as a leaflet.\\nBlades in which the green\\ntissue is continuous, even\\nthough deeply divided, are\\nB\\nFu;. 96. Fig. q\\nFig. 96.\u00e2\u0080\u0094 Diagrams of slight leaf branching. A leaf with crenate edge B, leaf with\\ndentate edge C, leaf with serrate edge. After Bessey.\\nFig. 97 \u00e2\u0080\u0094Leaf of A morfhophallus, showing sympodial branching. The successive\\nlateral axes are numbered in order. The extent of branching makes the blade divided.\\nReduced. -After Sachs.\\ncalled simple leaves. (See figs. 87, 89, 92, 96, 97.) Those\\nwhich are branched into distinct leaflets are called compound\\nleaves. (See figs. 90, 95.)\\n129. Venation. The ribs and veins, being composed in\\npart of the vascular strands which enter the leaf, and in part\\nof stiffening mechanical tissues, branch profusely and in such\\na way that no part of the green tissue is far from a vein. In\\nfigures 98 and 99, though none of the finest branches are\\nshown, some idea of the complete distribution of the veins\\nmay be obtained.\\nThe branching of the ribs and veins agrees in the main with the differ-\\nent modes described for the shoot, 89, which see. A formal account of\\nvenation may be found in Gray s Structural Botany, pp. 90-94.\\n130. Special forms. Foliage leaves may be modified to\\nserve special purposes without wholly losing their function", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0110.jp2"}, "111": {"fulltext": "THE LEA FES. IO$\\nas foliage. For example, the petiole may be made sensitive\\nto contact, and adapted to wrap about slender objects, like\\na tendril, as in clematis and nasturtium (fig. ioo). Such\\nplants are called leal-climbers.\\nSome plants develop their leaves into the form of sacs or\\nFig. 98. Fig. 99.\\nFig 98. Parallel venation of leaf of Polygonattim latifolizim. Natural size. After\\nEttingshausen.\\nFig. 99. Pinnately netted venation of leaf of a willow. Natural size. After Ettings-\\nhausen.\\npitchers. These ordinarily represent the blade of the leaf,\\nand are more or less urn- or trumpet-shaped. They may be\\neither without petiole, as in Sarracenia (fig. 101); or\\npetioled, as in Utricularia (figs. 221, 222); or the petiole", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0111.jp2"}, "112": {"fulltext": "o6\\nOUTLINES OF PLANT LIFE.\\nmay be winged to serve for foliage, as in Nepenthes (fig.\\n220). A few plants have their leaves modified so as to serve\\nas traps, which, by their\\nsudden movements, capture\\nsmall animals (figs. 224,\\n225, 226).\\nBut generally the foliage\\nfunction is subordinated to\\nthe other work, and the leaf\\ntakes on peculiar forms, the\\nmore important of which are\\nas follows:\\n131. (1) Tendrils.\u00e2\u0080\u0094 The\\nleaf blade alone, or some of\\nFig. too.\u00e2\u0080\u0094 Portion of a plant of the dwarf its branches, Or the petiole\\ngarden-nasturtium (Tropceolum minus)\\nThe long petiole a, a. a of the leaf i is and blade, may develop as\\na cylindrical body, without\\nwings and sensitive, known\\nas a tendril. In the pea, the stipules become very large,\\nand take the function of the reduced blade (fig. 102). In\\nother plants the base may be broadly winged for the same\\npurpose.\\n132. (2) Thorns. The leaves may develop into slender\\nconical and sharp-pointed thorns or spines, either branched\\nor unbranched (fig. 228). Sometimes the stipules alone\\nbecome thorns, as in locust and acacia (fig. 103). Neither\\ntendrils nor thorns can be distinguished structurally from\\nsimilar forms of the shoot.\\n133. (3) Scales. In buds, on underground stems and on\\nvarious parts of the aerial stem, are found small, scale-like\\nleaves of various shapes (figs. 63, 64, 67, 71, 89, 90, 198).\\nThese scales may represent the sheathing base only; they\\nmay be the base with the stipules (fig. 90) or they may\\nrepresent the leaf base and the blade. The petiole in all\\nThe long petiole a, a. a of the leaf is\\nsensitive to contact and has coiled about\\nthe support and its own stem, st. z, axil-\\nlary branch. Natural size.\u00e2\u0080\u0094 After Sachs", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0112.jp2"}, "113": {"fulltext": "THE LEAVES.\\nIO/\\ncases is wanting. In addition to the adaptation of their\\nform, scales, especially those that protect buds, are firm and\\nresistant to cold and other unfavorable external conditions.\\nNot infrequently they are supplied with hairs or surface\\nglands, whose function is to produce and excrete resins and\\nFig. ioi. Pitcher-plant {Sarracenia ur/ urei Leaf above A cut off to show\\ntrumpet form One-third natural size \u00e2\u0080\u0094After Gray.\\nsimilar materials which make the parts so covered waterproof.\\nThe inner scales of buds (fig. 60) are often covered with an\\nabundant coating of woolly hairs, wmich serve to prevent\\nrapid change of temperature in the interior of the bud.\\n134. (4) Flower leaves and bracts. On certain parts of\\nthe stem, leaves are commonly profoundly modified to carry\\nthe spore cases (c, st, fig. 66). (See p. 196.) Close below\\nthese are others which may be highly colored and adapted", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0113.jp2"}, "114": {"fulltext": "io8\\nOUTLINES OF PLANT LIFE.\\nin form to protect the inner ones, and to facilitate the visits\\nof insects (s, p, fig. 66). A shoot whose leaves are thus\\nclustered and specialized constitutes a flower. The\\nleaves adjacent to the flower leaves are also more or less\\nmodified in form and reduced in size.\\nThey are called bracts (h I,2 -3 fig. 90).\\n135. (5) Storage leaves. Other\\nleaves are utilized for purposes of stor-\\nage. For this purpose the ribs are re-\\nduced in number and size, while the\\nsofter tissues of the leaf are often\\nFig. T02. Fig. 103\\nFig. 102. Portion of shoot of pea, with a pinnately compound leaf whose upper\\nleaflets are modified into tendrils and the stipules greatly developed to serve as foliage\\nAbout half natural size.\u00e2\u0080\u0094 After Frank.\\nFig. ro3. Piece of the stem of locust {Robin ia Pseudacacia), showing stipules in the\\nform of thorns. Natural size. After Kerner.\\nenormously developed, and serve as the receptacles of\\nthe reserve food. The primary leaves of the seed plants\\n(cotyledons) are often much distorted by the deposit in them\\nof reserve food for the embryo. When such leaves possess\\nsheathing bases the structure resulting from the union of a\\nnumber of such leaves upon a short axis is called a bulb.", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0114.jp2"}, "115": {"fulltext": "THE LEAVES.\\n109\\n(See also 93.) The leaves of buds are sometimes thick-\\nened by the deposit of food material, and when such buds\\nloosen from the plant they may produce a new plant, as in\\nthe tiger-lily (see 299). Both base and blade may be used\\nfor storage, as in the century-plant; or the entire leaf may\\nserve the same purpose, as in the cultivated cabbage.\\n136. Structure. Three regions in each part may be distinguished, as\\nin the root and stem (1) the epidermis (2) the cortex both continu-\\nous with that of the stem (3) the steles, continuous with those of the\\nstem when the latter contains several steles, or branches of it when the\\nstem contains a single stele.\\nThe structure of the petiole agrees in all essentials with that of the\\nstem (see ^j 107, ff. The following is a brief summary of the structure\\nof the blade of a foliage leaf.\\nFig. 104* Surface view of epidermis from under side of leaf of bracken fern (Pteris),\\nshowing wavy cells, except over veins, v, where they are elongated, st, stomata.\\nThe dot in each cell represents the nucleus. Highly magnified. After Sedgwick\\nand Wilson.\\n137. Epidermis. In broad leaves, the epidermis of the blade is made\\nup of tabular cells, often with wavy lateral walls (fig. 104), and, except\\nin shade plants, usually without green color. It usually consists of one\\nlayer, but in some plants becomes several-layered, either to serve as ad-", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0115.jp2"}, "116": {"fulltext": "no\\nOUTLINES OF PLANT LIFE.\\nditional protection against evaporation or for use as a water-storing\\ntissue. (See 34 2 Numerous narrow slits, each bounded by a pair\\nof specialized cells called guard cells, are formed in the epidermis. The\\nwhole apparatus is called a stoma (figs. 104, 105). The guard cells are\\ncrescent-shaped, and are sensitive to various external conditions, espe-\\ncially light, so as to control the size of the slit-like passage between\\nthem by becoming straighter or more curved (fig. 105). This passage\\nFig. 105. A, perspective view of a stoma from the under epidermis of the beet leaf,\\nshowing the sloping sides of the slit, the crescentic guard cells with chloroplasts.\\nsections through stomata of beet at right angles to their length. The upper figure\\nshows the stoma open the lower closed. The black line represents the primary wall,\\nto which additional material, especially in the guard cells, has been added. These\\nthickenings serve by their elasticity to close the stoma. Opening is due to turgor of\\nthe guard cells. The chloroplasts and granular protoplasm are shown. Highly mag-\\nnified.\u00e2\u0080\u0094 After Frank.\\nThe stomata are\\nhere enclosed,\\n30,000, some-\\nto 70,000 in\\nsq. cm.\\nis formed by the partial splitting apart of the guard cells and com-\\nmunicates with extensive spaces between the green cells in the in-\\nterior.\\nnumerous. In different plants, in the space\\nthe numbers usually vary from 4000 to\\ntimes, however, reaching as many as 60,000\\nthe olive and rape. They are not equally\\ndistributed on the two sides of the leaf, being usually more numerous on\\nthe under side, where there are more internal spaces. They may be\\nwanting on the upper side, as in lilac, begonias, and oleander. There\\nare no stomata on submerged leaves nor on the under side of floating\\nleaves. In some plants they are found in clusters, in others uniformly\\ndistributed.\\n138. Cortex. The cortex of leaves is called the mesophyll. It con-\\nsists of thin-walled, active cells, for the most part richly supplied with\\nchloroplasts. In very thick leaves the internal cells are colorless. In\\nsome leaves the cells of the mesophyll are nearly uniform, but in most", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0116.jp2"}, "117": {"fulltext": "THE LEA VES.\\nIll\\nthose near the upper surface are more elongated and close set, form-\\ning one or two rows, with their ends outward, while cells near the\\nlower surface are irregular in form, with large intercellular spaces\\n(fig. 106).\\nThe cortex (gs, fig. 106) often develops along the larger steles into\\none or two strands or a sheath of mechanical tissues. These tissues, to-\\nFig. 106. Diagrammatic vertical section of a leaf, e, e, epidermis, with cuticle c, c,\\nand stomata, sA, s/ Between upper and lower epidermis lies the mesophyll, with\\ncells abundantly supplied with chloroplasts. The upper row of elongated cells is the\\npalisade parenchyma; the rest form the spongy parenchyma, both with many inter-\\ncellular spaces a, i, f, communicating with outside air through stomata. In the meso-\\nphyll lies a small vein, here cut across, composed of a ventral wood bundle a\\ndorsal bast bundle s, surrounded by the endodermis gs, and the pericycle (between\\ng and gs). After Sachs.\\ngether with a stele, constitute the rib or vein, often so massive as to pro-\\nject beyond the other parts in thin leaves.\\n139. Steles. The steles are numerous and ramify through the blade.\\nTheir structure is essentially as described for the stem 107). Each\\nof the smaller consists of little more than a single pair of vascular strands.\\nThe wood strands alone form the last branches (fig. 107), the bast disap-\\npearing earlier. The larger ribs may be accompanied by one or two\\nstrands or a complete sheath of mechanical tissues, and the vascular", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0117.jp2"}, "118": {"fulltext": "112\\nOUTLINES OF PLANT LITE.\\nstrands may be increased by the development of secondary wood and\\nbast. (See ^114-)\\nThe growth of the leaves is ordinarily limited, rarely extending over\\na single season. In a few ferns and coniferous plants the leaves live for\\ntwo to eight years, and some continue to grow for a longer time than\\none season.\\nFig. 107. Fig. 108.\\nFig. 107. A few meshes of the finest veins of a leaf of A nthyllis. m, main vein b, b,\\nbranches a, a, a, a closed mesh c, ends of the finest veins within the mesh. The\\ndrawing shows only the wood bundles the bast bundles accompanying them and\\nthe mesophyll cells filling the meshes are not shown. Moderately magnified.\u00e2\u0080\u0094 After\\nSachs.\\nFig. 108. Ending of a vein in the mesophyll of a leaf, v, v, v, the spirally thickened\\ncells of the wood; c, c, mesophyll cells with chloroplasts a, a, cells specialized to\\ntransfer water from wood to mesophyll. Magnified 230 diaro. After Frank.\\n140, Wintering. In those plants which live from year\\nto year, producing new leaves each spring, the unfolding ot\\nthese from the winter buds is due chiefly to the enlargement\\nof the rudimentary leaves already formed. New leaves are\\nordinarily produced before the close of the growing season\\npreceding that in which they are expanded, and are protected\\nin the winter buds. The partly developed leaves in the bud", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0118.jp2"}, "119": {"fulltext": "THE LEAVES. 1 1 3\\nmay be flat, but broad leaves are commonly folded or rolled\\nin various ways.\\n141. Production of the other members. Leaves give\\nrise under certain conditions to roots or to shoots. The\\nnumber of plants, however, in which this occurs is compara-\\ntively limited. Roots arise from leaves in precisely the same\\nway as lateral roots arise from stems (^f 84), that is, they are\\ninternal in their origin, and begin to develop always near the\\nsurface of a stele.\\nWhen a leaf produces a shoot, it is from the epidermis or\\nfrom the green tissue underlying it, never from a stele.\\nShoots thus arise from the part of the leaf correspond-\\ning to that from which branches arise upon the parent\\nshoot.\\n142. Leaf fall. Leaves, like roots and stems, undergo\\ncertain secondary changes, but these are neither so common\\nnor so extensive as in the other two members. One of the\\nsecondary changes of most importance is the preparation for\\nthe fall of the leaf. This is made by the formation of a\\ntransverse plate of cells, some of which may become trans-\\nformed into cork, making a line of weakness; or, without\\nsuch alteration, the cells may round themselves off by\\nloosening along a definite line, so that the leaf is held only\\nby the steles. The access of water to this crevice, and its\\nfreezing, serve to rupture the remaining tissues, and thus\\nallow the leaf to fall by its own weight, or to be torn off by\\nthe wind.\\nThe scar left by the fall of the leaf is protected either by\\nthe cork already produced, or by mere drying of the exposed\\ntissues. The leaflets of compound leaves fall in like manner.\\nSometimes provision for the leaf fall is begun as early as\\nJune, as in the Kentucky coffee-tree. In other plants pro-\\nvision for leaf fall is begun late in the season, and in some,\\nsuch as the oaks, it is very imperfect, so that the leaves are", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0119.jp2"}, "120": {"fulltext": "114 OUTLINES OF PLANT LIFE.\\nfinally wrenched off by winter storms, or pushed off in the\\nspring by the developing buds beneath them.\\nEXERCISE XIX.\\nLeaves. Examine the forms, branching, and venation of such leaves\\nas can be secured. Unfolding buds show modes in which leaves are\\nfolded or rolled. Special directions for study seem unnecessary. A\\ndemonstration of the structure of a lily or lilac leaf 136-139) is\\ndesirable. (For flower leaves see p. 210.)\\n143. Summary. The form, structure, and position of\\nfoliage leaves are chiefly dependent upon the amount and\\ndirection of light. The first leaf or leaves of the embryo are\\nusually transient; even secondary leaves rarely live more\\nthan a single season. They arise in regular succession on\\nthe stem and at such points as are least crowded. The parts\\nof a leaf are blade, base, and stalk; any one or two may be\\nwanting. The base is often sheathing or branched to form\\nstipules. The stalk may be winged to act as a blade. The\\nblade is in one piece or more or less branched into lobes or\\ninto leaflets. The veins, containing vascular strands, supply\\nall parts with water, and when strong prevent tearing. The\\nleaf rudiment, instead of developing into a foliage leaf, may\\nform a pitcher, a tendril, a thorn, a scale, a flower leaf, a\\nstorage place, etc. The internal spaces of the leaf connect\\nwith the air through stomata, which are guarded by a pair of\\nvalve-like cells. These by changing form can regulate the\\nevaporation of water from the leaf, and also permit ready\\nentrance of air. Leaves often live over winter in a rudimen-\\ntary condition in the bud. They fall usually because of the\\nformation of a separation layer of cells across the leaf base.", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0120.jp2"}, "121": {"fulltext": "PART II. PHYSIOLOGY.\\nCHAPTER XII.\\nINTRODUCTION.\\n144. Division of labor. The study of the external form\\nand internal structure of plants may be carried on as well\\nupon dead as upon living material. Even the observation\\nof the course of development requires only the examination\\nof the plant as it exists at a particular moment. But the\\nplant may also be studied as a working organism. For this\\npurpose living material is indispensable. The work that\\nplants do, by which they are distinguished from non-living\\nbodies, is extremely varied, and the more complex the plant\\nthe more varied it is. In the preceding part the aim has\\nbeen to show that there exists great variety of form, and that\\nfrom the smaller to the larger plants there is gradually in-\\ncreasing complexity by differentiation into tissues and\\nmembers.\\nNutrition, respiration, growth, movement, and reproduc-\\ntion are all executed by the single cell of the simplest plant.\\nBut with specialization in structure there occurs division of\\nlabor. Each kind of physiological work is known as a\\nfunction, and each part of the organism which does a par-\\nticular work is called an organ.\\n145. Physiology and ecology. Physiology proper treats\\nof the plant at work, discussing the different functions and\\nthe way in which these are affected by external forces, such\\nas light, heat, etc. In its broadest sense it also treats of the\\n115", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0121.jp2"}, "122": {"fulltext": "Il6 OUTLINES OE PLANT LIFE.\\nrelation of the plant as a whole to external forces and to\\nother living beings, both plants and animals. But it is con-\\nvenient to separate the latter from physiology proper as\\necology* (See Part IV.)\\nThe study of physiology proper requires methods of controlling these\\nexternal forces, carefully planned and repeated experiments, and cau-\\ntious inferences.\\nThe study of ecology requires observation, in the field, of the physical\\nsurroundings of plants, of their relation to their neighbors, and of their\\nadaptations to prevent injury by unfavorable physical conditions and the\\nattacks of other beings, and to take advantage of the favorable forces and\\nbeneficent agents.\\n146. Chemical and physical forces. The functions of a\\nplant may be divided for the sake of convenience into nutri-\\ntion, respiration, growth, movement, and reproduction.\\nThese are largely special modes of chemical and physical\\naction. Nutrition and respiration, for example, consist\\nchiefly of a series of chemical changes; while movement is\\nmainly a result of physical alterations in certain organs.\\nBut the action of chemical and physical forces does not\\nsuffice at present to explain all the activities of the living\\nplant. Moreover, the peculiar manifestation of these forces\\nwhich we call life occurs only in connection with the sub-\\nstance which we call protoplasm.\\n147. The powers of protoplasm. Although only a por-\\ntion of any plant is composed of living matter, it is to that\\nliving matter only that we are to look for the seat of its\\npowers.\\nThe fundamental powers of protoplasm are four; it is\\nmetabolic, irritable, contractile, and reproductive.\\n148. Metabolism. Protoplasm is metabolic, that is, it is\\ncapable of initiating chemical changes in itself and in sub-\\nSpelled in lexicons, cecology, but best usage drops the o; sometimes\\nimproperly called biology or plant biology.", "height": "3516", "width": "2261", "jp2-path": "outlinesofplantl00barn_0122.jp2"}, "123": {"fulltext": "PHYSIOLOGY. 117\\nstances which come directly under its influence. These\\nchanges are of two kinds. They may be constructive, i.e.,\\nthey may build up complex substances out of simpler ones,\\nand so fit them for use in repairing the waste caused by the\\nactivity of the protoplasm; or they maybe destructive, i.e.,\\nthey may break down complex substances into simpler, so\\nsetting free the energy necessary for the work of the proto-\\nplasm. The substances broken down may be repaired in\\nwhole or in part, i.e., may take part in constructive met-\\nabolism. Those in which no repair occurs often undergo\\nfurther destructive changes by which they become converted\\ninto materials useless to the plant, and to be gotten rid of.\\nMetabolism, therefore, includes all the chemical changes\\nby which food is either manufactured or utilized, and by\\nwhich waste materials are produced and eliminated.\\n149. Irritability. Protoplasm is irritable, that is, it\\nexists in such a state that it is sensitive to external influences,\\nwhich thereby affect the various functions of the whole\\nplant. By reason of its irritability, it may even transmit the\\neffects of an external stimulus from one part to a distant\\npart. Moreover, it is capable of initiating similar changes\\nwithout the action of any observable external influences, and\\nis, therefore, not only irritable but automatic.\\n150. Contractility. Protoplasm is contractile, that is, it\\nhas the power of altering its form, of shortening in one direc-\\ntion and elongating in another, by virtue of inherent forces\\nwhose action is not understood.\\n151. Reproduction. Protoplasm is reproductive, that is,\\nit is capable of so directing the chemical and physical forces\\ninherent in it that a new organism similar to that of which it\\nforms part may be produced.\\n152. Adaptation. The interrelation of these powers,\\ntheir harmonious co-working and their variation to suit the\\nvarying conditions of the surrounding media (air, water,", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0123.jp2"}, "124": {"fulltext": "lib OUTLINES OF PLANT LIFE.\\nsoil, etc.), result in the proper performance of all the func-\\ntions of the plant. By means of these powers it is brought\\ninto relation to the world about it, being adapted to other\\norganisms in whose company it lives, and enabled to with-\\nstand the adverse conditions by which it is frequently\\nthreatened. Every organism, indeed, must adjust itself first\\nto the external physical conditions, and, second, to other\\norganisms. (See Part IV.)\\n153. Physical conditions set limits upon the discharge of\\nits functions. Varying amounts of light, of heat, of moist-\\nure, determine more or less rigidly how rapidly, or to what\\nextent, each function may be discharged. Every function of\\nthe plant is adapted, therefore, to an upper limit, the maxi-\\nmum, and to a lower limit, the minimum, above or below\\nwhich the performance of the function in question is im-\\npossible. Between these limits there lies some point at\\nwhich it proceeds most rapidly and effectively. This point\\nis known as the optimum.\\n154. Summary. Increasing size and complexity permits\\nan advantageous division of labor among different organs.\\nPhysiology treats of the work of the plant as a whole;\\necology of its adaptations to external conditions and to other\\norganisms. All plant work depends on the living proto-\\nplasm. Its power of initiating and carrying on chemical\\nchanges in itself and other substances provides for nutrition\\nits power of receiving impressions from the world about\\nenables it to regulate all its work and adapt itself to its sur-\\nroundings; its power of contractility enables it to move; and\\nits power of making and separating special parts of its own\\nsubstance secures a succession of like plants. All work is\\nlimited by the physical conditions which surround the plant,\\nand may bring any or all of them to a standstill, because the\\nplant can only adjust itself to them within narrow limits.", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0124.jp2"}, "125": {"fulltext": "CHAPTER XIII.\\nTHE MAINTENANCE OF BODILY FORM.\\nEvery plant is capable of attaining and maintaining a\\nspecific form, which is not permanently altered by the direct\\naction of external forces, and is dependent upon the nature\\nof the plant itself.\\n155. Naked cells. If the plant consists of a single mass\\nof naked protoplasm, it may assume a spherical or ovoid\\nshape (fig. 109). In attaining this form the physical forces\\nFig. iog. Zoospores (naked pro.oplasm) of various kinds, swimming in water by means\\nof one or more cilia. A, Botrydium B, Draparnaldia C, Coleochcete D,\\nCEdogoninm. Highly magnified.\u00e2\u0080\u0094 After Kerner.\\nplay a part, but the form is determined chiefly by unknown\\ninternal forces peculiar to living protoplasm. This is par-\\nticularly well shown when such organisms extend delicate\\nprotoplasmic threads, the cilia (fig. 109), and maintain these\\n119", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0125.jp2"}, "126": {"fulltext": "120\\nOUTLINES OF PLANT LIFE.\\nin active motion, or when they extend a large portion of\\nthe body for creeping (fig. no). The extension of such\\norgans, whether slender or thick, is directly opposed by\\nstrong physical forces acting at the surface which tend to\\ncontract the body into a sphere, as they do a drop of liquid.\\nFig. no.\u00e2\u0080\u0094 Plasmodia, creeping bits of naked protoplasm, showing varied shapes as\\nparts are protruded or withdrawn. Highly magnified. After Kerner.\\n156. Turgor. If the organism be one surrounded by a\\ncell-wall, or if it be made up of a number of cells united,\\nthe cell-wall itself plays a considerable part in maintaining\\nthe form. This is due to the condition of the cell known as\\nturgor. When fully mature the cell -wall of each active cell\\nis lined by a more or less thick layer of living protoplasm.\\nIn the interior of the protoplasm there exist one or more\\nwater chambers, the vacuoles 4, and fig. 117). If such a\\ncell as this be measured in its normal condition, and then\\nsurrounded for a few moments by a 10 per cent, solution of\\ncommon salt, re-examination will show that the vacuoles\\nhave been diminished and the protoplasm shrunken away\\nfrom the wall; remeasurement will show that the cell has\\ndiminished both in length and diameter. In its normal con-\\ndition, therefore, the wall was stretched by the pressure of\\nthe contents within. If a cell which has been thus shrunken\\nby immersion in a solution of salt be again placed in water, it\\nmay regain, in the course of a few hours, its original condi-\\ntion, that is, it may again become turgid. This would be\\nbrought about by the entrance of water into the vacuoles to", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0126.jp2"}, "127": {"fulltext": "THE MAINTENANCE OE BODILY FORM. 121\\nreplace that withdrawn when the cell was placed in the solu-\\ntion of salt.\\nIf a thin piece of rubber tubing be connected with a pump\\nand filled with water until it is stretched, it increases its\\ndiameter and length slightly, and gains, at the same time, a\\ncondition of rigidity greater than in its unstretched condition.\\nIn a similar way turgid cells are more rigid than those which\\nare flaccid. The union of turgid cells produces a member\\nmore rigid than one in which the cells are not turgid. An\\nillustration of this is to be seen in the condition of a wilted,\\nas compared with a fresh, leaf. The turgor of thin-walled\\ncells may play an important part in maintaining the form\\nand position of the parts of a plant.\\nEXERCISE XX.\\nDemonstration. To show the existence of turgor in the individual cell.\\nMount a bit of Spirogyra under microscope observe position of\\nchlorophyll bands. Irrigate with 5 per cent, solution of salt and note\\neffect.\\n(If Spirogyra is not at hand use hairs on stamens of Tradescantia or\\nthe epidermis, filled with purple cell sap, from the under side of the\\nleaves of the variegated Tradescantia wandering Jew or the hairs\\nof geranium leaves.\\nTo show effect of turgor of cells on rigidity of young parts containing no\\nmechanical tissues.\\nRemove carefully a young plant with vigorous primary root grown in\\nsawdust or moss. Lay in water for a few minutes. Note rigidity.\\nTransfer to 5 per cent, salt- solution for a few minutes. Has rigidity in-\\ncreased or diminished Remove to water again for 15 min. What is\\nthe result\\n157. Tissue tensions. But turgor can affect only those\\ncells whose walls are thin and extensible. Those whose\\nwalls have become thick and rigid are not stretched by this\\nforce. In the larger plants, however, where both thick-\\nwalled and thin-walled tissues exist, it is possible that a mass", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0127.jp2"}, "128": {"fulltext": "122\\nOUTLINES OF PLANT LIFE.\\nof thin-walled cells may, by the united tension of its com-\\nponent cells, stretch those tissues which are not themselves\\nturgid. Such strains in the younger regions, particularly,\\nplay an important role in maintaining the form of these\\nparts. But the tensions in the older parts are generally due\\nto the unequal growth of different tissues. (See 218.)\\n158. Mechanical rigidity. The rigidity of the cell-wall\\nitself must be relied upon by all the larger plants. Certain\\ntissues are specialized by having their cell-walls greatly\\nthickened, and such tissue regions constitute a sort of frame-\\nwork or skeleton, which is filled out by the more delicate\\nparts. These mechanical tissues are so distributed within\\nthe body as to afford frequently the maximum resistance to\\nbending and breaking strains.\\nIn the accompanying diagrams the position of the mechanical tissues is\\nindicated in transverse sections of a number of different stems (fig. 111).\\nIt will be seen that they illustrate well-known mechanical principles in\\nC D E\\nFig. hi. Diagrams showing the arrangement of mechanical tissues and vascular strands\\nin the cross-section of various stems. The mechanical tissue is gray the vascular\\nstrands black, with white dots. A, linden (young); B, a mint; C, a sedge; D, a\\nbamboo E, a grass. After Kerner.\\ntheir distribution. The hollow column (E) and the I-beam (A, B, C),\\ntwo of the most rigid mechanical constructions, are frequently imitated\\nin plants.", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0128.jp2"}, "129": {"fulltext": "THE MAINTENANCE OF BODILY FORM. 1 23\\nIn stems of trees rigidity is secured not by the distribution\\nof the mechanical tissues, but by their massiveness. In\\nthem the chief mechanical tissues belong to the wood, which\\nforms a solid column occupying the center of the body.\\nAquatic plants, which are supported by the medium in which\\nthey live, are usually without mechanical tissues.\\n159. Summary. Bodily form is maintained by naked\\nprotoplasm chiefly by unknown forces inherent in the living\\nsubstance. In larger plants it is maintained partly by turgor,\\nwhich develops opposing strains in masses of cells, and partly\\nby the mechanical stiffness of the cell-walls formed by the\\nprotoplasm. These rigid parts are either massed or definitely\\nplaced in the plant body, so as to carry its weight and meet\\nthe strains due to winds, water-currents, etc.", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0129.jp2"}, "130": {"fulltext": "CHAPTER XIV.\\nNUTRITION.\\n160. Repair and growth. Since the body of every plant\\nis constantly wasting away by reason of its own activity, it\\nis necessary that it should be as constantly repaired. It\\nmust also, for a considerable time or throughout its whole\\nlife, be furnished with material which can be used in the\\nmaking of new parts. Without an adequate supply of food,\\nIherefore, neither repair nor growth is possible. To under-\\nstand what materials are necessary for repairing waste and\\nforming new parts of the living plant, the constituents of a\\nplant may be determined by chemical analysis.\\n161. Chemical composition. The greater portion of the\\nweight of every plant is found to be water. Of the firmer\\nparts it forms as much as 50 per cent while of the softer\\nparts it may form 75 or even 90 per cent. The most watery\\nportions of some plant bodies, such as the juicy portions of\\nfruits and the whole body of the algae, may contain only 2 to\\n5 percent, of solid matter.\\nIf the solid matter left after driving off the water at a temperature of\\nno\u00c2\u00b0 C. is burned, there remains a white material which crumbles under\\npressure, the ash. The dry matter consists chiefly of three elements,\\ncarbon, hydrogen, and nitrogen. The most abundant element in\\naddition to these is nitrogen. When the dry substance is burned\\nthese four elements are driven off in gaseous form. An analysis of the\\nash reveals the presence of sulfur and phosphorus in considerable amounts,\\nand also smaller quantities of the following elements: calcium, magne-\\n124", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0130.jp2"}, "131": {"fulltext": "NUTRITION. 125\\nshim, potassium, iron, sodium, chlorine, and silicon. Of these seven, the\\nfirst lour are found in the ash of all plants, and the remaining three are\\n\\\\vr\\\\ common. In addition to the elements enumerated, about 25 others\\nare known to occur in the ash of plants, but only in minute quantities.\\nA. The water in the plant.\\n162. Necessity. Since water forms such a large percent-\\nage of the weight of fresh plants, it is manifest that it must\\nbe supplied in relatively large quantities, if the plant is to\\ncontinue in an active condition. A portion of this water\\nmay be used up in the chemical changes occurring in the\\nbody, but it is not possible to discriminate between this and\\nthe water which is necessary to furnish the proper physical\\nconditions of life. Water is the great solvent in which\\nmaterials of various kinds enter the plant body, and by which\\na still greater variety within it are transported from place to\\nplace. Before discussing the food of plants, therefore, the\\nrelation of water to the plant may be examined.\\n163. Air, water, and land plants. Some plants are not\\nin contact with water except at irregular intervals. These are\\ncalled air plants, and include some algse, liverworts, mosses,\\nfernworts, and seed plants. All these, however, are able to\\nlive only in an atmosphere containing large quantities of\\nwater vapor, or in those regions where they are frequently\\nsprayed with water. Water plants float upon the water, or\\nare submerged in it. As distinguished from both air and\\nwater plants, are those which have the root system (and some-\\ntimes a portion of the stem buried in the soil) continually or\\nintermittently in contact with liquid water, while the shoot\\nsystem is occasionally sprayed by rain. Such may be called\\nland plants.\\n164. Solutions in water. In no case, however, is the\\nwater in which plants are immersed, or with which they are\\nsprayed, pure water. It always holds in solution substances", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0131.jp2"}, "132": {"fulltext": "126 OUTLINES OF PLANT LIFE.\\nderived from the atmosphere or from the soil with which it\\nhas come in contact. These substances, whether organic or\\ninorganic, enter the plant, together with the water, through\\nthose organs which are adapted to absorption.\\n165. Absorption of water. In air plants of the simpler\\nsorts, any parts exposed to the moist air or rain can absorb\\nwater. In liverworts and mosses the thallus or the leaves are\\nactive absorbents. In the higher plants, such as the aerial\\norchids, the external cortex of the roots is especially adapted\\nto absorb liquid water, or to condense the water vapor of the\\natmosphere.* In water plants the surfaces which are normally\\nin contact with the water are absorbing surfaces. Such\\nplants may be either wholly without a root system, or it may\\nbe only sufficiently developed to anchor them in the mud.\\nIn land plants the root system is especially adapted to the\\nabsorption of water. Only minute quantities of water are\\nabsorbed by the leaves and other aerial parts. The root sys-\\ntem of the land plants is developed in contact with the soil.\\nEXERCISE XXI\\nTo show that water is not absorbed by leaves in quantity adequate to\\nsupply evaporation.\\nCut off a vigorous shoot of a plant with abundant foliage; close end of\\nstem with grafting -wax; expose to sunlight until well wilted; then im-\\nmerse it in water. Does the plant recover its turgidity slowly or rapidly\\n166. Soil. The soil consists primarily of finely divided\\nparticles of rock, whose nature and size determine the quali-\\nties by which soils are ordinarily distinguished into gravelly,\\nsandy, loamy, clayey, etc. Mixed with these rock particles\\nis more or less material derived from the offal of plants or\\nanimals. When decaying plant offal predominates, the soil\\nis known as vegetable mold or humus, which naturally forms\\nIf such condensation really occurs (as is generally alleged), it does\\nnot suffice to keep the plants supplied with the required amount of water.", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0132.jp2"}, "133": {"fulltext": "NUTRITION.\\n127\\nthe upper layer of the soil of forests. To garden or field soils,\\nnot naturally rich in organic matter, this is frequently sup-\\nplied artificially by adding manures and artificial fertilizers.\\n167. Soil water. No matter how fine the soil may be,\\nthe rock particles are not in close contact, but, on ac-\\ncount of their angular outline, leave spaces of greater or\\nless size to be occupied by other materials. If a soil be\\nexamined immediately after a heavy rain-fall, these spaces\\nFig. 112.\u00e2\u0080\u0094 Diagram of a portion of soil penetrated by root hairs, h, h arising from\\nroot, e. At z, s, s the hair has grown into contact with some of the soil particles, T,\\nwhich are surrounded by water films 1 shaded by concentric lines), /3, a, t. The white\\nspaces are air-bubbles, 6, 8 y, y When water enters the hair at a, the thichness of\\nthe film a, /3, t will be diminished, and some water will flow towards this point, re-\\nducing all the other water films in the vicinity. More air enters from above When\\nrain falls, the reverse process occurs the films thicken, and the air may be entirely\\ndriven out, to return as the surplus water drains away.\u00e2\u0080\u0094 After Sachs.\\nwill be found completely occupied by rain-water. If the soil\\nbe so situated as to be naturally drained, considerable quanti-\\nties of this water will disappear gradually, and the larger spaces\\nbetween the soil particles will be occupied partly by films of\\nwater adherent to the soil grains, and partly by bubbles of\\nair (fig. 112).\\n168. Salts dissolved. The water which thus filters through\\nthe soil dissolves and retains certain of its constituents. As\\nthe rain passes through the atmosphere it also dissolves cer-", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0133.jp2"}, "134": {"fulltext": "128 OUTLINES OF PLANT LIFE.\\ntain substances found therein, notably minute quantities\\nof compounds containing nitrogen, which are useful to the\\nplants for food making.\\n169. Root absorption. The structure of the root system\\nhas been explained 72-76). The root hairs come into\\nclose contact with the soil particles, pushing them aside\\nsomewhat, and being in turn more or less deformed by their\\nresistance {z, s, fig. 112). So close does the contact of the\\nroot hairs and soil grains become that many particles of the\\nsoil are embedded in the walls of the root hairs (fig. 51).\\nThe root hairs are not only in contact with the soil particles,\\nbut also with the films of water, which occupy the spaces be-\\ntween them (a, fig. 112). They are thus in a position for\\nabsorbing water from the adjacent films.\\nEXERCISE XXII.\\nTo shoiv the location of root hairs and especially their adhesion to soil\\nparticles.\\nGerminate wheat in sand and when seedlings have several strong roots\\ndig up carefully; shake sharply in water; note where soil clings most\\ntenaciously. Brush away most of this with camelhair brush and examine\\na bit of this part of root under a low power of microscope. Observe dis-\\ntortion of root hairs, and particles of sand partly embedded in them.\\n170. Limit of absorption. Not only is the water imme-\\ndiately in contact with the root a source of supply, but even\\nthat in the deep and more distant parts of the soil. For\\nwhen, by the entrance of some water into the root hair, the\\nthickness of that layer has been decreased, the disturbance of\\nequilibrium causes a flow from neighboring layers and this\\ngoes on until the films of water upon the soil grains become\\nso thin that the water particles are held too tenaciously to be\\npulled away by the root. There remains in such exhausted\\nsoil, which seems dry as dust to the touch, 2 to 12 per cent, of\\nwater unavailable for the plant.", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0134.jp2"}, "135": {"fulltext": "NUTRITION. 129\\n171. Solvent action. The root hairs also exert a slightly\\nsolvent action upon the soil particles themselves by reason of\\nthe carbonic acid and the acid salts which they excrete. By\\nthis means various minerals, which could not be dissolved by\\nthe water alone, may be brought into solution.\\nEXERCISE XXIII.\\nTo show excretion of acid salts by roots.\\nFill a wide-mouthed bottle holding 250 cc. with tap water; add 2-3\\ndrops of ammonia and several drops of phenolphthalein. If the water\\ndoes not now remain pink add a drop or two more of ammonia. Select\\na vigorous seedling bean grown in sawdust; rinse roots well to remove\\nimpurities.\\nCut in two a cork which fits the bottle; in the halves cut two cor-\\nresponding notches of such size that with a little cotton for packing the\\nplant will be firmly held. Place the plant with enough cotton to secure\\nit in the cut cork and set in bottle with roots immersed.\\nAs the plant grows from day to day watch for the disappearance of\\ncolor in the solution, which will indicate when the alkaline fluid has be-\\ncome acid. Arrange a control experiment in exactly the same way, but\\nwithout plant. Surround each bottle with opaque shade of heavy paper,\\nto avoid effect of light on the roots and fluid.\\nTo show the corrosion of carbonate of lime by the carbonic acid\\nexcreted by the roots.\\nCover a polished marble slab to a depth of 5 cm. with clean sand, in\\nwhich plant corn or beans. After the plants are 10-15 cm. high, remove\\nsand carefully and rinse off the marble. Examine the surface by reflected\\nlight. A. little graphite rubbed into lines etched by roots will make them\\nmore readily visible.\\n172. Movement of water within the plant. Once the\\nwater has gained entrance to the plant, it must move to those\\nparts where it is to be used i.e., to all the organs of the\\nplant, but especially to the leaves, since from these there is\\nAn indicator for acids, colorless when a fluid in which it is dissolved\\nis acid, rose pink or darker when alkaline. For use the crystallized\\nphenolphthalein is dissolved in alcohol.", "height": "3565", "width": "2153", "jp2-path": "outlinesofplantl00barn_0135.jp2"}, "136": {"fulltext": "130\\nOUTLINES OF PLANT LIFE.\\nthe largest loss of water by evaporation 177). From the\\nroot hairs the water passes inward through the cortex, and\\nreaches the stele. The forces which determine this move-\\nment and its direction are not fully understood. They are\\ncomprehended under the general phrase root pressure.\\n173. Root pressure. The action of root pressure may be\\ndemonstrated by severing a suitable stem close to the ground\\nand observing that water flows out,\\nafter a short time, from the cut end-\\nCareful examination of the cut surface\\nshows that the water is forced out chiefly\\nfrom the woody parts of the stele, and\\nthis continues for a considerable time.\\nThe force with which water is extruded\\nmay be measured by attaching to the\\nstump, by means of a rubber tube, a\\npressure gage (fig. 113). In this way\\nit may be ascertained that in woody\\nplants, such as the birch, the pressure\\nsometimes becomes great enough to\\nsustain a column of mercury about two\\nmeters high (2.5 atmospheres).\\nEXERCISE XXIV.\\nFig. 113. Apparatus for Demonstration. To sliow root pressure as a\\nmeasuring root pressure. r\\nFor explanation see Ex- factor in the movement of water in plants.\\nercise XXIV. p.\\nAfter Sachs.\\nCut off the stem of an actively growing plant\\n(plants of castor bean and tomato 25-30 cm.\\nhigh are especially recommended) a short distance above the soil and\\nfasten tightly to the stump, by means of rubber tubing, a piece of glass\\ntubing a meter long, and about the diameter of the stump. Wrap joint\\nwith tire or electric tape to prevent stretching of rubber and leakage.\\nAdd enough water to rise 10 cm. above the rubber connection. Keep\\nroots well watered and mark the height of the water in tube from time\\nto time until it reaches the top or begins to fall. Does the water rise\\nfrom the first", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0136.jp2"}, "137": {"fulltext": "NUTRITION. 131\\nA more satisfactory record may be reached by attaching to the stump\\na T-tube as shown in tig. 113. To the horizontal arm attach a mercury\\npressure gage. (A pressure gage may be readily constructed by bending\\na glass tube, about 5 mm. diameter (3 mm. bore) and 80 cm. long, upon\\nitself 30 cm. from one end, so that it forms a |J with unequal legs 3-4 cm.\\napart. Bend 5 cm. of the end of the short leg at right angles, in the\\nplane of the (J- Tie the legs to a piece of cork between the legs near top,\\nso that the tube will not be easily broken by the leverage of the legs on\\nthe bottom bend. Fill the space between stump and mercury with water.\\nIn the third arm insert a short tube drawn out to a slender point to per-\\nmit the escape of air and extra water. Seal this with a flame after filling.\\nThere must be at least 15 cm. of mercury in U -portion, of manometer.\\nAt beginning mark, with a bit of gummed paper, height of mereury in\\neach leg; measure difference at intervals thereafter until mercury begins\\nto fall.\\n174. Route to the leaves. After entering and traversing\\nthe wood strands of the roots, the water is thence trans-\\nferred along the stem in the same tissues, which are con-\\ntinuous with those of the root. Since the wood strands form\\nan unbroken line to the most remote parts of the leaves,\\npassing out in the ribs and forming the finer veins, the water\\nmay be distributed to every part of the plant body.\\nWithin the wood it travels chiefly in the cavities of the large ducts or\\nvessels, when these are present, though the walls, also, are saturated\\nwith it, and permit a slower movement. These ducts, although of great\\nrelative length (some up to I m. are not continuous tubes like the veins\\nof an animal, nor are they always filled with water. The water is often\\nbroken into short columns by numerous gas-bubbles, and in ascending to\\nany considerable height must traverse many cell-walls.\\nEXERCISE XXV.\\nTo show roughly the path of evaporation stream in woody plants.\\nA. From a leafy shoot of a woody plant remove a ring of bark 5 mm.\\nwide. With grafting wax protect the exposed surface against drying.\\nObserve whether the leaves wilt or not, and if they wilt, the time re-\\nquired.\\nB. With a knife or fine saw cut a little over half through the stem of a\\nplant of the same sort used in A; 1 cm. above this cut make a similar one", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0137.jp2"}, "138": {"fulltext": "132 OUTLINES OF PLANT LIFE.\\non the opposite side. The two must be so placed and at such a depth\\nthat all the tissues are severed. Support the branch or stiffen it against\\nbreaking by bandaging it with strips of wood. Make same observations\\nas in A. Examine the pith. Is it alive Does it contain water In\\nwhat tissues, therefore, do you infer water travels to leaves\\nTo show restoration and maintenance of an interrupted evaporation\\nstream.\\nFit a well wilted shoot into the short arm of an unequal |J-tube filled\\nwith water to the level of the short end. Allow it to stand for half an\\nhour. Does the shoot recover If not, pour mercury into the longer\\narm until it stands 10 cm. above its level in the short arm. Does the\\nshoot now recover turgor Why Allow it to stand for some days.\\nDoes the level of the mercury change\\n175. Motive power. The force by which water is raised\\nin the larger plants remains yet to be ascertained. The water\\ndoes not flow along the ducts in a continuous current, as the\\nblood in the veins, propelled by a force behind, for root\\npressure is not adequate to push it to the height attained.\\nOn the contrary, during the times of most active evaporation\\nfrom the leaves, i.e., when the greatest supply is needed,\\nroot pressure becomes almost or quite negative. Capillarity\\nis also inadequate. The diameter of the largest ducts is too\\nsmall and the resistance to the flow consequently too great to\\npermit the movement, by this means, of a sufficient amount of\\nwater to supply the evaporation. The most recent researches\\npoint to the evaporation of water from the leaves as a very\\nimportant or even the chief factor in lifting the water. That\\nthe movement is not the work of living cells is shown by ex\\nperiments in which stems of plants have been subjected to\\npoisonous agents, or heated for many hours to a degree suf-\\nficient to kill all the living cells, yet without materially affect\\ning the suppl) o water to the leaves.\\nEXERCISE XXVI.\\nTo show tht lifting power oj evaporation.\\nCut off under water a shoot from a thrifty plant fasten it air-tight in\\nthe end of a piece of glass tubing 3G cm. long, ol appropriate diameter,", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0138.jp2"}, "139": {"fulltext": "NUTRITION. 133\\nby means of a piece of rubber tubing slipped over the end of the stem,\\ntaking care not to expose the cut cud to air. Fill glass tube with water\\nbefore fitting in plant erect the whole with lower end of tube dipping\\nin a cup of mercury. Set in light and note height of mercury in I-48\\nhours.\\n176. The loss of water. Water is constantly evaporating\\nfrom the whole surface of the plant exposed to the air. Since\\nthis loss is more or less modified by the vital activity of the\\nplant, it has received the special name, transpiration.\\nEXERCISE XXVII.\\nTo show the loss of water by evaporation.\\nClean and dry the surface of a pot in which a thrifty single-stemmed\\nplant is growing close the hole in the bottom with a cork with a\\nbrush paint the whole surface thickly and evenly with melted paraffin.\\nCut out a piece of stiff paper which will fit around stem and just cover\\nthe soil in pot. Using this as a pattern cut a cover for the soil from a\\nsheet of lead slit the cover from the central hole to circumference ad-\\njust it around plant and cement all cracks with grafting wax.* Weigh.\\nWeigh again at intervals of 24 hours, -for 4 days.\\n177. Transpiration. In the higher plants transpiration\\nfrom the surface is reduced by the waterproofing of the epi-\\ndermis, so that most of it takes place from the surfaces of\\ninternal cells into the intercellular spaces, wherever these\\nexist. Since the intercellular spaces are connected with each\\nother and also, through the stomata, with the outside air,\\nwater vapor is constantly passing off by diffusion (see fig.\\n106). The leaves, affording the largest exposure, are espe-\\ncially organs of transpiration. After they have become fully\\nexpanded no considerable amount of water is lost directly\\nfrom their surfaces.\\nOr the pot may be set in a tin or glass vessel which it fits this may\\nbe covered by sheet rubber tied to the edge and about the stem or the\\nlead cover may be cemented on as above.", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0139.jp2"}, "140": {"fulltext": "34 OUTLINES OF PLANT LIFE.\\nEXERCISE XXVIII.\\nTo show the variation in the rate of evaporation due to the difference\\nin structure of the organ. (See also 339.)\\nCompare as shown by shrinkage or by loss of weight, (a) Through\\ncork tissue and without it. Take two potatoes peel one expose side\\nby side compare day by day. (0) Through skin. Compare in same\\nway two apples, (c) Through stomata. Take three equal leaves of\\noleander of one close the stomata (which are on underside only) with a\\nthin coat of grafting wax, or cocoa-butter melted and brushed on (taking\\ncare not to kill cells by having wax too hot) coat the upper surface of\\nsecond in same way leave third uncovered. Compare day by day.\\n178. Amount and regulation. The amount of transpira-\\ntion, therefore, varies with the structure of the leaf rather\\nthan with its area. The temperature, percentage of moisture\\nin the air and movements of the air affect profoundly the\\nrapidity of transpiration. Hence arises the need of regula-\\ntion by the plant, to prevent excessive loss. The guard cells\\nof the stomata are irritable, so that external conditions affect\\ntheir turgor. If both are turgid, they become curved away\\nfrom each other so as to increase the size of the opening be-\\ntween them. If they are flaccid, the thick ridges along the\\ninner face of each cell straighten them, and so close the\\norifice more or less completely (fig. 105). The presence or\\nabsence of hairs upon the leaves, the existence of stomata\\nupon one or both surfaces, the sinking of the guard cells\\nbelow the general leaf surface, the distribution of the stomata,\\nthe thickening of the leaves, their inrolling (fig. 197), or\\nrevolution, have a decided effect upon the rate of transpira-\\ntion, and may be adapted to regulate it. (See 335 ff.)\\nEXERCISE XXIX.\\nTo show that many leaves are not zvetted by water.\\nImmerse various sorts of leaves in water. Does the water wet the\\nsurface What is the cause of the silvery reflection of light from the", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0140.jp2"}, "141": {"fulltext": "NUTRITION. 135\\nsurfaces of some? What relation does this repulsion of water have to\\nblocking of stomata by rain\\nDemonstration. To show the conditions affecting evaporation.\\nConstruct a potometer as follows Bend the central stem of a J-tube\\nuntil it is parallel with the cross piece. Fit into the lower opening of\\nthe straight leg a capillary tube 30-40 cm. long, with 3 cm. of each end\\nbent at right angles to the main part and in opposite directions. Into\\nthe bent leg fit a shoot of a thrifty plant cut off under water, at the\\nsame time filling the T-tube with water. (To accomplish this, bend the\\nshoot to be cut off so that the place of the cut is submerged in a deep\\npan of water. Fit it in tube without exposing cut surface at all to air.)\\nDip the lower end of the capillary tube in water and allow apparatus\\nto stand until capillary tube fills with water. Remove the water for a\\nmoment and allow a bubble I cm. long to enter time it as it moves be-\\ntween a series of equidistant marks on capillary tube. Try the rate\\nunder various conditions of light, temperature, and moisture acting on\\nshoot.\\nTo show loss of liquid water when absorption is great and evaporation\\nslow.\\nGrow seedlings of wheat or oats until 5-10 cm. high then cover with\\na glass bell for an hour or two. Where do drops of water appear\\nWhy\\nB. Foods in general.\\n179. Foods. In addition to an adequate supply of water,\\nplants require food. To be a food, the material must consist of\\ncertain elements put together in such proportions and in such\\na way that it can be used, either at once or by the expendi-\\nture of comparatively little work upon it, to repair or renew\\nthe living protoplasm. All foods are compounds of carbon\\nwith two to four other elements. The best foods are very\\ncomplex in their construction. Only the smallest and sim-\\nplest plants can live upon the simpler carbon compounds. For\\nmost plants the proper foods are precisely of the same nature\\nas for animals, and though each sort of plant has certain\\nkinds of food which it can use best, it may be fed with many\\ndifferent kinds", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0141.jp2"}, "142": {"fulltext": "13^ OUTLINES OF PLANT LIFE.\\nPlant foods, like animal foods, belong mainly to three groups, carbo-\\nhydrates, fats, and proteids. Examples of the first are the sugars, of\\nwhich grape sugar, fruit sugar, and cane sugar are the commonest\\nstarch, which can be broken up into grape sugar and cellulose, the\\nmaterial of cell-walls. Examples of the fats are olive oil, palm oil, cot-\\nton oil, etc. Proteids are generally recognizable by their property of\\ncoagulating upon application of heat, acids, etc. Examples are the\\nalbumen of white of egg, the fibrin of blood, casein of milk, etc.\\nExamples from plants are abundant, but less generally known. Proteids.\\nalways, and either carbohydrates or fats, or both, must be available in\\norder that a plant may be properly nourished.\\nGreen plants obtain their food chiefly by manufacturing it\\nout of simple materials taken into the plant body from the\\nsoil and air. They are the only living things, so far as\\nknown, which have the power of building up foods out of\\nsuch simple materials as carbonic acid gas and water. They\\nare, therefore, the ultimate source of the food supply of the\\nworld.\\nC. Nutrition of colorless plants.\\n180. Colorless plants. By this really inaccurate phrase\\nare meant plants which do not possess chlorophyll, though\\nsome of them are highly colored by other pigments.\\nThe colorless plants among the thallophytes constitute two\\nlarge groups, known as bacteria and fungi. Among the seed\\nplants, also, are found some de-void of chlorophyll.\\nMany plants possessing chlorophyll show to the eye other\\ntints than green, when other pigments are present in such\\nquantity as to mask the green. This is notably the case with\\nthe so-called foliage plants, in vvhich reds, yellows,\\npurples, and browns are common. (See also 9, 33, 3%.)\\nColorless plants necessarily live either upon the material\\nonce produced by a living being, oftentimes upon its dead\\nand decomposing body, or in company with living organisms.\\nThose which live upon dead bodies, whether these have lost", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0142.jp2"}, "143": {"fulltext": "NUTRITION. 137\\ntheir natural form completely or not, are known as saprophytes.\\nThose organisms which live in association one with another\\nare called symbionts and their relation is known as symbiosis.\\n(See Chap. XXIV.) If one plant preys upon and injures\\nanother living plant or animal, it is called parasite and the\\nbeing which supports it is called its host. (See 44.)\\n181. Saprophytes. Saprophytic bacteria live immersed\\nin solutions of food, or surrounded by films of fluid on the\\nsurface or in the interior of the solid material upon which they\\nflourish. Saprophytic fungi either form their mycelium upon\\nthe surface of the substratum, which contains their food, or, more\\ncommonly, they penetrate it more or less extensively by a pro-\\nfusely branched system of hyphse. A few saprophytic seed\\nplants form at the base of the stem an enlarged, tuber-like mass\\nfrom whose surface great numbers of profusely branched roots\\narise. These penetrate the decaying food material in all direc-\\ntions, and act as absorbing organs. A few have abundantly\\nbranched underground stems and have no permanent roots.\\n182. Digestion. Saprophytes whose surfaces are sur-\\nrounded by food solutions have only to absorb them. Some,\\nhowever, have power to convert into material soluble in\\nwater the solid insoluble food with which they are in contact.\\nThis is brought about in most cases by substances excreted by\\nthe living protoplasm. Such chemical changes, by means of\\nwhich insoluble solid materials are transformed into soluble\\nones and are dissolved, are identical in nature with those\\nwhich occur in the digestive tract of the higher animals, and,\\ntherefore, may be properly termed digestion.\\n183. Assimilation. After the food is absorbed, it under-\\ngoes various changes, collectively known as assimilation, by\\nwhich it is enabled to become part of the living material of\\nthe plant body.*\\nThis is not to be confused with the manufacture of food by green\\nplants, to which the term assimilation is inaptly applied by most writers.", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0143.jp2"}, "144": {"fulltext": "I38 OUTLINES OF PLANT LIFE.\\n184. Parasites obtain their food either by growing upon\\nthe surface of the host and thrusting into its interior absorb-\\ning organs or by growing wholly in the interior of the host,\\nbreaking out to its surface only to form reproductive bodies.\\nParasites may work little apparent harm, or they may bring\\nabout local disease and death of the host. Their mode of\\nobtaining food is not essentially different from that of sapro-\\nphytes. They either digest solid foods, or absorb liquid\\nfoods, prepared by the host for its own use. Among the\\ngreen plants there are some partial parasites, such as the\\nmistletoe, which seem to obtain from their host chiefly the\\nwater and salts which they have absorbed. These materials\\nthey themselves elaborate into food. (See further 370.)\\nD. Nutrition of green plants.\\n185. Raw materials. In order that the green plants may\\nbe able to manufacture their food, they require certain raw\\nmaterials, which are obtained from the water and air. The\\nwater is always a weak watery solution of various mineral salts.\\nFrom the air (or the water in the case of submerged plants)\\nthey absorb a gas, carbon dioxid.\\n186. Salts absorbed. Along with the water which is\\ntaken into the plant go various amounts of dissolved material,\\na considerable portion of which consists of mineral salts.\\nWhen plants grow in humus, or in water or soils containing\\norganic matter, a variable amount of carbon compounds suited\\nfor food may be dissolved by the water and be taken up by the\\nplant. To this extent the plant will live as a saprophyte,\\nand no doubt many field and garden plants have been bred to\\nrequire this sort of life.\\nAmong the mineral salts the most important are the salts of potassium,\\nmagnesium, calcium, and iron, which are present in all soils, in greater\\nor less quantity, and are dissolved in surface waters. In the same way", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0144.jp2"}, "145": {"fulltext": "NUTRITION. 139\\nmain- additional compounds, of no use in forming food, are taken in.\\nThese are all found in the ask, when a plant is completely burned,\\nthough not necessarily in the same form in which they were absorbed.\\n187. Selective action. The compounds which exist in\\nthe water in various, though small amounts are not taken into\\nthe plant in the same proportions as they exist in the water.\\nSubstances which are utilized by the plant and which, there-\\nfore, disappear as such within it by having their chemical\\ncomposition altered or by being stored up in a different form\\nand so removed from solution, will enter the plant contin-\\nuously, as long as the supply outside exists. Substances ab-\\nsorbed and not utilized accumulate in the water inside the\\nplant, and these solutions soon attain the same degree of con-\\ncentration as those outside. Then they are no longer ab-\\nsorbed. It is for this reason that two plants growing upon\\nthe same soil may contain very unequal quantities of any im-\\nportant material. Plants thus exert a sort of selective action,\\nbut this selection is dependent upon purely physical laws, and\\nis only indirectly under the control of the plant.\\n188. Carbon dioxid. Carbon dioxid is a gas, which is\\nalways present in the air, in which, however, it exists in small\\nquantities, rarely exceeding one part in twenty-five hundred.\\nAn abundant supply of it is constantly being returned to the\\nair by the breathing of animals and plants, by burning of fuel\\nand by slow decomposition of dead bodies of plants and\\nanimals. The constant currents in the atmosphere make its\\ndistribution practically uniform. On account of its ready\\nsolubility, this gas also exists in abundance in soil waters and\\nin the larger bodies of water constituting streams, lakes, or\\npools. The water which passes through the soil therefore\\nhas a larger percentage of this gas than the air, sometimes\\ncontaining as much as one per cent.\\n189. Absorption. Water plants readily absorb the dis-\\nsolved gas by such surfaces as are exposed to the water.", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0145.jp2"}, "146": {"fulltext": "HO OUTLINES OF PLANT LIFE.\\nFloating plants have opportunity to obtain it both from the\\nwater and from the atmosphere. Land plants, although their\\nroots are surrounded by a comparatively concentrated solution\\nof carbon dioxid, do not take up appreciable quantities by\\nthese organs. On the contrary, the absorption of this gas\\nseems to depend entirely upon those cells which contain\\nchlorophyll. The stomata, which allow the internal spaces\\nfree communication with the outside air, are important organs\\nfor facilitating the absorption of this gas. Its continued ab-\\nsorption depends upon its continuous removal from the cell\\nsap in the manufacture of food.\\nEXERCISE XXX.\\nTo show the permeability of stomata for air and their communication\\nwith the system of intercellular spaces.\\nFasten a leaf with a long petiole air-tight in a rubber cork, through\\nwhich also passes a short glass tube. Fit the cork into a bottle holding\\nsufficient water to cover end of petiole. Attach a filter-pump or air-\\npump to glass tube. Observe whether air bubbles leave the end of the\\nleaf stalk.\\nReverse the leaf, so that the blade is immersed, and make same ob-\\nservation. Where do bubbles appear Is there any difference between\\nupper and lower sides\\n190. Photosynthesis. The process by which carbohydrate\\nfoods (sugar, starch, etc.) are produced is called photosyn-\\nthesis.* The steps in the process are not thoroughly known\\nindeed they can only be guessed at, and the theories need\\nnot even be stated here. The final product is not neces-\\nsarily the same in all plants, but in many it is cane\\nsugar. Starch appears later in the form of minute granules\\nin the interior of the chloroplasts. It is probably formed\\nas a means of removing some sugar from the cell-sap\\nThis term seems to be more generally approved than photosyntax,\\nwhich was first proposed as a name for this process.", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0146.jp2"}, "147": {"fulltext": "NUTRITION. 141\\nand storing the accumulated food for a time. In all green\\nplants oxygen is a by-product. The amount given off about\\nequals in volume the carbon dioxid used in making the\\nfoods.\\nThe conditions under which photosynthesis occurs are\\nthree (a) the presence of chlorophyll, the action of\\nlight, and (c) the presence of potassium salts.\\nEXERCISE XXXI.\\nDemonstration. 71? show that oxygen is a by-product of photosynthesis.\\nCollect the gas mixture evolved from a vessel full of aquatic plants by\\ninverting over them a funnel to whose tip is connected a test-tube filled\\nwith water to be displaced by the rising gases. Keep the plants in sun-\\nlight. When the tube is filled, test the contents for oxygen by inserting\\na glowing splinter.\\n191. (a) Chlorophyll. Chlorophyll, as has been shown\\nin Part I, sometimes colors the whole protoplasm of the cell,\\nbut is more commonly found only in certain special structures,\\nthe chloroplasts. The real work of forming the food de-\\npends, therefore, upon the protoplasm of the chloroplast.\\nThe purpose of the chlorophyll is to absorb certain portions\\nof the light which falls upon it.\\n192. ib) Light. The light absorbed by the chlorophyll\\nfurnishes the energy necessary to do the work of taking apart\\nthe carbonic acid and rearranging the material into a more\\ncomplex substance. This energy cannot be supplied by the\\nplant itself. An external source of energy is therefore neces-\\nsary. What this source is is unimportant, provided the\\nenergy be sufficient. The light of an electric arc serves the\\npurpose as well as sunlight, if its intensity be equal.\\nEXERCISE XXXII.\\n71? show that manufacture of starch occurs only in cells directly illu-\\nminated.", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0147.jp2"}, "148": {"fulltext": "I4 2 OUTLINES OF PLANT LIFE.\\nDarken portions of some leaves of a plant previously found to show\\nstarch in its leaves (sunflower, bean, tomato, or nasturtium) by attach-\\ning two plates of cork on opposite sides by means of two pins driven\\nthrough both and the leaf. On the afternoon of the following day, ii\\nsunny, cut off the leaves and test for starch as before. What has become\\nof starch in cells under the cork\\n193. (c) Potassium salts. These take no part in the\\ncomposition of the food produced, and their exact role is not\\nunderstood. It is well established, however, that their pres-\\nence is essential to the formation of the carbohydrate food.\\n194. Proteids. The foods thus formed are sooner or later\\nbuilt up into still more complex foods, the proteids. The\\nprocess by which this is accomplished is even more obscure\\nthan the preceding, neither the steps in the process nor its\\nconditions being known. The formation of proteids occurs\\nabundantly in green leaves while they are illuminated, and\\ntherefore making sugar, etc. But even in green plants pro-\\nteids are made in other parts than leaves, and in darkness.\\nThey are also formed by colorless plants. Proteids are used\\ndirectly in the repair of the protoplasm, and for making new\\nprotoplasm.\\nE. Storage and transfer of food.\\n195. Storage and transfer. Both in the colorless and\\ngreen plants it is necessary that the foods should be trans-\\nferred from the point where they are made or absorbed to the\\nplace where they are to be used. The larger the plant, the\\nTo ascertain this, test as follows Boil a few leaves of various plants\\nfor a few minutes. Place in alcohol at about 6o\u00c2\u00b0 C. until all chlorophyll\\nis dissolved. (Do not heat over open flame, but set bottle, loosely corked,\\nin a vessel of hot water.) Bring the leaves into a tincture of iodine,\\ndiluted to a bright brown, for half an hour. The leaves or parts con-\\ntaining starch will become bluish, dark blue, or black, according to\\namount of starch present.", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0148.jp2"}, "149": {"fulltext": "NUTRITION.\\n143\\nmore important (because the longer) does this transfer be-\\ncome. In many plants, also, it is desirable that a supply of\\nreserve food be stored for use when a supply is no longer\\navailable from the outside or by manufacture.\\n196. Storage form. In the higher plants, storage places are secured\\nby the enlargement of roots, stems, and leaves, to form reservoirs.\\nSimilar specialization of parts in the lower plants occurs. The most\\ncommon form of reserve food, especially in thickened stems, roots, etc.,\\nis starch. This is deposited in the form of rounded or oval grains,\\nwhich often show layers due to different composition and density (e.g.,\\nin the potato tuber, A, fig. 114), and are sometimes adherent into com-\\npound grains, e.g., the oat (B, fig. 114). Ins eeds also, much reserve\\nFig. 114.\u00e2\u0080\u0094 Reserve starch. A, two cells of a potato, showing enclosed starch grains.\\nThe other contents not shown. B, compound starch grains from a grain of oats.\\nThree of the component granules of a large grain are shown separately. C, starch\\ngrains from a bean. All highly magnified. After Kerner.\\nfood may take the form of starch, and fats are common. Fats occur in\\nliquid form, as droplets of various size (e.g., cotton seed), and are only\\nrarely solid. In some seeds the cell walls are enormously thickened, so\\nthat the seed is of bony hardness (e.g., the date). Reserve proteids are\\nstored in the form of aleurone grains. These are small granules, often\\npacked in between the larger starch grains, as in the cotyledons of the\\nbean.\\n197. Digestion and transfer. When solid foods, insol-\\nuble in water, are to be moved from one part of the plant to", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0149.jp2"}, "150": {"fulltext": "144 OUTLINES OF PLANT LIFE.\\nanother it must be done by altering them into soluble sub-\\nstances, that is, by digestion. (See ^f 182.)\\nThis is accomplished by means of enzymes of different kinds, adapted\\nto effect the alteration of various foods. The most abundant enzyme is\\ndiastase, which has the power of altering starch into a sugar. Enzymes\\nfitted to transform proteids are also found in considerable amounts.\\nWhen the foods have been brought into a soluble condi-\\ntion, they dissolve in the water present. If one cell rhen\\ncontains more of that particular substance, say sugar, than its\\nneighbor, the sugar particles will pass into the neighboring\\ncells until the amount is equal. If this sugar is being used\\nup in growth or repair, or is altered into another substance\\nat any point, a constant stream of particles of sugar moves\\ntoward the point at which it is disappearing. Thus from\\nthe food sources it is transferred to the reservoirs and stored\\nin suitable form. Thence, when needed, it is redissolved\\nafter digestion and carried to the active parts which utilize it.\\nThis movement may be hastened if elongated cells are pro-\\nvided along the more important lines of travel. This is\\ndone in the bast strands. The movement is made still easier\\nalso in these by the perforation of the ends of some of the\\nelongated cells, so that there is less resistance to movement.\\nFoods, therefore, travel chiefly in the bast bundles and in\\neither direction as may be necessary.\\nEXERCISE XXXIII.\\nTo show in what tissues food most readily travels.\\nGirdle as in Exercise XXV A a shoot of willow. Cut it off 5 cm.\\nbelow ring. Place shoot in water. After some weeks note where new\\nroots are formed. Why\\nTo show the digestion of starch by diastase.\\nPowder a handful of malt in a mortar or obtain ground malt. To 25\\ngrams of the powder add 100 cc. of water stir well together allow\\nmixture to stand (with occasional stirring) one to two hours filter pre\\nserve the filtrate. Take 1 gm. of starch and rub it up in a dish with", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0150.jp2"}, "151": {"fulltext": "NUTRITION. 145\\n5 cc. water pour this into 95 cc. of boiling water, stirring as it enters.\\nWith 25 cc. of this paste mix thoroughly 5 cc. of the filtrate (which con-\\ntains diastase extracted from the malt). Test a small portion of the\\nmixture at once for starch by adding a few drops of tincture of iodine,\\nand similar portions at intervals of half an hour until starch reaction\\nceases. Taste the remaining paste. Into what has the starch been\\nconverted\\nF. Respiration.\\n198. Destructive changes. Coincident with the processes\\nwhich result in the formation of complex foods and from\\nthem still more complex living protoplasm are those which\\nresult in its destruction. In the green plants the construc-\\ntive changes predominate (because of extensive food making),\\nwith the result that the plant accumulates additional organic\\nmatter while in colorless plants destructive processes pre-\\ndominate, with the result that the plant increases in bulk, but\\nonly at the expense of organic materials previously existent.\\nIn all plants, however, both the constructive and destructive\\nchanges go on at the same time and without conflict.\\n199. Respiration. A series of destructive changes is in-\\ncluded under the term respiration. It is a familiar fact that\\nthe higher animals cannot live without a constant supply of\\noxygen and a corresponding excretion of carbon dioxid.\\nThis is not so generally known to be true of plants. It is,\\nnevertheless, true that no plant can live without a constant\\nsupply of oxygen and a corresponding excretion of carbon\\ndioxid. The processes by which (a) oxygen is obtained, (b)\\nunited with the living protoplasm, (c) this substance decom-\\nposed, and {d) carbon dioxid excreted constitute respiration.\\nEXERCISE XXXIV.\\nTo show evolution of C0 2 by respiration of seedlings.\\nFill a wide-mouthed glass jar or bottle of 1 liter capacity one-third full\\nof peas and beans which have been swollen for a day in water, then", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0151.jp2"}, "152": {"fulltext": "146 OUTLINES OF PLANT LIFE.\\nrinsed thoroughly in 5 per cent, formalin and again rinsed in water.\\nCork or cover tightly. After 24-48 hours remove cover and thrust in a\\nburning match or candle attached to a wire. If C0 2 has been produced\\nit will extinguish flame. Test also by lowering into jar a vessel of\\nbaryta-water. If precipitate or film forms it shows presence of C0 2\\nDemonstration. To show evolution of C0 2 by respiration of leaves\\nand fozoers.\\nProvide a piece of plate glass and a bell jar with ground rim, of suit-\\nable size to cover a blooming plant growing in a pot. Alongside the pot\\nplace a shallow dish of baryta-water cover both with the bell, daubing\\nits edge with vaseline to make contact with glass plate air-tight. Place\\nin darkness. Note film of barium carbonate on surface of water after a\\nday. Conduct a control experiment, identical but for the absence of\\nplant. Is more or less barium carbonate formed Why darken\\n200. Respiratory ratio. The ratio between the amount\\nof oxygen consumed and carbon dioxid produced varies\\nsomewhat with the age and condition of the plant, as well\\nas with the circumstances under which respiration occurs.\\nOrdinarily the volume of carbon dioxid produced is approx-\\nimately equal to the volume of oxygen consumed, and the\\nU C0 2\\nratio may be expressed thus 1.\\n201. Respiration and photosynthesis. In the green plants\\nrespiration is masked in daylight by photosynthesis. When-\\never the green parts are sufficiently illuminated, the carbon\\ndioxid produced by their respiration is consumed in the\\nformation of food. But when these parts are not adequately\\nilluminated, the process of photosynthesis is interrupted, and\\nrespiration can be more easily studied. The parts of plants\\nwhich are free from chlorophyll, such as young flowers, buds,\\nembryos, and the like, and all the non- green plants, allow\\nthe respiratory changes to be demonstrated readily.\\n202. Aeration. The oxygen consumed comes from the\\natmosphere, or from that dissolved in water. Certain plants\\nare adapted to aerial respiration, while others are adapted to\\naquatic respiration, but in either case the gas used is the", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0152.jp2"}, "153": {"fulltext": "NUTRITION. 147\\nsame. In the smaller and simpler plants the protoplasm\\nabsorbs oxygen directly through the cell wall. In multi-\\ncellular plants, however, especially when they become large\\nand complex, only the cells at the surface could do this.\\nThe internal cells are too far from the source of supply to\\nallow an adequate amount of oxygen to reach them by travel\\nthrough other cells. In large plants, therefore, internal\\nspaces are provided, and through these oxygen moves readily.\\nIn the land plants the internal spaces open into the air\\nthrough the epidermis, in which, with the guard cells, they\\nconstitute the stomata (*|J 137)- In the absence of stomata,\\nhowever, the oxygen may pass through any part of the sur-\\nface of the plant. In submerged water plants, very large\\nintercellular spaces are formed (fig. 76), permitting the ex-\\nistence of an internal atmosphere of considerable amount,\\nwithin whose limits gaseous exchanges may occur. Oxygen\\nmay reach these intercellular spaces from the water through\\nthe superficial cells.\\n203. Intramolecular respiration. While free oxygen is ordinarily\\nutilized for respiration, all plants seem to be capable of obtaining their\\nsupply for a short time from the living matter of the plant itself. In\\nmost plants it can exist for a few hours at most without producing disease\\nand, sooner or later, the death of the plant. It is precisely parallel to\\nthe similar method of respiration possible among cold-blooded animals.\\nA few plants of the simpler sort, such as the bacteria, rely wholly upon\\ncombined oxygen for their respiratory supply. Such plants have adapted\\nthemselves to grow in the absence of free oxygen, which, instead of\\nfacilitating their life processes, really checks them.\\n204. Excretion. The carbon dioxid produced by respira-\\ntion, when not used for food making, is gotten rid of by\\nthe reverse of the methods described for the absorption of\\noxygen.\\n205. Release of energy. The purpose of respiration is to\\nset free energy required for growth and movement. While", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0153.jp2"}, "154": {"fulltext": "14$ OUTLINES OF PLANT LIFE.\\ncertain plants are capable of utilizing radiant energy of the\\nsun for food making, all must set free within their own\\nbodies the energy requisite for putting in place particles of\\nnew material to form new parts, and for the execution of\\nmovements, whether internal, such as the streaming or rota-\\ntion of the protoplasm, or mass movements, such as those of\\nleaves and other members, or movements of locomotion, such\\nas those of swarm spores and sperm cells. (See ^f 236 ff.)\\nThe required energy is set free by the destruction of the sub-\\nstance formed when oxygen united with the protoplasm.\\nEXERCISE XXXV.\\nTo show the necessity of respiration for growth.\\nGerminate a number of beans in sawdust. Select eight with straight\\nroots about 2 cm. long. Clean and dry the surface slightly by brushing\\nwith frayed edges of strips of filter paper, taking care not to expose roots\\nso long that they are injured by dry air. With a very fine sablehair brush\\nand thick Chinese (or waterproof black drawing) ink, mark each root by\\ndistinct lines into ten spaces I mm. apart, commencing with tip. This\\ncan be done most conveniently by pinning the seedling to a strip of soft\\nwood and laying alongside the root a ruler whose graduated edge has\\nbeen blunted by a plane until it is about 2 mm. thick.\\nPin half the seedlings to a strip of soft wood set into a jar partly filled\\nwith wet sawdust, so that the roots will be vertical in damp air. Put\\nthe other half into a similar jar and cover them with water recently\\nboiled and cooled. After 24 hours, remeasure and compare total growth.\\n(See also Exercise XXXVI.)\\n206. Loss of weight. As a consequence there ensues a\\nloss of weight. If a plant, such as a seedling abundantly\\nsupplied with reserve food, be compelled to develop in dark-\\nness, and so allowed to make no additional food, it may be\\neasily demonstrated that a large part, often as much as one\\nhalf, of its weight will be lost (as gases) in respiration. This\\nloss of weight comes primarily from the decomposition of\\nportions of the living protoplasm. These, however, are soon", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0154.jp2"}, "155": {"fulltext": "NUTRITION. 149\\nreplaced by the formation of new protoplasm from the foods.\\nUltimately, therefore, respiration results in a diminution of\\nthe reserve food.\\n207. A vital function. Respiration is a function of the\\nprotoplasm, and does not occur simply because substances\\nare present in the plant which are destroyed when oxygen is\\nbrought into contact with them, as fuel is in a furnace. On\\nthe contrary, the oxygen seems to enter into loose combina-\\ntion with protoplasm, forming an extremely unstable com-\\npound. This, under unknown conditions, and often some\\ntime after its formation, breaks down into simpler substances,\\nso setting free energy. Some of these materials are again\\nused in building protoplasm, while others break down still\\nfurther, ultimately into water and carbon dioxid. The sup-\\nply of oxygen is so necessary that if a plant cannot obtain\\noxygen from the air or water, it will secure it by the destruc-\\ntion of part of its own substance for a time, thus burning the\\ncandle of life at both ends.\\n208. Heat. While this decomposition of the protoplasm\\nin ordinary respiration is not a true combustion, it neverthe-\\nless results, as combustion does, in the evolution of heat.\\nThe amount of heat produced is usually not great enough,\\nand its loss too rapid, to make it readily perceptible. Any-\\nthing which prevents the loss of heat will make its measure-\\nment possible. The germination of large quantities of seeds\\nor the blossoming of a number of flowers in a confined space\\nmay raise the temperature as much as 15 or 20 above that of\\nthe air.\\nThe heating of hay, grain, and similar substances, which have been\\nstored when moist, is due partly to the respiratory activity of bacteria\\nand fungi, which grow rapidly under these conditions. Fermentation,\\nwhich also occurs under the same conditions, adds largely to the evolu-\\ntion of heat.", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0155.jp2"}, "156": {"fulltext": "150 OUTLINES OF PLANT LIFE.\\nEXERCISE XXXVI.\\nTo show the evolution of heat during respiration.\\nTake three-fifths the amount of dry wheat required to fill two 3 -inch\\nflower pots swell in water over night rinse one half in 5 per cent\\nformalin kill the other by boiling in water for five minutes. Stop bottom\\nhole in pot with a cork fill one with dead, the other with living seeds,\\nand bring the two to same temperature by running water through the\\ndead and hot one. Insert a thermometer in the center of each mass of\\nseeds place both under one box or bell jar. Observe changes of tem-\\nperature for two days.*\\n209. Contrast between respiration and photosynthesis.\\nSince the processes of respiration and photosynthesis in\\ngreen plants are so frequently confused, a contrast is here\\ndrawn between them.\\nRespiration. Photosynthesis.\\nOccurs in all living cells. Occurs only in green cells.\\nIndifferent to or retarded by Requires light.\\nlight.\\nConsumes organic matter. Produces organic matter.\\nProduces carbon dioxid. Consumes carbon dioxid.\\nConsumes oxygen. Produces oxygen.\\nSets free energy. Stores energy.\\n210. Other destructive changes. Besides those constitut-\\ning respiration, a considerable number of other destructive\\nchanges occur, which are not so closely connected with the\\nvital functions of the plant. They result in the production\\nof substances which are of no further use in nutrition and\\nonly of incidental value for any purpose. Such substances\\nmay be stored in some out of the way place or put into such\\nparts as are transient, so that, by the loss of these parts, the\\nCompare thermometers previously to see that they register alike if\\nnot ascertain the correction. Greater differences in temperature of seeds\\nwill be observed if pots are surrounded with cotton batting.", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0156.jp2"}, "157": {"fulltext": "NUTRITION.\\n151\\nuseless materials are gotten rid of; or they may be excreted\\ndirectly. They may be called waste materials.\\n211. Waste materials. Among the most important are the carbon\\nacids, such as oxalic, malic, etc., the tannins, the resins, the gums, the\\nvolatile oils, and the alkaloids. These substances are either by-products\\nof photosynthesis, or they arise in the course of the assimilation of foods.\\nOxalic acid is usually gotten rid of by being combined with calcium to\\nform calcium oxalate, which crystallizes either in the form of squarish\\ncrystals or as long needles (fig. 115). The resins, usually dissolved in an\\noil, are generally excreted into special intercellular spaces. Volatile oils,\\nto which most odors of plants are due, are secreted by glandular hairs\\nfig. 74) or are formed in the epidermis itself, as in flowers or are\\nFig. 115. Fig it6.\\nFig. 115. Crystals found in plants. I, calcium carbonate; II-IV, calcium oxalate;\\nII, octahedron with blunt ends III, compound crystals from the nectary of a mallow\\nIV, a, 6, needle crystals (raphides) from leaf of fuchsia. All highly magnified.\u00e2\u0080\u0094\\nAfter Behrens.\\nFig. x 16. Section through oil-receptacles in rind of orange. The upper figure shows\\nthe structure at the beginning of the disorganization ot the oil-producing cells the\\nlower, the final condition, with two drops of oil occupying the cavity Moderately\\nmagnified. After Tschirch.\\nproduced in chambers near the surface, the cells which produce the oil\\nbeing disorganized to form the cavity in which the drops lie (fig. 116).\\nMany of the alkaloids, such as quinin, morphin, strychnin, nicotin, etc.,", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0157.jp2"}, "158": {"fulltext": "152 OUTLINES OF PLANT LIFE.\\nare important medicines. They occur in the seeds, bark, or leaves, and\\nare gotten rid of when these are dropped.\\n212. Summary. The elements required for the nutrition\\nof plants may be determined by analysis. The chief com-\\npounds are found to be water and carbon compounds. Water\\nand the mineral salts dissolved in it are absorbed by land\\nplants from the soil by means of root-hairs. Since the water\\ntends to become equally distributed through the soil the\\nroots draw their supply of solutions not only from parts with\\nwhich they are in contact, but also from more distant regions.\\nThey are also able to dissolve certain solids. The water ab-\\nsorbed moves into the stele, often under pressure, and is\\ncarried, by unknown forces, to the leaves, through the wood\\nstrands. It is constantly evaporating from the leaves, which\\nregulate the amount in various ways.\\nFoods are required to repair waste and provide for growth.\\nColorless plants must absorb these from solution if the foods\\nare not already soluble they must be made so by digestion.\\nThe foods they use are carbon compounds which have been\\nmade by some other living being. Green plants can use\\nready-made food, or, if suitably illuminated, they can make\\nfoods out of carbon dioxid and water, with small quantities\\nof mineral salts. The carbon dioxid is absorbed from air by\\nthe leaves. Light furnishes the energy for building up the\\nsimple substances into carbohydrates. Proteid foods are\\nalso made by working into the carbohydrates additional\\nnecessary elements. Foods may be used at once or stored,\\nusually in solid forms, for a longer or shorter time. When\\nneeded they are digested and transferred.\\nRespiration of plants is exactly like respiration of animals.\\nIts purpose is to release energy stored in the living proto-\\nplasm to enable it to work, i.e. to grow, move, etc. Respi-\\nration consists in the absorption of oxygen, the decomposi-\\ntion of protoplasm, and the excretion of carbon dioxid and", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0158.jp2"}, "159": {"fulltext": "NUTRITION. 153\\nwater. A considerable amount of food is used to repair the\\nnecessary destruction in respiration. A plant which is not\\ntaking in food from without, or making food, is decreasing\\nconstantly in (dry) weight through respiration. Respiration\\nand other destructive chemical changes incident to work re-\\nsult in the formation of a great variety of products called\\nwaste products because they take no further part in the pro-\\ncesses of repair or growth.", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0159.jp2"}, "160": {"fulltext": "CHAPTER XV.\\nGROWTH.\\n213. Definition. The growth of plants is continued for a\\nmuch longer time than that of animals. In most cases it is\\ncontinued in some part throughout the existence of the plant.\\nThere are also changes in the form of certain parts, particularly\\nof the lower plants, which must be distinguished from true\\ngrowth. Growth is a permanent change of form accompanied\\nusually by an increase in size.\\n214. Formation of new parts. Each new cell originates\\nby the division of some previously existing cell. The two\\ncells so formed grow until they attain the size of the parent\\ncell, when one or both may continue to grow until they at-\\ntain a permanent form then growth ceases. Those cells\\nwhich do not develop into permanent tissue, but retain their\\npower of division, constitute a mass of tissue at the tip of each\\nbranch or root, from which all new parts regularly arise.\\n(If 71, 87). It will be seen, therefore, that every cell of a\\nplant has been at some time in an undeveloped or embryonal\\ncondition.\\n215. Phases of cell growth. The more striking charac-\\nteristics of this embryonal condition are the nearly uniform\\nand small size of the cells, and the absence or small size of\\nthe water spaces (A, fig. 117). As the cells which are des-\\ntined to become the permanent tissues grow older they pass\\ngradually from the embryonal stage into a second phase of\\ni54", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0160.jp2"}, "161": {"fulltext": "GROWTH.\\n155\\ndevelopment, the stage of enlargement. This stage is marked\\nby the rapid increase of the cells in size and a much less\\nmarked increase in amount of protoplasm present. The in-\\ncrease in size, therefore, is mainly due to a great increase in\\nthe volume of water, which accumulates in one or more large\\nspaces (C, fig. 117). If the organ in question has an elon-\\nFig 117 \u00e2\u0080\u0094Cells from young and mature fruit of snowberry (Symphoricarpus), seen in\\nsection A, three young cells, very small, walls thin, nuclei relatively large, vacuoles\\nvery minute; B, two, somewhat older, larger, walls thicker, nuclei smaller, vacuoles\\nseverai. A and B magnified 300 diam. C. a single cell, mature, magnified 100 diam..\\none third as much as A and B vacuole single, very large. 1 he volume of C is more\\nthan 1500 times one of the cells in A. h, cell-wall p, protoplasm k, nucleus;\\nkk, nucleolus s, vacuole.\u00e2\u0080\u0094 After Prantl.\\ngated form, such as the stem or the root, growth of the cells\\ntakes place chiefly in the direction of its long axis. During\\nthis phase the cells may attain a hundred or even a thousand\\ntimes their former volume.\\nEXERCISE XXXVII.\\nTo measure the rate of growth in length.\\nConstruct an auxanometer as follows Take a board 30 cm. square, a\\ncommon spool, a wheat or oat straw 35 cm. long, and a piece of glass\\ntubing 5 cm. long, which will just allow spool to revolve easily on it.\\nClose one end of the glass tube by holding it in the flame of a Bunsen\\nburner; when hot spread it enough to stop spool from passing over end,\\nby pressing it endwise against a piece of iron. With a fine saw cut a\\nsection 5 mm. thick from middle of spool, thus making a wheel. File a\\ngroove in edge of this wheel, deep enough to carry a thread. Slip wheel\\non glass tube and fasten it in board near lower left corner so deep that", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0161.jp2"}, "162": {"fulltext": "56\\nOUTLINES OF PLANT LIFE.\\nthe spool-wheel will revolve smoothly but have no unnecessary play.\\nOn the board, with hole for glass tube as a center, mark an arc of 90 de-\\ngrees. The radius of the arc should be a multiple of the radius of wheel.\\nDivide arc into half centimeters. Attach wheat straw to wheel as a\\npointer.\\nTo the tip of a growing seedling bean fasten a thread by a slip noose\\nPass thread over wheel once and to its free end attach a light weight,\\njust enough to turn wheel and pointer when plant is lifted. Set pointer\\nat o and at intervals read the multiplied growth. By taking observation-\\nat regular intervals determine the rate of growth of stem for a week.\\nWhat regular variation can you discover\\n216. Grand period of growth.\u00e2\u0080\u0094 The entire duration of\\ngrowth of an organ is known as its grand period of growth.\\nThe growth is not uniform, but is at first very slow, increasing\\ngradually, and then more rapidly, to a maximum, from which\\nit falls rapidly, and then more gradually, until it ceases en-\\ntirely. The accompanying curve (fig. 118) represents the\\n2V\\nt s\\nt\\n4 V\\nt s\\nr A\\n7 V\\nt S^\\n4 S^ _Z\\nt ^v\\nJ\\n7 N\\nU 4 8 12 16 20\\nFig. 118. Curve representing the rate of growth ot an internode of crown imperial for\\neach day during the grand period\u00e2\u0080\u0094 in this case 20 days. The height ot each vertical\\nline where it intersects the curve represents the total growth for the corresponding 24\\nhours. The numbers indicate days. The maximum growth occurred on the 6th day\\n\u00e2\u0080\u0094After Sachs.\\ncourse of growth in length of a short section of a stem.\\nGrowth, however, is not uniform from day to day or from hour\\nto hour. If the line should be drawn so as to show these\\nvariations it would be irregularly zig-zag, but would follow\\nthe same general course as the smooth curve. (See ^j 222.)", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0162.jp2"}, "163": {"fulltext": "GROWTH.\\n157\\n217. Growing region. The part of any one of the\\nlarger plants which is growing in length is limited. The\\nelongating region of a root rarely\\nexceeds a centimeter, and is often\\nnot more than one-half a centi-\\nmeter in length. In stems, how-\\never, the elongating part may\\nmeasure twenty or even fifty cen-\\ntimeters, and in rare cases much\\nmore. Figure 119 shows a root,\\nA, upon whose surface marks were\\nmade 1 mm. apart. Twenty-four\\nhours later the root presents the\\nappearance of B. Only the tis-\\nsues in the first five spaces were\\ncapable of elongation. The\\nothers had passed into the third\\nphase. The second and third\\nmillimeters grew most in length.\\nThe growing regions of stems may\\nbe determined in the same way.\\nEXERCISE XXXVIII.\\nTo determine the zone of maximum Fig. tiq.\u00e2\u0080\u0094 A, a young root of the pea\\ngrowth inroots and stems.\\nA. Arrange four seedlings as in\\n5[ 205, with roots vertical, in moist air.\\nWhich spaces grow most?\\nB. Mark several upper internodes\\nof a bean plant in a similar way, but\\nat 5 mm. intervals. After 48 hours observe how many have elongated\\nand which have grown most.\\n218. Tension due to growth. The different regions in\\nany organ usually do not grow at an equal pace, and con-\\nsequently certain parts are under strain, while others are\\ncompressed. The curled and crinkled leaves or the curved\\nink into 13 spaces of 1 millimeter\\neach. B, the same root, 24 hours\\nlater, showing elongation only in\\nterminal 5 millimeters. The rate of\\ngrowth is greatest in the ?.d and 3d\\nmillimeters, and slow in the 1st, 4th,\\nand 5th. Magnified 2 diam.\u00e2\u0080\u0094 After\\nFrank.", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0163.jp2"}, "164": {"fulltext": "158 OUTLINES OF PLANT LIFE.\\ncapsules of mosses illustrate this inequality. It may be pres-\\nent, however, without manifesting itself in the external form.\\nIf the rapidly growing flower-stalk of the dandelion or the leaf-\\nstalk of rhubarb be carefully split lengthwise the parts will\\ncurve or even curl outward. Separating the pith and the\\ncortex of a young elder shoot from the wood and carefully\\nmeasuring them shows that the pith elongates and the cortex\\nactually shortens. The experiment, therefore, shows that the\\npith really grew more rapidly than wood, but were com-\\npressed in the uncut stem, while the cortex was slightly\\nstretched. The strains thus set up are spoken of as longitudi-\\nnal tensions. Similar tensions due to unequal transverse\\ngrowth may be shown to exist. If a thin transverse slice\\nfrom the fleshy leaf-stalk of the rhubarb be divided into\\nequal parts by a longitudinal cut it will be found in a few\\nmoments that the halves can no longer be made to touch\\nthroughout the line of the cut, because it has become convex.\\nBoth sorts of tensions will be exaggerated if the parts be\\nplaced for a few moments in water.\\nEXERCISE XXXIX.\\nTo show the existence of longitudinal tensions of tissues due to unequal\\ngrowth or turgor.\\nA. Cut a young internode of elder 10 cm. long, making ends as square\\nas possible. Measure accurately. Remove wood all around and meas-\\nure pith. Place pith in an atmosphere saturated with moisture and re-\\nmeasure after 1 hour. Compare measurements. (If elder is not at hand\\nuse young shoots of grape, wild or cultivated.)\\nB. Split a scape of dandelion lengthwise with a sharp knife into four\\nstrips. Note immediate effect upon their form. Lay the strips in water\\nfor a few minutes. Observe form. Transfer them to 5 per cent salt so-\\nlution. What effect? What causes these changes of curvature (The\\nyoung stems (hypocotyls) of castor bean may be substituted for dandelion\\nscapes, but are not so responsive.)\\nTo show the existence of transverse tensions of tissues due to unequal\\ngrowth.\\nA. From a piece of willow or poplar stem separate a ring of bark 1 cm.", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0164.jp2"}, "165": {"fulltext": "GROWTH. 159\\nwide, slitting it on one side only, taking care not to stretch it. Keep\\nit in a moist atmosphere for a few minutes, and then replace it. Does\\nit meet about the wood\\nB. Cut a slice about 2 mm. thick from the end of a stalk of rhubarb.\\nBisect this and keep the halves for a few minutes in a moist atmosphere,\\nthen place severed edges together. Do they touch throughout?\\n219. Conditions of growth. That plants may grow cer-\\ntain conditions are prerequisite. (1) There must be an\\nadequate supply of constructive materials. These may be de-\\nrived either from food recently manufactured or from that\\nstored in reservoirs, or, in the case of the colorless plants,\\nfrom that absorbed from without. (2) There must be a\\nsupply of oxygen for respiration. This is needed, as previously\\nexplained, to set free the energy necessary for growth. (3)\\nThere must be a supply of water adequate to supply the mate-\\nrial for filling the cells during the phase of enlargement.\\n(4) A suitable temperature is required. The range of tem-\\nperature within which growth may take place is extensive,\\nand varies with the individual plant. In general, the upper\\nlimit may be stated as about 40 C. and the lower about o\u00c2\u00b0 C.\\nThe minimum of plants of tropical regions is approximately\\nio\u00c2\u00b0 C, while the maximum for plants of the arctic or alpine\\nregions is much below 40 C. Between the maximum and\\nminimum temperatures there is an optimum temperature for\\neach plant, at which growth takes place most rapidly. For\\nmost plants the optimum lies between 25 and 32 C.\\n220. External conditions exercise a very important influ-\\nence upon the rate or character of growth by reason of the\\nirritability of the protoplasm. (See further 317.) Many\\nof these conditions act upon members of the plant so as either\\nto bring about permanently unequal growth in a certain part,\\nor to cause one part to grow more or less rapidly for a time\\nthan another. Such variations in growth produce curvatures\\nin the parts concerned and move members connected with\\nthem. They are discussed in the chapter on Movements.", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0165.jp2"}, "166": {"fulltext": "l6o OUTLINES OF PLANT LIFE.\\nThose conditions which act more generally and uniformly upon\\na large number of plants serve to determine the form and\\nmode of development of members.\\n221. Light. The effect of light on growth is different in\\ndifferent plants and even in different members of the same\\nplant. In general light retards growth in length. Stems\\ngrown in darkness usually become excessively elongated.\\nThose which under normal illumination have very short in-\\nternodes, in diminished light may have them well developed,\\nas occurs, for example, in dandelions growing in deep shade.\\nIn general, light accelerates the growth of leaves in area.\\nLeaves of shoots grown in darkness remain small.\\nLight affects not only the external form but the internal\\nstructure. The difference in structure between the upper and\\nlower surface of the thallus of Marchantia 52, fig. 38) and\\nof the leaves of higher plants (fig. 106) is due to the greater\\nillumination of the upper surface. In diminished light cell\\nwalls may not thicken normally, and mechanical tissues are\\nweakened. Lodging of oats and such grasses is mainly\\ndue to this cause (fig. 120.)\\n222. Light and temperature. The combined variation\\nof light and temperature between day and night establishes a\\ndaily period in the growth of all plants. The withdrawal of\\nlight at night permits an increase in the rate of growth in\\nlength, which reaches its maximum in some plants shortly\\nafter midnight, in others not until the early morning. During\\nthe day its retarding effect diminishes the rate of growth,\\nwhich reaches a minimum some time in the afternoon. The\\nminor fluctuations in temperature, as well as the generally\\nhigher temperature during the day and lower during the night,\\nintroduce variations in the rate of growth, which obscure, but\\ndo not counteract, the retarding influence of light. (See fig.\\n121). This daily period is so impressed upon the constitu-\\ntion of the plant that it maintains it for a considerable time", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0166.jp2"}, "167": {"fulltext": "GROWTH.\\n161\\nCnoti\\nFig. i 20.\u00e2\u0080\u0094 Part of the transverse sections of the stem of rye. A, from a plant grown\\nfully exposed to light: B, from a laid plant imperfectly exposed to light.\\nepidermis b, c, mechanical tissues d, thin-walled tissues.\\nKoch.\\nHighly magnified.\u00e2\u0080\u0094 After\\nT\\n2,0 mm\\n1,5\\n1,0\\n0,5\\n9 11\\nN\\n11 1\\nM\\n3 5 7 9\\nFig. 121. Curve showing the daily period in the growth of a stem of rye. The vertical\\nlines represent 2-hour periods from 5 p.m. of one day to 5 a.m. of the second day,\\nthe shaded parts indicating the actual hours of darkness. The horizontal lines repre-\\nsent tenths of a millimeter. The curve is drawn by taking the record from an aux-\\nanometer and laying off on the vertical line for each interval the growth shown. The\\npoints are then ioined. It will be observed that the maximum rate of growth occurs\\nshortly after the period of darkness (5 a.m.) and the minimum rate after the period of\\nmost intense illumination (5 p.m.). During the experiment the thermometer varied\\nfrom 18 to 22 C\u00e2\u0080\u0094 After Frank.", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0167.jp2"}, "168": {"fulltext": "162 OUTLINES OF PLANT LIFE.\\neven when kept in complete darkness. Stems of sunflower\\nafter two weeks in complete darkness still showed distinctly\\nthe daily period.\\n223. Moisture and oxygen. The amount of moisture\\nand oxygen present in the medium surrounding a plant pro-\\nfoundly affects its form. Amphibious\\nplants, that is, those which are capable\\nof growing either on land or in water,\\noften show this in a striking way.\\nWhen grown submerged, the leaves\\nare usually finely divided, while the\\nsame leaves, if allowed to develop in\\nthe air, have broad blades scarcely\\nmore than lobed (fig. 122).\\nfig. 122 -a shoot of water 224. Mechanical pressures or\\ncrowfoot (Ranunculus\\naguatiiis) The lower leaves strains also exert an influence upon\\nhave developed under water r\\nand are branched into many trie rate and mode of STOWth. Coni-\\nnarrow divisions the two\\nupper leaves have developed pression of tissues retards their growth\\nin air and at maturity float r\\non the surface of the water, strains accelerate it. Thus, stems en-\\nAbout half natural size.\u00e2\u0080\u0094\\nAfter Frank. closed in plaster casts or ligatured grow\\nmore slowly in thickness. Tensile strains, such as those exerted\\nby wind or weight, promote the development of mechanical\\ntissues. Petioles, which would break under a strain of 700 gm,,\\nafter enduring a pull of 500 gm. for five days, broke only at\\n1600 gm. After five days more under a strain of 1200 gm.\\nthey could not be broken with less than a weight of 6500 gm.\\n225. Variations in rate. There are not only variations\\nin growth in the course of each day throughout the growing\\nperiod, but also minor variations independent, so far as\\nknown, of external conditions, which are therefore called\\nspontaneous variations. Irregular variations occur from hour\\nto hour in the course of the day. Regular spontaneous vari-\\nations, also, occur in various organs, particularly in the ten-\\ndrils of climbing plants, and in the leaves of flowers and buds.\\nThese regular variations, which affect different sides of flat-", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0168.jp2"}, "169": {"fulltext": "GROWTH. 163\\ntened organs and different sectors of cylindrical ones, bring\\nabout a bending of the entire organ from one side to another.\\nThese curvatures produce nutation, and will be further de-\\nscribed under movements. (See 241.)\\n226. Duration. Even when the external conditions of\\ngrowth are kept as uniform as possible, growth does not con-\\ntinue for an indefinite time. Having passed through the\\nphases above named, it ceases, no matter how favorable the\\nexternal conditions. Yet some organs, even after growth has\\nceased, may resume it, under certain circumstances. Thus,\\nthe leaf cells which have long since ceased to divide may re-\\nsume the power of division in the neighborhood of a wound,\\nand by division and the growth of new cells may form a scar\\ncovering the wound. The formation of fruits of the seed\\nplants is also a case of resumption of growth after an appro-\\npriate stimulus. (See 306.)\\n227. Summary. Growth is permanent change of form\\nand increase in size. Every part passes successively through\\nthree stages of growth, the first marked chiefly by the forma-\\ntion of new cells, the second by the enlargement of cells al-\\nready formed, and the third by the acquisition of mature\\ncharacters by these cells. The second stage is the stage of\\nvisible and measurable growth. Only a very short part of\\nthe root and a limited region of the stem is growing in length.\\nDuring the stage of enlargement the growth is not uniform.\\nThe rate varies on account of internal (unknown) and exter-\\nnal (known) causes. Among the latter are light and heat.\\nLight generally retards growth in length, but promotes the\\ngrowth in area of leaves and other broad parts. It may also\\nproduce changes in structure as well as form. Rising tem-\\nperature (up to a limit) hastens growth falling temperature\\nretards it. Combined effects of light and heat produce a\\ndaily fluctuation in growth. Pressure, amount of water, and\\noxygen also affect growth. Growth may be resumed by\\nmature parts.", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0169.jp2"}, "170": {"fulltext": "CHAPTER XVI.\\nTHE MOVEMENTS OF PLANTS.\\n228. Irritability. Among the inherent properties of\\nprotoplasm are irritability and automatism. We know prac-\\ntically nothing of the nature of either of these properties,\\nthough upon them depend all the activities of plants. They\\nseem to be merely two phases of the same property. Auto-\\nmatism is the name given to the ability of protoplasm to in-\\nitiate internal changes without the action of any external\\nforce. Irritability expresses the power of the protoplasm to\\nrespond or react to the influence of an external change.\\n229. Stimuli. The external change which brings about\\nthe reaction is known as a stimulus, and its application is\\ncalled stimulation. External forces which may act as stimuli\\nare light, heat, gravity, moisture, electricity, chemical sub-\\nstances, etc. Most of these act constantly in some measure\\nupon plants. In order that they may act as stimuli, there-\\nfore, a change in their intensity or direction must occur. If\\nthe change be great or sudden, the reaction is likely to be\\nmore marked. Sometimes, however, a slow change will still\\nproduce a distinct reaction. For example, the gradual with-\\ndrawal of light may cause movements of leaves. (See 255.)\\n230. Conditions limiting irritability. Protoplasm is ir-\\nritable only under certain conditions, which coincide in the\\nmnin with those that promote the general well-being or life\\nof the organism. But the limits of temperature, moisture,\\n164", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0170.jp2"}, "171": {"fulltext": "THE MOVEMENTS OF PLANTS. 1 65\\nand the supply of oxygen, which permit irritability, are much\\nnarrower than those which permit life. Thus, irritability\\nmay be lost when the conditions are unfavorable, though life\\nmay persist under such conditions for a longtime. Irritabil-\\nity may also be lost through fatigue, as when, after repeated\\nreaction, no response occurs even to a greatly increased\\nstimulus. Upon the return of suitable conditions, or after\\nsufficient rest, irritability may be regained.\\n231. Reaction. The response of the protoplasm to a\\nstimulus is out of all proportion to the physical or chemical\\naction of the stimulus itself. The action of the stimulus upon\\nthe irritable protoplasm may be roughly compared to the\\naction of the trigger upon a primed and loaded gun. It\\nsets free forces vastly in excess of those which it exerts.\\n232. Reaction time. The observable reaction does not\\nfollow instantly upon stimulation. The interval, which is\\nknown as the reaction time or the latent period, is ordinarily\\nmuch longer in plants than in the higher animals. In ex-\\ntreme cases no reaction may be manifest until several hours\\nafter stimulation. In other cases, however, as in the well-\\nknown sensitive plant, the movements of the leaves follow\\nalmost instantly upon stimulation.\\n233. Form of reaction. The character of the reaction is\\nnot dependent upon the nature of the stimulus, but upon the\\nnature of the organ itself. It is not in the least understood\\nwhat the inherent peculiarities are which determine the form\\nof the reaction. In different organs exactly opposite effects\\nmay be produced by the same stimulus, and the same organ\\nat different ages may respond differently to the same stimulus.\\nThus the young internodes of the Virginia creeper (A??ipe-\\nlopsis) are sharply recurved, but become erect when older.\\nThe stalk bearing the flower of the peanut is erect, but as it\\nbecomes older it becomes strongly reflexed, and thrusts the\\nfruit under ground.", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0171.jp2"}, "172": {"fulltext": "1 66 OUTLINES OF PLANT LIFE.\\n234. Localization of irritability. In multicellular plants\\nirritability to certain stimuli is usually localized in certain\\norgans, and often in special parts of these organs. In many\\ntendrils, for example, the free end is curved and only the\\nconcave side is irritable to contact. In the Venus fly-trap,\\nalthough the whole leaf moves at the contact, only the three\\nhairs upon the upper face of each lobe are sensitive to a\\ntouch. (See figs. 224, 137.)\\n235. Transmission of impulse. In these cases, as in many\\nothers, the effect of the stimulus must be transmitted in some\\nway from the point of application to the cells which produce\\nmovement. At present it is not known how this is accom-\\nplished.\\nThe movements of plants may be conveniently considered\\nas (1) movements of protoplasm itself; or, (2) mass move-\\nments of multicellular members of the higher plants.\\nI. Movements of protoplasm.\\n236. Naked cells. Plants which consist of a single cell\\nmay be either naked or furnished with a cell wall. If naked,\\nthey may exhibit either amoeboid ox ciliary movements. Amoe-\\nboid movements are slow creeping movements brought about\\nby the protrusion of a portion of the protoplasm toward\\nwhich the remainder gradually flows (fig. no). Ciliary\\nmovements are due to the extension of one or more very\\nslender threads, called cilia, whose rapid bending in different\\ndirections propels the organism (fig. 109). According to\\nthe nature of the movements, the course will be zigzag or\\nsteady, accompanied by the rotation of the cell on its axis.\\nWhen the cell comes to rest the cilia are either withdrawn or\\ndrop off.\\n237. Cells with a wall. Movements of locomotion in\\nplants possessed of a cell wall are either ciliary or creeping.", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0172.jp2"}, "173": {"fulltext": "THE MOVEMENTS OF PLANTS.\\n167\\nA\\nThe latter are usually due to the protrusion of portions of the\\nprotoplasm through slits in the wall, as in some diatoms\\n(fig. 11). The filaments of the water slimes bend from side\\nto side, and so creep over wet surfaces very slowly (fig. 7).\\nBacteria (fig. 9) and some diatoms move by means of cilia.\\nThe direction of all these movements maybe so controlled\\nby stimuli that the organisms move toward or\\naway from the source of stimulus. Thus, ciliated\\nspores of algae (fig. 109) swimming in a dish of\\nwater, will gather next the lighter side.\\n238. Streaming and rotation. In multicel-\\nlular organs it is common to find the protoplasm\\nwithin each active cell moving about from point\\nto point within the cell. The protoplasm is\\nfilled with numerous large vacuoles, so that it\\nforms a next layer the wall, with threads or\\nribbons extending across it (fig. 123). When\\ncurrents start along the wall and through the\\nstrands, the motion is designated as the stream-\\ning of the protoplasm. These currents along\\nany particular portion of the protoplasm may\\nrun side by side and in opposite directions.\\nWhen the protoplasm surrounds a single\\nlarge vacuole (fig. 117, C), the whole mass cenlrom a hai?of\\nC h e 1 1 do niii m.\\nmay rotate, usually in the direction of its long The arrows show\\nr,,, the direction of\\naxis. I he portion immediately in contact\\nwith the wall is motionless, and there must\\nnecessarily be a strip between the half moving\\nup and the half moving down the cell, which\\nis also quiet. Such movements are called\\nrotation of the protoplasm. It is not known\\nwhether either streaming or rotation has any immediate re-\\nlation to the well-being of the cell.\\nIn addition to the mass movements of the protoplasm, the\\nmovement of the\\nprotoplasm in the\\nperipheral layer\\nand in the bands\\nwhich separate the\\nvacuoles, n. the\\nnucleus, with nu-\\ncleolus. Highly\\nmagnified. After\\nDippel.", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0173.jp2"}, "174": {"fulltext": "1 68 OUTLINES OF PLANT LIFE.\\nsmaller protoplasmic bodies within the cell, such as the\\nnucleus and the chloroplasts, are capable of moving about.\\nII. Movements of multicellular members.\\n239. Forces. The movements of multicellular parts may\\nbe brought about either by special organs known as motor\\norgans, or by the unequal growth of the immature parts.\\nMotor organs are generally responsible for the movements of\\nmature parts, while movements of the younger regions are\\ngenerally due to growth. The force exerted by the motor\\norgans is dependent upon the altered turgor of the cells of\\nwhich the organ is composed. If the cells upon one side of\\nit lose their turgidity, those upon the other, being unresisted,\\nwill extend and bend the organ toward the side upon which\\nthe turgor was diminished. It will be convenient, therefore,\\nto distinguish movements due to growth and movements due\\nto variation in turgor.\\n240. (A) Movements of growth. These depend upon\\nsome inequality in the rate of growth of the organ concerned.\\nThey are of two sorts, (i) Those in which variation in\\ngrowth is produced by causes not yet known (apparently in-\\nternal) are called spontaneous movements. (2) Those in\\nwhich the variation in growth results from stimulation by\\nexternal agents are called paratonic movements.\\n241. 1. Spontaneous movements. Among spontaneous\\nmovements are those in which the variation in growth occurs\\nupon different sides of a cylindrical organ, or the two faces\\nof a broad one. The opening of all flower and leaf buds\\nillustrates this movement, which is called nutation. During\\nthe development of the interior parts, the outer leaves (often\\nscale-like) which protect them grow more rapidly upon their\\nouter (dorsal) surfaces. They are thus pressed together into\\na compact bud. When the internal parts are suitably de-", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0174.jp2"}, "175": {"fulltext": "THE MOVEMENTS OF PLANTS. 1 69\\nv eloped a change occurs in the rate of growth of the outer\\nleaves; their inner (ventral) faces now grow more rapidly\\nand the bud expands. Similar spontaneous variation in the\\ngrowth of different sides of tendrils produces a nodding or\\nwaving motion, or even a rotation of the tip, by means of\\nwhich they are often enabled to reach a support. In most\\ntendrils the region whose growth is hastened travels irregu-\\nlarly around the axis, so that their tips rotate in a roughly\\ncircular or elliptical orbit from the time the tendril is two-\\nthirds grown until growth ceases. The further changes in\\nthe tendril, by which it wraps the tip about the support and\\ncoils the remainder into a double spiral, are paratonic move-\\nments induced by contact. The rotating movements by which\\ntwining plants climb are also paratonic and not spontaneous.\\n242. 2. Paratonic movements are also of the highest im-\\nportance for the well-being of the plants concerned. By\\nmeans of them the different organs are developed in such\\nsituations that they can properly perform their work. The\\nstimuli which influence the rate of growth are chiefly light,\\ngravity, heat, mechanical contact, and moisture. The pecul-\\niar states in which a plant or an organ exists when it can\\nrespond to the different stimuli have received different names,\\nand those names indicate the nature of the stimulus. A\\nplant or an organ i S heliotropic when it places itself in a cer-\\ntain position with reference to the direction of the rays of\\nlight falling upon it geotropic, when it reacts thus to the\\nforce of gravity; thermotropic, when it reacts thus to the\\npresence of a warm body hydrotropic, when it reacts thus to\\nthe presence of a moist surface, etc. In each case the plants\\nare said to react positively when the movement is toward the\\nsource of the stimulus negatively, when the movement is\\naway from the stimulus transversely, when it is transverse to\\nthe direction of the stimulus. These reactions are to a cer-\\ntain extent related to one another, and it will be convenient,", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0175.jp2"}, "176": {"fulltext": "170\\nOUTLINES OF PLANT LIFE.\\ntherefore, to consider the effect of each stimulus upon the\\ntwo common forms of plant organs namely, the radial (such\\nas stems and roots) and the flattened (such as leaves).\\n243. (a) Heliotropism. Heliotropism is the state of a\\nplant or organ when it is irritable to the direction of light\\nrays. Light thus plays an important part in determining the\\nposition of organs. As a rule radial organs are either posi-\\ntively heliotropic, as the stems and leaf-stalks, or negatively\\nheliotropic, as the roots. In ordinary light leaves are all\\ntransversely heliotropic, assuming a position at right angles\\nto the direction in which the light comes. This is the most\\nfavorable position possible for the manufacture of food by\\nthe green parts (fig. 124). Intense light, however, may\\nn n\\nFig. 124.- Diagrams representing the transverse heliotropism of leaves of the garden\\nnasturtium Trofatoluvi). Potted plants were subjected successively to light strik-\\ning them in the direction shown by arrows. The petioles curved so as to place the\\nblades at right angles to the incident light.\u00e2\u0080\u0094 After Vochting.\\nbring about a different reaction, so that the leaves set them-\\nselves edgewise to the light. A fixed light position is usually\\nreached by leaves by the time they become mature, and this\\nis generally at right angles to the source of greatest light.\\nBranches of trees show the leaves so arranged as to size and\\nposition that they shade each other as little as possible, form-\\ning the so-called leaf mosaics (figs. 125, 126). The leaves of\\nwindow plants also exhibit these movements very strikingly,", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0176.jp2"}, "177": {"fulltext": "THE MOVEMENTS OF TLA NTS.\\nbecause usually illuminated from one side,\\ndarkness have their leaves irregularly placed.\\n171\\nPlants kept in\\nFig. 125. Leaf mosaic formed by a horizontal shoot of Norway maple. The lengthen-\\ning of the petioles of individual leaves to avoid shading of tfhe blade is marked.\\nAbout one-third natural size.\u00e2\u0080\u0094 After Kerner.\\nFig. 126. A rosette of leaves of a bellflower (Campanula fiusilld), showing length-\\nening of petioles of lower leaves so as to carry blades from under upper leaves.\\nAfter Kerner.\\nEXERCISE XL.\\nTo show the effect of direction of light as a stimulus on leaves.\\nSet a potted plant (geranium, sunflower, nasturtium, or mallow) in the\\ndark for 24 hours; then place it before a window, shading it so that", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0177.jp2"}, "178": {"fulltext": "172 OUTLINES OF PLANT LIFE.\\nlight reaches it chiefly from one direction. Mark certain leaves and\\nrecord the position of the plane of the blade 24 hours later observe the\\nposition and compare with first.\\nTo show effect of direction of light as a stimulus upon stems and roots.\\nGrow seedlings of white mustard thus: Tie loosely over the mouth of a\\njelly-glass a double piece of fine bobbinet fill vessel with tap water to\\nthe net, on which place seeds; set in dark, replacing water as it evapo-\\nrates, until seedlings are 3 cm. high, with roots as long or longer. Then\\nplace in a box, blackened inside, into which light is admitted through a\\nhole 4-5 cm. in diameter, at right angles to stems and roots. Observe\\ncurvatures 24 hours later.\\n244. (b) Combined movements due to variations in the\\nintensity of light or heat or both are especially exhibited by\\nflowers, whose opening and closing are frequently determined\\nthereby. With some plants the predominant stimulus is\\nheat with others, light. Closed flowers of the tulip or\\ncrocus may be made to open in 2 to 4 minutes by raising the\\ntemperature 15 to 20 The flowers of the white water-lily\\nand of the dandelion open in sunlight and close in shade.\\nBy marking upon their leaves a series of equidistant parallel\\nlines with Chinese ink, and measuring later the distances to\\nwhich they have been spread, all such movements can be\\nclearly shown to be due to accelerated growth of the outer or\\ninner surfaces, respectively. The protection of the flower\\nparts or their proper working is secured by these movements,\\nwhich must not be confounded with those due to the direction\\nof light or heat rays.\\n245. (c) Geotropism. Geotropism is the state of a plant\\nor an organ when it is irritable to the force of gravity.\\nSince gravity is exerted always in the same direction, it is\\nplain that reactions to this force cannot be studied, as in the\\ncase of light, by altering the absolute direction in which\\ngravity acts, but only by so changing the position of the\\nplant that the force acts in a relatively different direction.\\nThe reaction to this stimulus and the fixed gravity position\\nmust not be confused with the simple effect produced by the", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0178.jp2"}, "179": {"fulltext": "THE MOVEMENTS OF PLANTS.\\n173\\nweight of the parts concerned. Such effects are to be seen\\nin the downward bending of some plants with slender\\nbranches, or the curvature of the flower or fruit stalks by the\\nweight of the parts. True geotropic curvatures are brought\\nabout by acceleration of the growth of the irritable cells, and\\nthe curvatures produced may even be contrary to the direc-\\ntion of the force. If seedlings be grown in boxes upon the\\nrim of a wheel rotating slowly in a vertical plane, so that\\nthey are successively subjected to the action of gravity in\\nrelatively different directions, it will be seen that while their\\nFig. 127.\u00e2\u0080\u0094 Seedling mustard plants grown on a cube of peat, 7, attached to the slowly\\nrotating axle, A, A, of a clinostat. The direction of growth of roots and stems is\\ncontrolled only by the nearness of moist surfaces, the action of gravity and light being\\neliminated. Note the variable direction of roots and stems. At m and r// 2 aerial\\nhyphae of a mold have taken direction as far from the repellant moist surfaces as pos-\\nsible. One half natural size. After Sachs.\\nmembers grow in nearly straight lines, the direction assumed\\nby the stems and roots is quite as frequently abnormal as\\nnormal, because the effect of gravity which normally deter-\\nmines the direction of growth of these axes is neutralized,\\nsince it now acts upon them from a new direction at each\\nsuccessive moment (fig. 127). If the wheel upon which\\nsuch seedlings are grown be rotated at a high speed, the cen-", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0179.jp2"}, "180": {"fulltext": "174\\nOUTLINES OF PLANT LIFE.\\ntrifugal force will become a constant one, and, acting in\\nplace of the neutralized force of gravitation, will determine\\nthe direction which the stems and roots will assume. Since\\nthe primary stems of most plants are negatively geotropic,\\nwhen grown under such conditions they will turn toward the\\ncenter of the wheel, while the positively geotropic roots grow\\ntoward the rim. Similarly, if the wheel be rotated rapidly\\nin a horizontal plane the parts will be controlled by a com-\\nbination of the force of gravity and the centrifugal force (the\\nlatter predominating if the speed is great) the stem will\\ngrow inward and upward, while the roots will grow down-\\nward and outward (fig. 128).\\nFig. 128.\u00e2\u0080\u0094 Part of centrifuge, a, the axle, rotated at a high speed by water or electric\\nmotor, to which is attached the circular metal piate, r, r, carrying a disk of cork, k.\\nTo the latter are attached two seedling beans, A B, by means of pins st, the primary\\nstem h, the primary root. Ovc the seedlings the cover, is placed to keep them\\nmoist. After a few hours the lateral roots have turned into the direction of the cen-\\ntrifugal force, which was sufficiently powerful to overcome that of gravity except near\\naxis of rotation, x. One halt natural size. -After Sachs.\\nEXERCISE XLI.\\nTo show the effect of gravity as a stimulus on roots.\\nArrange the marked root of a seedling bean as in 205, except that\\nthe root is horizontal, and a pin just above the extremity marks its posi-\\ntion. After 24 hours observe curvature and which spaces have become\\ncurved. Compare with those which have grown most.\\nTo show the effect of gravity as a stimulus on growing regions of upright\\nleaves.", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0180.jp2"}, "181": {"fulltext": "THE MOVEMENTS OF PLANTS. 175\\nSupport an onion, roots down, in a vessel of water so that it is half im-\\nmersed, until the leaves are about io cm. long. Then turn it so that\\nleaves are horizontal and observe where curvature occurs.\\n246. Transverse geotropism. Not all stems, however,\\nare negatively geotropic, nor all roots positively geotropic.\\nThe central axis of both root and stem in the majority of\\nplants is so, but lateral branches of both place themselves at\\nan angle to the action of gravity, sometimes at a right angle,\\nat other times at a highly obtuse or acute angle. That is,\\nthey are more or less transversely geotropic. Whatever the\\nnormal position of any organ, it will be regained by the\\ngrowing parts as rapidly as possible when the plant is forcibly\\ndisplaced. This can only be brought about by the curva-\\ntures produced by unequal growth of the younger parts.\\nIf a potted plant be laid upon its side for a short time and\\nthen erected before any response to the stimulus occurs its\\ngrowing parts still curve to one side, although not so far as if\\nthey had been allowed to remain in the horizontal position.\\n247. Grasses. In only a few cases do the maturer parts\\nof plants regain their power of growth under the stimulus of\\nFig. i2g. Part of a wheat-stalk, showing strong geotropic curvature. The shoot was\\nplaced horizontal, and the growth of the basal part of the internode with the leaf-sheath\\nconnected with it was stimulated on the under side, the upper remaining short. No\\ncurvature occurs in the older part of the internode. About two thirds natural size.\\n\u00e2\u0080\u0094After Pfeffer.\\ngravity. The basal portion of the internodes of grasses,\\nhow r ever, remain for a long time capable of growth hence,\\nwhen grasses are blown down or trampled their stems erect\\nthemselves by the geotropism of this basal growing zone\\nand of the leaf-sheath (fig. 129).", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0181.jp2"}, "182": {"fulltext": "176\\nOUTLINES OF PLANT LIFE.\\nEXERCISE XLII.\\nTo show the effect of gravity on the growing regions of the stems of\\ngrasses.\\nCover the bottom of a deep dish about 25 cm. long with a layer of wet\\nsand, and bank this against one end to the top. Into this bank stick\\nhorizontally several grass stems having at least one node cover with a\\nglass plate. After 24-48 hours observe curvature. Cut a longitudinal\\nsection of the node and observe what part the leaf-sheath takes in this\\ncurvature.\\n248. oot-cage. Experiments upon the response of root-\\nlets to the stimulus of gravity when their position is altered\\nmay be carried on by means\\nof a root-cage. It consists\\nessentially of two parallel\\npanes of glass fastened to-\\ngether, between which, in\\nfinely sifted soil, the rootlets\\nare grown. By inclining this\\nroot-cage at various angles it\\nmay be shown that not only\\nthe primary root, but its\\nbranches, strive to regain\\ntheir normal angle with the\\ndirection of gravity. This is\\nillustrated in figure 130, in\\nwhich the dark portion of the\\nrootlets represents the grow-\\ning parts while the cage was\\ninverted. They then took about the same angle with the\\nhorizon as when in normal position.\\n249. Twining plants. The movements of twining plants\\nare due to a peculiar reaction to gravity. As the upper inter-\\nnodes of a seedling elongate they soon become too weak to\\nsupport themselves and bend over, becoming nearly horizon-\\ntal. When this occurs the growth of the right or left flank of\\nFig. 130. Part of the root system of a broad\\nbean, grown in a root-cage, first in the\\nnormal, then in the inverted, and again\\nin the normal position. The arrows show\\nthe direction in which gravity acted in\\nthe different positions. The black por-\\ntion of the roots were the parts growing\\nduring inversion. Two thirds natural\\nsize.\u00e2\u0080\u0094 After Sachs.", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0182.jp2"}, "183": {"fulltext": "THE MOVEMENTS OF PLANTS.\\n177\\nthe stem near the bend is accelerated (whence the stem is said\\nto be laterally geotropic). The horizontal part is thus swung\\naround, twisting the stem and bringing a new flank under the\\ninfluence of the stimulus. If in its continued rotation the stem\\ncomes in contact with a nearly erect support the free part con-\\ntinues to rotate, growing longer at the same time, and encircles\\nthe support. The part below the\\npoint of contact now becomes nega-\\ntively geotropic, and its growth on\\nall sides is equally accelerated. The\\ncoils are thereby straightened until\\nthe stem clasps the support very\\nclosely, from which it is often pre-\\nvented from slipping by angles or\\noutgrowths of various kinds, which\\nroughen the surface (fig. 131).\\nWhile gravity thus plays a large\\npart in determining the position\\nof both aerial and subterranean FlG _\\norgans, it must be remembered\\n131. A, a bit of the stem of\\nthe hop, showing the six angles,\\neach carrying a row of emergences,\\nthat it works conjointly with many ^pS.^MaS\\nother stimuli. The position of the ^/\u00e2\u0096\u00a0^SSSSto\\nmembers is, therefore, a resultant Kerner\\nof the reactions to the various external forces which stimu-\\nlate them.\\n250. (d) Hydrotropism. Hydrotropism is the state of a\\nplant or an organ when it is irritable to moisture. Hydro-\\ntropic organs may bend toward or away from a moist surface.\\nRoots are particularly sensitive to the presence of moisture.\\nIf a cylinder of wire gauze be filled with damp sawdust and a\\nnumber of seeds planted near its surface they germinate and\\nthe roots start to grow in the normal direction i.e., directly\\ndownward. If now the cylinder be suspended at an angle,\\nas shown in figure 132, the roots which pass into the air,", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0183.jp2"}, "184": {"fulltext": "178 OUTLINES OF PLANT LIFE.\\nstimulated by the moisture, curve toward the damp sawdust.\\nUpon entering it the stimulus ceases, and they start again to\\ngrow downward, being positively geotropic. Again the\\nstimulus of the moist surface overcomes that of gravity, and\\nthey turn back to it, often threading themselves in and out\\nof the wire gauze. Since only one-sided action of a stimulus\\nFig. 132 Apparatus for demonstrating hydrotropism, a, a, a zinc disk, with hooks\\nto which is attached a cylinder or trough of wire netting filled with damp sawdust. In\\nthis are planted peas, g, whose roots, h,i, k, m, first descend into the air but soon turn\\ntoward the damp sawdust again, m has threaded itself in and out of the netting.\\nAfter Sachs.\\ndetermines direction of movement, if the air be saturated they\\ncontinue to react to the stimulus of gravity alone.\\n251. (e) Movements due to contact. Contact, either\\ngentle or forcible, and friction act as stimuli to modify the\\ngrowth of many plant parts. Only rarely is the main axis of\\na plant sensitive to mechanical stimuli, except, perhaps, to\\nlong continued contact (or pressure) in the case of some\\ntwining plants. But in many plants tendrils and leaf-stalks\\nare irritable to contact, even to a degree far surpassing that\\nof our nerves of touch.\\nIf the tip of a tendril (T 225), while still capable of growth,", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0184.jp2"}, "185": {"fulltext": "THE MOVEMENTS OF PLANTS. 1 79\\ncome in contact with a solid body, it will quickly become\\nconcave on the side touched, and thus will wrap about the\\nobject, if it be of suitable size. This curvature is due first to\\nthe shortening of the cells upon the concave side and later to\\nunequal growth on the convex and concave sides. Finally\\nthis effect extends to all parts of the tendril, which begins to\\ncurve. As both ends are fast, it is a mechanical necessity\\nthat the curves become spiral coils, both right- and left-\\nhanded, accompanied by a twisting of the tendril on its axis\\n(fig. 69). After the coils are formed the tissues of the\\ntendril become thick-walled and rigid, so that the plant is\\nattached to the support by a spiral spring.\\nOther tendrils do not nutate, but are negatively helio-\\ntropic, and by contact their tips are stimulated to develop\\ndisks which apply themselves closely to the support and send\\ninto its irregularities short outgrowths from the surface cells.\\nSuch plants are adapted to support themselves by walls, tree-\\ntrunks, etc. The Japanese ivy and one form of the Virginia\\ncreeper are notable examples.\\nThe coiling of the leaf-stalks is not unlike the first curva-\\ntures described for tendrils (fig. 100).\\nEXERCISE XLIII.\\nTo show effect of contact as a stimulus to tendrils.\\nStroke with a pencil the concave side of the tip of a tendril of passion\\nvine, squash, wild cucumber, or balsam-apple, on a warm day or in a\\nhothouse, and observe curvature which follows in a few minutes.\\n252. (B) Movements of turgor. The movements already\\ndescribed are confined to members which are growing, either\\nthroughout, or in some part. As turgor can affect only tissues\\nwhose cell-walls are elastic (^f 156), the movements pro-\\nduced directly by variation in turgor can occur only in such\\nmature members as are provided with special motor organs.\\nIn almost all cases these are leaves. Stimuli which regulate", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0185.jp2"}, "186": {"fulltext": "1 80\\nOUTLINES OF PLANT LITE.\\ngrowth (If 242) may also affect motor organs, producing like\\ncurvatures. But elongation of any part of a motor organ by\\nincreased turgor is reversible,\\nnot permanent (cf. T 213) it\\nis therefore not growth.\\n253. Motor organs. The\\nmotor organ in leaves is usually\\nthe leaf base 124) or a modi-\\nfled portion of the stalk, some-\\ntimes greater but generally less\\nin diameter than the rest. Its\\nFig 133. -Transverse sections through petiole of scarlet runner. A, through the rigid\\nportion B, through the motor organ. G, g, vascular strands c, cortex pith\\nr, deep channel along ventral side of petiole. Magnified about 10 diam. After Sachs.\\nFig. 134. -Portion of a scarlet runner, which, originally growing erect, has been inverted\\nfor several hours, resulting in geotropic curvatures of the primary motor organs P, P 1\\nP 2 The lowest pair of leaves show secondary motor organs at the juncture of petiole\\nand blade. Similar ones are present in the upper compound leaves, but are not clearly\\nshown in the figure. The arrows show the position of the petioles when the plant was\\nfirst inverted. About two thirds natural size.\u00e2\u0080\u0094 After Sachs.\\ncortex consists of large cells, and the stele occupies a rela-\\ntively small part of the transverse section. In other parts of\\nthe petiole the stele is much larger, or there may be several", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0186.jp2"}, "187": {"fulltext": "THE MOVEMENTS OF PLANTS. l8l\\nsteles distributed about the center. (See ^f 136.) In figure\\n133, A and B show the contrast. If the leaf be a compound\\none, there are usually secondary motor organs at the base of\\nthe leaflets, as in the leaf of the bean (fig. 134). Variation\\nin the turgor of the cells of the cortex upon one side or the\\nother produces a sharp curvature of the motor organ, which\\nalters the position of the leaf or leaflet (fig. 134). The con-\\ncave surface of the motor organ becomes deeply wrinkled\\ntransversely, while the convex surface is smooth.\\n254. Spontaneous movements. Only a few plants exhibit\\nspontaneous movements by means of motor organs. The\\nlateral leaflets of the telegraph plant (s,\\nfig. 135), under normal conditions of\\nrather high temperature (about 32 C),\\nshow jerky movements of such direction\\nthat their tips describe an irregular el-\\nlipse, which is completed in 1 to 3\\nminutes. The leaflets of the clovers and\\noxal is show much slower movements\\ndescribed in the next paragraph.\\nMore commonly the turgor movements Fl( f-. 135-\u00e2\u0080\u0094 Leaf of nesmo-\\nJ amm gyraiis. 1 w o\\nare induced. The most common stimuli thirds natural size.-After\\nSachs.\\nare light and contact, although many\\nothers suffice to induce them.\\n255. Light movements. Movements produced by the\\nvariations of light have long been known as sleep move-\\nments. They are best observed upon the leaves of the\\nbean family, though many other plants exhibit them. Figure\\n136 shows the positions assumed by various leaves toward\\nnightfall. It will be seen that in compound leaves the leaf-\\nlets sometimes rise, so as to apply their outer faces to each\\nother others sink, so that the under surfaces are in contact;\\nothers become folded in various ways. This position is main-\\ntained throughout the night. Upon the increase of light in", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0187.jp2"}, "188": {"fulltext": "182\\nOUTLINES OF PLANT LLFE.\\nthe morning, the day position is assumed. The cutting off\\nof light artificially from any of these plants causes them\\nFig. 136. -Photeolic movements, a, leaf of a mimosa in day position a the same in\\nnight position. leaf of Corotiilia varia in day position b the same in night po-\\nsition, c, leaf of A\u00c2\u00bbiorpka fruticosa in day position c the same in night position.\\nd, leaf of Tetragonolobus in day position d same in night position.\u00e2\u0080\u0094 After Kerner.\\nwithin a short time to assume the nocturnal position. Their\\npurpose is not certainly known.\\nEXERCISE XLIV.\\nTo show effect of intensity of light as a stimulus on certain leaves.\\nObserve the position of the leaflets of white, red, or sweet clover, bean,\\nlocust, or oxalis at 3 p.m., 6 p.m., at dusk (or after nightfall by using a\\nlantern) and at 8 A.M. In the morning darken with a box a plant show-\\ning these movements. After an hour or two, observe the position of leaf-\\nlets.\\n256. Contact movements. Some organs are sensitive to\\ncontact, as the leaves of Venus fly-trap, and other related", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0188.jp2"}, "189": {"fulltext": "THE MOVEMENTS OF PLANTS.\\n183\\nplants. The motor organ in the Venus fly-trap (figs. 224,\\n137) is the cushion of tissue running along the back of the\\nleaf between the two lobes. By the sudden variation in\\nturgor of some of these cells the two halves of the leaf are\\nthrown quickly together when one of the six bristles upon its\\nFig. 138. Fig. 139.\\nFig. 137. Part of a transverse section of a leaf of Venus fly-trap, w, the cushion of\\ntissue constituting the motor organ b, one of the sensitive bristles which, upon being\\ntouched, cause the leaf to close t, one of the interlocking teeth. The minute pro-\\njections over inner (ventral) surface are glands which secrete the digestive fluid and\\nlater absorb the food. Magnified about 5 diam.\u00e2\u0080\u0094 After Kurz.\\nFig. 138.\u00e2\u0080\u0094 A leaf of the sensitive plant fully expanded. Natural size.\u00e2\u0080\u0094 After Duchartre.\\nFig. 139. A leaf of the sensitive plant after stimulation The motor organ at the base\\nof each leaflet has thrown it forward and upward the motor organs at the base of\\nthe four divisions have moved them together. The motor organ at the base of the\\nmain petiole has moved the whole leaf sharply downward. Natural size. -After\\nDuchartre.\\nupper surface is touched. The sensitive plant drops one of\\nits leaflets or the whole leaf quickly when stimulated by con-\\ntact, heat, or electricity. The position of the leaves when\\nnormally expanded is shown in figure 138, and their position\\nafter stimulation by figure 139. The stamens (^j 287) of\\nsome flowers and the stigmas 283) of others are sensitive", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0189.jp2"}, "190": {"fulltext": "1 84 OUTLINES OF PLANT LIFE.\\nto a touch, shortening, elongating, or bending in such a way\\nas to promote pollination ^f 295).\\nThe motor organs of the leaves of a number of the bean and\\noxalis families also react to more violent mechanical stimuli.\\nTheir movements are similar to those described in ^f 255.\\n257. Summary. By irritability, that is, the sensitiveness\\nof protoplasm to external agents, plants are able to regulate all\\ntheir activity and adjust themselves to the world about them.\\nUnder unfavorable conditions this sensitiveness is temporarily\\nlost. If permanently lost, it is death. It is more marked in\\nsome parts than others and its effects in these parts are capable\\nof being transmitted to distant parts.\\nThe reactions of plants to stimuli are most easily observed\\nwhen they result in movements. Movements of the proto-\\nplasm itself seem to be automatic, but can be directed by ex-\\nternal stimuli. Movements of multicellular plants are due\\neither to unequal growth or to unequal turgor. Light,\\nheat, gravity, moisture, or contact may so influence the rate\\nof growth, or the amount of turgor as to cause curvature of\\ngrowing parts or of a special motor organ. The parts affected\\nmay thus be turned toward or away from the source of the\\nstimulus, or may be placed transverse to it. Movements in\\nresponse to gravity, light, and heat are most important.\\nThese work conjointly to determine the position of organs.", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0190.jp2"}, "191": {"fulltext": "PART III: REPRODUCTION.\\nCHAPTER XVII.\\nVEGETATIVE REPRODUCTION.\\n258. Introduction. Having considered in Parts I and II\\nthe structures and functions by which the nutrition of the\\nindividual is secured, Part III is devoted to the consideration\\nof the structure and functions of some of the simpler repro-\\nductive organs and the functions by which a succession of\\nsimilar individuals is insured. (For fuller discussion see\\nPlant Life.)\\nOne of the fundamental powers of protoplasm is its ability\\nto produce new organisms as offspring from the older ones.\\nIn the simpler plants the two great functions, nutrition and\\nreproduction, are often carried on by the same cell. This\\nmust always be so in the unicellular plants. In the higher\\nplants, however, these two functions become completely\\nseparated, organs being specialized for each, so that the\\nfunctions may be more certainly and efficiently performed.\\nAny part capable of growing into a new individual may be\\ncalled a reproductive body, and the part on which or in which\\nit is produced is a reproductive organ. If the reproductive\\nbodies consist of one or two cells only, they are usually\\ncalled spores. If they are cell-masses, they are generally\\ncalled brood buds or gemmce to distinguish them from ordi-\\n185", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0191.jp2"}, "192": {"fulltext": "1 86 OUTLINES OF PLANT LIFE.\\nnary buds. In both cases it is necessary that the cells to be\\nseparated from the parent should be capable of growth that\\nis, in the condition known as the embryonic phase (^f 215).\\nThe reproductive organs produced by some plants are ex-\\nceedingly complex and varied, while others form reproduc-\\ntive bodies in very direct ways. The reproductive bodies\\nthemselves are generally very simple. In addition to com-\\nplex reproductive organs, there are sometimes accessory parts\\nby which the plant adapts its reproductive functions to the\\nconditions under which it lives. Among these accessory\\nstructures are many, as among the flowers of seed plants, by\\nwhich the aid of other plants or animals is secured.\\n259. Vegetative and sexual reproduction. In all the\\ndiversity of organs and processes two chief methods may be\\ndistinguished, called vegetative reproduction and sexual repro-\\nduction.\\nVegetative reproduction consists in the formation of repro-\\nductive bodies by processes of growth only. The modes in\\nwhich they arise are varied in detail, but consist essentially\\nin the production by the parent of a body, unicellular or\\nmulticellular, which at maturity develops, under suitable\\nconditions, into a new plant. It is scarcely to be doubted\\nthat the earliest methods of reproduction were vegetative, and\\nthat sexuality has been acquired by a gradual adaptation of\\ncells previously devoted wholly to ordinary processes of\\ngrowth.\\nSexual reproduction consists in the formation of reproduc-\\ntive bodies by the union of two specialized cells, neither of\\nwhich alone is capable of developing into a new plant.\\nI. Fission and budding.\\n260. Fission. In single-celled plants cell division and\\nreproduction are practically identical, since shortly after\\ndivision occurs the two cells so produced separate and lead", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0192.jp2"}, "193": {"fulltext": "VEGETATIVE REPRODUCTION. 1 87\\nan independent existence (C, fig. 10). Such a method of\\nreproduction evidently interferes Little with the processes of\\nnutrition, which probably are scarcely even suspended during\\nthe process of reproduction.\\n261. Budding. A slight variation of the method of fission\\njust described is to be found in those single-celled plants,\\nsuch as the yeasts, whose growth is so localized as to form\\nupon one side a small enlargement which ultimately attains\\nthe size of the parent, with which it is connected by a very\\nnarrow neck (fig. 29). Across this neck the partition wall\\nis formed in the usual way. This becomes mucilaginous,\\nrendering the adhesion of the daughter cell at this point so\\nweak that it is easily separated from the parent. This\\nmethod of reproduction is known as budding.\\n262. Fragmentation. In those plants which consist of\\na row of cells more or less closely united, the breaking up of\\nthe filaments into separate pieces, either through external\\nforce or the death of one of the cells, may produce a number\\nof smaller colonies or of new individuals, each of which may\\ngrow to full size. In some of the more loosely organized\\nfilament-colonies, such as Nostoc (see 11, and fig. 6),\\nthere are specialized cells whose function seems to be to\\nloosen pieces of definite length, which creep out of the jelly,\\ngrow, and thus produce new colonies.\\nThe greater size reached by most multicellular plants soon\\nrenders impossible the continuance of this method of repro-\\nduction, except among those whose cells are all alike.\\nShould such separation into nearly equal parts occur among\\nmore highly specialized plants, it is evident that one portion\\nmight easily be left without nutritive organs adapted to its\\nneeds. The higher plants, therefore, specialize certain\\nregions or members, where, by division or budding or similar\\nprocesses, reproductive bodies may be formed.", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0193.jp2"}, "194": {"fulltext": "188\\nOUTLINES OF PLANT LIFE.\\nII. Spores.\\n263. Sexual and non-sexual spores. A spore is a single-\\ns celled body capable of producing\\na new plant. Spores may be\\nformed either by a process of\\ngrowth or by the union of two\\ncells. The former are called non-\\nsexual spores; the latter, sexual\\nspores. Only non-sexual spores\\nare discussed in this chapter.\\n264. Motile spores. Spores\\nmay be either naked and motile\\nor furnished with a cell-membrane\\nand non-motile. The former are\\ncommonly produced by plants\\nwhich pass all or part of their lives\\nin water, such as the algae and\\naquatic fungi. They are usually\\npear-shaped and furnished with one\\nor more cilia, by means of which\\nthey swim about (figs. 109, 140).\\nWhen locomotion was supposed\\nto be a distinctive power of ani-\\nmal bodies they were called zoo-\\nspores, a name still retained. They\\nare also called swarm-spores.\\nZoospores are formed either in\\na general body-cell, not visibly\\nFig. 140. Development and escape\\nof zoospores of an aquatic fungus\\n{Saprotegnia lactea). The ends\\nof two hyphae are shown, the ter-\\nminal cells being spore cases. In\\na, the protoplasm is gathering to different\\nform spores. From b many of\\nfrom\\nin a\\nspores\\nthe zoospores have escaped polio or\\nthrough the perforation in the tlia\\nwall near the upper end of the f m anc J structure, the SDOre Case\\nI. From c all have escaped r\\nthe other body-\\ncell specialized in\\ncell.\\nbut one which is just slipping Th entire contents of the spore\\nthrough the opening (here in pro- x\\nKeraer Magnified30odiam _After case ma form a single zoospore,\\nor it mav divide into several or many.\\nThe zoospores are", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0194.jp2"}, "195": {"fulltext": "V EG ETA TIVE REP ROD UCT10N.\\n189\\nset free by the rupture or by the solution of a portion of the\\nenclosing wall (lig. 140). They may begin to move before\\nthe rupture of the wall, in accomplishing which their activity\\nmay materially assist. They then work their way out and\\nswim freely in the water. After a time of movement they\\nusually lose their cilia, either withdrawing them into the\\nprotoplasm or dropping them off, come to rest, and begin to\\ngrow into a new plant.\\n265. Non-motile spores are formed by all classes of land\\nplants without exception. They are often produced in great\\nprofusion, especially by the fungi, the mosses, the ferns, and\\nthe seed plants.\\n266. Form and food. Their form is exceedingly various.\\nMany are spherical or ovoid, while some are cylindrical or\\nco\\nFig. 141.\u00e2\u0080\u0094 Part of a vertical section of a leaf of a willow, attacked by a fungus (Melamp-\\nsora salicina). eo. epidermis of upper side lifted by the young teleuto-spores, t, de-\\nveloping from the spore-bed above the ends of the palisade cells of the host (par)\\neu, epidermis of the under side, broken through by the spore-bed from which spring\\nuredo-spores, st, and paraphyses, p. eo will also finally be ruptured to- set free t.\\nMagnified 260 diam. After Prantl.\\neven needle-shaped (figs. 141, 143, 166). Irregular forms,\\nalso, are not uncommon. The same plant may produce at", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0195.jp2"}, "196": {"fulltext": "190 OUTLINES OF PLANT LIFE.\\ndifferent stages or in different parts spores which are unlike\\nin form and nature (compare and st, fig. 141). In almost\\nall cases there is a supply of reserve food within the spore,\\nwhich varies in amount with the conditions under which they\\nare formed. It is ordinarily greater in resting spores than in\\nthose intended for immediate growth.\\n267. Growth. Spores germinate by absorbing water,\\nthus bursting the more rigid outer layer or layers of the cell-\\nwall. The inner layer then grows in area to accommodate\\nthe increasing protoplasm, which so controls the mode of\\ngrowth as to produce a plant of definite form. In many\\ncases the plant produced is essentially like that which gave\\nrise to the spore. In others it is different, but sooner or\\nlater in the life cycle the same form recurs.\\n268. Origin. Non-motile spores are either free, being\\nproduced at the ends of branches specialized for that pur-\\npose, or enclosed in a spore case. Often the same plant\\nforms spores by both methods at different stages in its\\ndevelopment.\\n269. Free spores. The formation of free spores is con-\\nfined to the lower plants, and is especially characteristic of\\nthe non-aquatic fungi. The branches producing spores may\\noccur singly, or, more commonly, they are grouped at\\ncertain points, forming a spore-bed (fig. 141). If the fungus\\ndevelops its mycelium in the interior of a host, the formation\\nof a spore-bed is often necessary to rupture the host, so that\\nthe spores may be brought to the surface and set free. Thus\\nthe spore-beds of parasitic fungi commonly blister the surface\\nof the host by lifting up its outer tissues (eo, fig. 141).\\nSpores may be produced either singly at the ends of the\\nbranches, or in chains (fig. 142).\\nA modification of the production of spores singly occurs\\nwhen the branch destined to produce them gives rise to two\\nto eight very slender branches, each of which enlarges at the", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0196.jp2"}, "197": {"fulltext": "V EG ETA TIVE RE PROD UCTION.\\nI 9 I\\ntip into a single spore, so that the main branch appears to\\ncarry two to eight spores upon slender stalks (fig. 143).\\nFig.\\nFig.\\n142. biG. 143-\\nFig. 142.\u00e2\u0080\u0094 An outline showing the formation of a spore-chain of the biue-green mold\\n{Penicillium glaucuni). b, branch of spore-bearing hypha, budding beneath two\\nolder spores. Across the narrow neck a partition wall is formed, the spores round off,\\nand from this wall a device, c, for loosening the spores is developed. The terminal\\nspore is oldest. Highly magnified.\u00e2\u0080\u0094 After Frank.\\nFig. 143.\u00e2\u0080\u0094 Longitudinal section through the edge of a gill of a mushroom {Coprinus)\\nafter spore-formation is completed. interwoven hyphae of the gill, branching to\\nform the spore bed, composed of sterile branches, swollen branches, c, and spore-\\nbearing branches, b. The latter give rise to four slender branches, whose tips enlarge\\nto form each a single spore. and c do not produce spores. Magnified 300 diam.\\nAfter Brefeld.\\n270. Fructifications. In the higher fungi whose my-\\ncelium is developed within a dead substratum many hyphae\\nare aggregated to constitute a reproductive structure or fruc-\\ntification, which is the only conspicuous part of theiungus.\\n(For an account of the vegetative parts, see 43, 47).\\nThe body of the fructification is made up of hyphae, more\\nor less interlaced and adherent, and is of a form adapted\\nnot only to break through the substratum, but also to\\nfurnish an extensive surface for the spore-beds (fig. 143).\\nThe fructification may be irregularly lobed, sessile and\\ngelatinous, or much branched and cylindrical or flattened;\\nthe shapes being adapted in various ways to form an exten-\\nsive surface on which spores may be formed (figs. 144, 145).", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0197.jp2"}, "198": {"fulltext": "192\\nOUTLINES OF PLANT LIFE.\\n271. Simple spore cases. Spores are also formed loose\\nin the interior of cells. Each spore-containing cell is\\nFig. 144.\\nFig. 144.\u00e2\u0080\u0094 A fructification of Clavaria\\naurea. The spore beds cover the upper\\npart of the branches. Natural size.\u00e2\u0080\u0094 v n _._,\\nAfter Kerner. r 1G I45\\nFig. 145. A fructification of a mushroom, Amanita f halloides. p, the cap or pileus;\\n7; the veil, originally connected with edge of cap, covering the gills which radiate\\nfrom the stipe, st, to the edge of cap vo, the volva. The surface of the gills is\\ncovered with the spore beds. Most mushrooms showing a distinct volva are poison-\\nous. Natural size.\u00e2\u0080\u0094 After Kerner.\\ncalled a simple spore case (fig. 146). In the lower plants,\\nthe spore case may be merely one of the general body-cells,\\nor it may be specialized in form as well as in function. It\\nmay be spherical, sac-like, or linear. The number of spores\\nformed within a simple spore case may be two or more, up\\nto several hundred. Simple spore cases may be formed\\nsingly or they may be grouped.\\n272. Compound spore cases. In the higher plants, in-", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0198.jp2"}, "199": {"fulltext": "VEGE TA TI VE REPR ODUC TION.\\n193\\neluding the mossworts, fernworts, and seed plants, the spore\\ncase is always formed of two or more spore-producing cells,\\nsurrounded by a covering of cells (one or more layers) which\\ndo not produce spores. These spore cases may be developed\\nFig. 146. Pig. 147.\\nFig. 146. Longitudinal section of the simple spore case of a mold (Mucor). The aerial\\nhypha, h, has partitioned off a cell, s, within which spores are produced. The walls\\nof this spore case are studded with needle crystals of calcium oxalate. The partition\\nprotrudes far into the spore case. Magnified 260 diam. After Kerner.\\nFig. i 47. Longitudinal section of the stem, s, of a moss gametophyte, bearing leaves,\\nb. Embedded in the stem is the sporophyte, consisting of a stalk, si, and a compound\\nspore case, of which iu is the wall, formed of a sheet of cells, enclosing the spores,\\ns/ (contents not shown). Magnified 100 diam. After Hofmeister.\\neither from superficial or from internal cells. As a conse-\\nquence, the mature sporangia will be either free or more or\\nLess enclosed within the tissues of the organ by which they\\nare borne.\\n273. The sporophyte. Among the mossworts, fernworts,\\nand seed plants reproduction by spores has become so fixed\\nand important that one stage in the plant is devoted espe-\\ncially to producing them. This phase is different from that\\nproducing sex cells, the difference becoming greater the more\\ncomplex the plant. The stage set apart for spore production\\nis called the sporophyte. In the mossworts the sporophyte\\nhas very little green tissue, and therefore carries on little\\nnutritive work, but depends for its supply of food chiefly", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0199.jp2"}, "200": {"fulltext": "I 9 4\\nOUTLINES OE PLANT LIFE,\\nspin\\nupon the sexual stage, with which it is connected throughout\\nits entire existence (^f 60). In\\nthe fernworts and seed plants,\\nhowever, the sporophyte pos-\\nsesses extensive nutritive tissues,\\nthe leaves, stems, and roots be-\\nlonging entirely to this stage.\\nSporangia in these plants may\\nbe formed either upon the stem\\nor the leaves never upon the\\nroots.\\n274. Liverworts and mosses.\\nIn most liverworts and mosses\\nthe spore case is developed within\\nthe enlarged upper part of the\\nsporophyte, to which the name\\ncapsule is given (figs. 46, 148,\\nand 59). By the time the\\nspores are mature the capsule\\nhas become filled with the loose\\nspores. It bursts at the top or\\nopens by the falling off of the\\nlid-like upper end, and thus\\nFig. 148.\u00e2\u0080\u0094 Longitudinal section of the A x\\nyoungcapsuleofatruemoss(\u00c2\u00a3rj/\u00c2\u00abw). allows the SDOreS to escape.\\nj, spore case. At this stage the mother r\\ncells of the spores, spm, have become 275. FemS. 111 the ferns the\\nfree (only a few are shown, still en-\\nclosing the spores, which are later re- sporophyte phase is the plant\\nleased i sw, the wall of the spore r r J\\ncase, lined by the remains of another with TOOtS and leaves. The\\nlayer of cells now disorganized c, the\\ncolumella, of partly collapsed ceils spore cases are either produced\\nfs, intercellular space cw, wall of r\\nthe capsule; an, the annulus, a ring upon the Under Surface of the\\nof cells which pries off the lid, at r\\nwhose edge they develop; ot, the foliage leaves or upon specialized\\nouter, 7 i, the inner peristome, formed\\nby the thickening of parts of the wails leaves. Thev are usuallv numer-\\nof certain rows of cells nt, nutritive J\\ntissue, with chioropiasts and intercei- ous stalked, free, and often as-\\nlular spaces. Magnified 25 diam.\\nOriginal. sociated in clusters. The clus-\\nters are often arranged in elongated groups or lines (fig. 149)-", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0200.jp2"}, "201": {"fulltext": "VEGE TA Tl VE RETROD UCTION.\\n195\\nEach cluster may be protected by a special outgrowth from\\nthe cells in its neighborhood (figs. 149, 150)\\ncase consists of a stalk expanding above\\ninto a body composed of a single outer layer,\\nenclosing at maturity the loose spores (fig.\\n236).\\n276. Spore leaves. In many of the ferns\\nthe leaves which produce spore cases are\\nnot different from the foliage leaves. In\\nothers, certain leaves are so specialized for\\nbearing the spore cases that they abandon\\ntheir nutritive work in part or entirely. To\\nsuch specialized leaves the name spore\\nleaves is applied.\\nEach spore\\nFig. r4g.\u00e2\u0080\u0094 A leaflet of\\na fern {Aspiditim\\nseen from the back.\\nEight clusters of\\nspore cases are\\nshown, each cov-\\nered by its own in-\\ndusium, i. Mag-\\nnified 2 diam.\\nAfter Sachs.\\n276a. Differentiation of sp res Among higher\\nfern worts the spores are of two sizes: large ones,\\nknown as megaspores, and much smaller ones known\\nas microspores (fig. 151). Each kind, when it germinates, produces a\\nsexual plant. The megaspores give rise to plants bearing female organs\\nonly, the microspores to those bearing male organs only. A similar\\nseparation of sexes in the gametophytes frequently occurs when the spores\\nFig. 150.\u00e2\u0080\u0094 Vertical section through the leaflet shown in fig. 149, passing through the\\ncenter of a spore-case cluster, e, ventral epidermis; e dorsal epidermis; between\\nthem the mesophyll, showing 3 veins cut across over the central one is a cushion of\\ntissue from whose surface arise the stalked spore cases s, s. i, 2, the indusium. Mag-\\nnified about 30 diam.\u00e2\u0080\u0094 After Sachs.\\nare equal in size, as in Marchantia and horsetails, but it always occurs\\nwhen they are unequal. A corresponding difference in size is often found", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0201.jp2"}, "202": {"fulltext": "196\\nOUTLINES OF PLANT LIFE.\\nbetween the spore cases containing small spores and those containing large\\nspores (fig. 151).\\nIn the seed plants this difference in the spores is always found. The\\nmicrospores are called J o//engrains\\nand the megaspores after germination\\nare called embryo-sacs The spore\\ncases also are always different in form\\nand structure, and the leaves upon\\nwhich they are usually borne are also\\nof two distinct forms. In no case do\\nspore leaves perform nutritive work;\\nthey are always specialized. Those\\nleaves which bear pollen grains are\\ncalled stamens, and the leaves which\\nFig. 151.\u00e2\u0080\u0094 Section through three spore produce the megaspores are called\\ncase clusters of an aquatic fernwort\\n(Salvinia nataiis). Each is cov-\\nered by a double indusium. i, 2,\\ntwo clusters consisting of small spore\\ncases, each containing 64 micro-\\nspores; a, a cluster consisting of\\nlarge spore cases, each containing\\none megaspore. Magnified 10 diam.\\nAfter Sachs.\\ncarpels* (figs. 156, 157). In spite of\\nthese special names, it must be care-\\nfully borne in mind that the spore cases\\nand spore leaves of the seed plants are\\nnot different from those of the fern worts\\nor mossworts in anyessentialparticular.\\n277. The spore leaves of the seed plants are usually\\nclustered by the failure of the internodes of the axis to\\nlengthen as much as between the foliage leaves. Very often,\\nalso, the leaves adjacent are modified in form and color to\\nadapt them to securing the dispersal of the pollen by various\\nagents, especially insects. Such a shoot bearing stamens,\\ncarpels, and accessory leaves is called a flower. As a similar\\naggregation of the spore leaves occurs in horsetails and many\\nclub-mosses it is evident that the flower is not distinctive of\\nthe seed plants, though it attains the highest specialization\\namong them.f\\nThese special names were given because the seed plants were first\\nstudied, and it was long before the real nature of the parts and their re-\\nlation to similar ones in the lower plants were known. The terms are\\nstill in use, and are likely to continue to be used for convenience.\\nf It is for this reason that the term seed plants is preferred to flowering\\nplants.", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0202.jp2"}, "203": {"fulltext": "V EG ETA TIVE REP ROD UCTIOA 7\\nI 9 7\\nFig. 152. A flower of linden, halved show-\\ning a pestle-like pistil. Magnified about\\n3 diam. After Kerner.\\nThe parts and functions of the flower of seed plants are\\nnow to be discussed.\\nThe Flower.\\n278. A flower usually consists of a shortened axis, the\\ntorus, bearing several floral leaves (figs. 66, 152). The\\nspore leaves are known as\\nessential organs, the accessory\\nleaves as the perianth and\\nbracts.\\nThe essential organs are of\\ntwo sorts, stamens and carpels.\\nIn any flower they may be all\\nstamens or all carpels, or may\\ninclude both sorts. The\\nperianth may be composed of\\none or two kinds of leaves,\\noften bright-colored. If there are two sorts, those next the\\nspore leaves are generally highly colored, and constitute the\\ncorolla. Each leaf of the corolla, when distinct, is a petal.\\nThe leaves below the corolla are often green. They con-\\nstitute the calyx, and each, when distinct, is a sepal.\\n279. Carpels. The leaves bearing the ovules are called\\ncarpels. They may be flattened; or so curved that in the\\ncourse of their development the edges unite and a cavity is\\nmore or less perfectly enclosed; or neighboring carpels may\\ngrow together in such a way as to form a case. Such hollow\\nstructures, whether composed of one or more carpels, are\\noften somewhat pestle-shaped, whence they early received\\nthe name pistil (fig. 152). A flower whose only essential\\norgans are pistils is called pistillate.\\n280. Ovules. Among seed plants the spore cases which\\nthe carpels bear are universally known as ovules, a name\\ngiven to them under the supposition that they were the eggs\\nwhich, upon fertilization, produce new plants. Though they", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0203.jp2"}, "204": {"fulltext": "I9\\nOUTLINES OF PLANT LIFE.\\nare not in any respect comparable to the real eggs (since they\\nare produced by the non-sexual or sporophyte phase), the\\nname is retained for convenience. The ovules arise usually\\nupon the ventral (inner) face or the edges of the carpels.\\nIn the open carpel they are exposed, but in the closed carpels\\nthey are completely shut in, except for a narrow opening\\nwhich sometimes remains, by which the interior cavity com-\\nmunicates with the outside air.\\n281. Gymnosperms and angiosperms. When the changes\\nthrough which the ovule passes are complete, it becomes the\\nseed. When the ovules are produced\\nupon the free surface of an open carpel,\\nthe seeds are, therefore, exposed. On\\nthe contrary, when the ovules are borne\\nwithin a closed pistil (formed by one or\\nmore carpels) the seeds are developed\\nwithin this case, by which they are pro-\\ntected until mature, or longer.\\nThese two methods of seed produc-\\ntion form the basis for the separation\\nof the seed-bearing plants into two\\ngreat groups, one known as gymno-\\nsperms, or plants with naked seeds, the\\nyoung cone-\\nFig. 153\\nscale of Scotch pine show-\\ning the two ovules the\\nlatter halved parallel to\\nthe scale, showing the\\nbody of ovule and the pro-\\n!hfS e en 0n Tt! other as the angiosperms, or plants\\nscale is attached at b.\\nMagnified about 8 diam.\\nAfter Kerner.\\nwith encased seeds. Open carpels (fig.\\n153) are found exclusively among the\\ngymnosperms, to which belong the cone-bearing, mostly\\nevergreen, trees, while the closed pistils are chiefly found\\namong angiosperms, to which belong the majority of garden\\nand field plants and the deciduous forest trees.\\n282. The closed pistils of angiosperms are usually distin-\\nguishable into (1) an enlarged basal part, the ovulary*\\nThis part was early called the ovary (a name which is still in general\\nuse), meaning the organ which produces eggs, under the impression that", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0204.jp2"}, "205": {"fulltext": "VEGE TA T1VE RETROD UCTION.\\nI 99\\ncontaining the ovules, surmounted by (2) a slender part of\\nvariable length, the style, which is terminated by (3) a rough,\\nsticky, or branched part, the stigma. (See figs. 152, 156.)\\n283. Stigma and style. The stigma may take the form\\nof a knob, a ridge, a straight or wavy line, or be lobed or\\nbranched. However compact, it is usually roughened by\\nthe prolongation of its surface cells into rounded, pointed, or\\nhair-like extensions (fig. 154), which frequently secrete a\\nsticky fluid. Its purpose is to secure\\nthe adhesion of the pollen spores\\nbrought to it by various agents, among\\nthe most important of which are the\\nwind and insects.\\nThe style may be thick or slender,\\nlong or short, branched or unbranched,\\nhollow or solid. It is frequently\\nwanting.\\n284. Simple and compound pistils.\\nWhen several carpels are present in\\none flower they may form as many\\nseparate simple pistils as there are\\ncarpels. If numerous, the axis will\\nbe enlarged or elongated to accom-\\nmodate them. (See 296, and fig.\\n173.) Instead of forming separate\\npistils, the carpels may be united to form a single compound\\npistil.\\nThe union of the carpels may be only at the base; or it\\nFig. 154.\u00e2\u0080\u0094 One of the hairs\\nfrom the stigma of corn\\ncockle {Lychnis git h ago)\\nto which a pollen grain ad-\\nheres. The pollen tube has\\npenetrated the hair and is\\nmaking its way down the\\nstyle. Magnified 175 diam.\\nAfter Strasburger.\\nthe ovules little eggs) were like the eggs of birds, an idea which was\\nfurther carried out in the name albumen given to the food stored in the\\nseed. (See 305.) To avoid confusion with the true ovary in which\\nthe real egg is produced, I use the name ovulary i.e., the organ which\\nproduces ovules. The word ovule, though as bad in etymology as\\novary, is convenient, and does not lead to any confusion.", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0205.jp2"}, "206": {"fulltext": "200\\nOUTLINES OF PLANT LIFE.\\nmay involve the entire ovulary, leaving the styles free; or\\nthe union may be complete, with the exception of the\\nstigmas; or it may involve even them (figs. 155, 156).\\nFig.\\nFig.\\n[55. .TIG. 156. *IG. 157.\\nFig. 155. Pistil of white hellebore {Veratrum album) showing three carpels separate\\nabove only. Magnified about 6 chain.\u00e2\u0080\u0094 After Berg and Schmidt.\\nFig. 156.\u00e2\u0080\u0094 Calyx and pistil of the manna ash (Fraxinus or mis) showing calyx leaves\\nunited at base and carpels united throughout, the slightly 2-lobed stigma only giving\\nexternal evidence of their number. Magnified several diam. \u00e2\u0080\u0094After Berg and Schmidt.\\nFig 157. Pistil of white potato halved transversely, showing two carpels united at\\ncenter where their edges form a large placenta on whose surface the ovules arise.\\nMagnified several diam.\u00e2\u0080\u0094 After Kerner.\\n285. The ovulary.\u00e2\u0080\u0094 The cavity of the ovulary is either\\nundivided or partitioned into as many chambers as there are\\ncomponent carpels (fig. 157); or the normal number of\\n-rs r\u00e2\u0080\u0094 ~i~ T^ A chambers in the ovulary may be in-\\n^S ^SIIJ^ S^y creased by outgrowths from the carpels\\nthemselves (fig. 158).\\n286. Ovules. An ovule consists of a\\ncentral body, the spore case, in which the\\nmegaspores are formed. In a few ovules\\nas many as 20 to 40 megaspores begin to\\ndevelop in most only one to four. Even\\nwhen several megaspores begin to form it\\nis rare for more than one to reach per-\\nfection; the remainder disappear almost completely. The\\nmegaspore never escapes from the spore case for this reason\\nthe megaspore looks more like a cavity in the ovule than like\\nFig. 15S. A transverse\\nsection of the capsule of\\nshepherd s purse. The\\npistil consists of two\\ncarpels, at whose united\\nedges two placentas are\\nformed carrying the\\novules (now seeds). The\\npartition from one pla-\\ncenta to the other is an\\noutgrowth (false parti-\\ntion) and not part of the\\ncarpel. Magnified about\\n6 diam.\u00e2\u0080\u0094 After Bessey.", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0206.jp2"}, "207": {"fulltext": "J EGE TA TIVE REP ROD UCTION.\\n20 1\\na spore. Because an embryo appears later inside this ap-\\nparent cavity, the megaspore of seed plants has long been\\ncalled the embryo-sac.\\nThe spore ease is surrounded by one or two integuments.\\nThese arise as outgrowths from the parts adjacent. If the\\nspore case is to have two coats,\\nthe inner appears first as a low\\nring around its base gradually\\ngrowing up around it; the outer\\nshortly appears in the same way\\n(fig. 159). These integuments,\\nas well as the spore case, often\\ngrow unsymmetrically, so that at\\nthe maturity of the megaspore the\\novule is often variously curved\\n(figs. 159, 160). The megaspore\\nitself may be distorted by this means so as to lose still more\\nits likeness to a spore.\\nOvules are borne either upon the axis itself or upon\\nFig. 159. Two very young ovules\\nof the California poppy (Esch-\\nscholtzia\\\\, seen from the outside.\\nB, somewhat older than A. nc,\\nthe rudiment of the spore case\\njc, rudiment of the inner integu-\\nment pr, rudiment of the outer\\nintegument fn, the stalk. Mag-\\nnified 140 diam. After Duchartre.\\nFig. 160.\u00e2\u0080\u0094 Diagrams of median longitudinal sections of three sorts of ovules to show\\ncurvatures due to unsymmetric growth. A, a straight, B, an inverted, C, a bent ovule.\\nIn all f, the stalk k, the spore case; it, the inner integument; ai, the outer in-\\ntegument m, the micropyle c, the base of the spore case where the integuments\\narise (called the chalaza) r, ihe ridge (rhaphe) formed by the union of stalk and outer\\nintegument; e n, the megaspore. As C develops further em may become sharply\\nbent on itself. After Prantl.\\nthe carpels. It is usual for the ovules to arise upon a car-\\npel, either singly or in clusters, from a cushion or ridge,", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0207.jp2"}, "208": {"fulltext": "202 OUTLINES OF PLANT LIFE.\\ncalled the placenta. The placenta in angiosperms is com-\\nmonly located at the united edges of the carpel or car-\\npels. If the carpels are united into a compound pistil, the\\nplacentas will be either isolated, as ridges upon the inner\\nface of the wall of the ovulary (fig. 158), or aggregated at its\\ncenter (fig. 157). Occasionally the ovules arise upon the\\nentire inner face of the carpels, as in the gentians.\\n287. Stamens. A stamen is a leaf of the seed plants\\nwhich bears the pollen sacs. The flowers whose essential\\norgans are all stamens are said to be staminate. Rarely a\\nsingle stamen constitutes a flower. Except for the crowd-\\ning, the stamens are arranged like all the other leaves of the\\nplant, arising on the axis alternately, or in one or more\\ncircles. The stamens exhibit great diversity of form and size.\\nEach usually consists of two parts, a stalk, called the\\nfila?nent, bearing an enlarged portion, called the anther {si,\\nfig. 66).\\nThe anther is usually larger than the filament and com-\\nmonly two-lobed, having the sporangia located in the thicker\\nparts.\\n288. Spore cases. The anther bears from 1-12 pollen\\nsacs (spore cases) upon its surface, or wholly or partly sunk\\nin its tissues. In most anthers the pollen sacs are either two or\\nfour (fig. 161). When there are four they are often paired, and\\neach pair may become confluent by the absorption of the\\npartition between them (fig. 162). This occurs about the\\nsame time that the outer wall bursts in order to set free the\\nspores. Such anthers, at the time of opening, are apparently\\ntwo-chambered.\\n289. Dehiscence. The opening of the chambers occurs\\nin one of three ways: by pores, by slits, or by valves. (1)\\nA small area of the outer wall is absorbed or breaks away so\\nthat the pollen spores sift out through the pore so formed\\n(fig. 163); or (2) a crack begins at one point and extends", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0208.jp2"}, "209": {"fulltext": "VEGETA TIVE REP ROD UCTION.\\n203\\nlengthwise of the anther (fig. 164); or (3) the break occurs\\nalong a line considerably curved, and the flap (valve) thus\\nFig. 161.\u00e2\u0080\u0094 Transverse section of the anther of thorn-apple {Datura Stramonium),\\nc, connective, with a small stele embedded in parenchyma a,/ a,/ the four spore\\ncases, arranged in pairs showing pollen grains. When the spore cases break, the\\nwalls rupture at the groove between a and/. Magnified about 25 diam.\u00e2\u0080\u0094 After Frank.\\nloosened curls up or lifts so as to allow the escape of the\\nspores (fig. 165). All three methods are dependent upon\\nsome special structure of the wall of\\nthe spore case at the lines of rupture\\n(figs. 161, 162).\\n290. Union. The stamens are\\nnot infrequently united with one an-\\nother or with some of the neighbor-\\ning leaves of the flower. They may\\nbe united to one another by their fila-\\nments only, or by their anthers only,\\nor throughout their whole length.\\nUnion with the pistil or pistils is\\nrather uncommon, but union with\\nthe corolla or calyx is very frequent.\\nThe stamens also branch just as\\nordinary leaves do.\\n291. Pollen grains. The spores produced in the spore\\ncases of the stamens are of various forms, being round,\\nFig. 162. Transverse section of\\nbursted anther of a lily (Bzito-\\nmus tunbellatus). Sporangia\\nhave ruptured at z, so that the\\ntwo pairs have each formed a\\nsingle cavity. The connective\\nis relatively small in the cen-\\nter a single stele. Magnified\\nabout 20 diam. After Sachs.", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0209.jp2"}, "210": {"fulltext": "204\\nOUTLINES OF PLANT LIFE.\\novoid, or even angular, with the surface smooth, grooved, or\\nroughened with few or many bosses, points, or ridges, as in\\nother spores (A-D, fig. 166). They are either dry and\\npowdery when the sporangia burst, or are moist and sticky,\\nFig. 163. Fig. 164. Fig. 165.\\nFig. 163. Anther and pollen of a Rhododendron. A, the anther, opening by pores at\\nthe end and allowing the pollen to escape. Magnified 8 diam. B, pollen grains ad-\\nherent in fours (tetrads) as formed in the mother cells; the tetrads are held together\\nby a sticky material which draws out into cobwebby threads as they are separated.\\nMagnified 50 diam.\u00e2\u0080\u0094 After Kerner.\\nFig. 164. Anther of the sweet violet {Viola odorata), showing the pollen sacs opening\\nby slits. Magnified about 5 diam.\u00e2\u0080\u0094 After Kerner.\\nFig. 165. A flower of cinnamon, halved. The calyx and stamens are raised on a cup\\ndeveloped around the pistil. The anthers open by uplifted valves, one for each spo-\\nrangium, which here are arranged in two stories instead of in pairs side by side. Mag-\\nnified about 7 diam. After Luerssen.\\nadhering to each other in larger or smaller clusters (fig. 163).\\nSometimes, as in orchids and milkweeds, they are all held\\ntogether in one mass and are attached to a part of the anther\\nwhich carries the mass like a stalk or handle (fig. 167). Dry\\nspores are usually adapted to distribution by wind; while the\\ncoherent spores are adapted to carriage by small animals,\\nespecially insects. (See further 295.)", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0210.jp2"}, "211": {"fulltext": "VEGE TA 77 1 E REP ROD UCTION\\n205\\n292. Perianth. The perianth is not present in any\\ngymnosperms (If 281), except in a rudimentary form in a\\nfew species of the highest order. In angiosperms the\\nb E b\\nFig. 166. Pollen grains. A white water lily (Nymphcea alba). B, a thistle (Cirsium\\nneitiorale). C, a mallow {Hibiscus ternatus). D, dandelion {Taraxacum offi-\\ncinale). Magnified 200 diam. After Kerner. E, pine, showing bladdery enlarge-\\nments, b, b, of the outer layer of the cell-wall. Magnified 400 diam. After Stras-\\nburger.\\nperianth, which is rarely wanting, is primarily for the protec-\\ntion of the stamens and pistils. As in all cases where leaves\\nare produced rapidly and close together on a short axis, they\\ngrow during their early stages more\\nrapidly upon the outer face than the\\ninner. They are, therefore, concave in-\\nward and closely pressed together, form-\\ning a bud. At a certain stage the growth\\nupon the two faces becomes equal, and\\nlater is more rapid upon the inner face\\nthan the outer. At this time the flower\\nunfolds, the perianth spreading more or\\nless and exposing the stamens and pistils\\nwithin. These variations in growth are\\noften repeated, the stimulus being light\\nor heat or both, when it is necessary to protect the spores\\nagainst unfavorable weather. Such flowers open and close\\nseveral times before their leaves wither. (See also 244.)\\nFig. 167. Pollen mass\\nfrom an orchid. The\\npollengrainsare arranged\\nin packets, which are\\naggregated at the end of\\na stalk, cd, terminating in\\nan enlarged sticky disk,\\ng, by means of which the\\npollen mass adheres to\\ninsects. Magnified about\\n10 diam.\u00e2\u0080\u0094 After Engler.", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0211.jp2"}, "212": {"fulltext": "206 OUTLINES OF PLANT LIFE.\\n293. Calyx and corolla. The leaves of the perianth are\\nusually arranged upon the torus in two or more circles or in\\na low spiral. They may be all alike or differentiated into\\ntwo series, an outer and an inner. In the latter case those\\nof the outer row or rows constitute the calyx, and the inner\\nset the corolla.\\nThe calyx leaves, or sepals, are generally green and show a\\ngreat variety of form. When separate, the sepals are usually\\nsessile and broad, with more or less pointed apex. The\\nsepals are often apparently united, the originally separate\\nportions appearing as teeth or lobes at the rim of a cup or\\ntube, or some similar structure. Occasionally the sepals are\\nnot persistent, but fall as the bud opens or shortly thereafter.\\nMore commonly, however, the calyx, especially when un-\\ndivided, remains throughout the entire development of the\\nflower, and often of the fruit.\\nThe inner set of perianth leaves, the petals, constitutes the\\ncorolla. The corolla presents a greater variety of form and\\ncolor than does the calyx.\\nThe corolla is ordinarily not persistent, usually falling or\\nwithering shortly after the microspores have been lodged\\nupon the stigma.\\n294. Irregularity. The parts of both corolla and calyx\\nare often of equal size and like shape, and may be divided\\ninto several like halves by radial planes (figs. 168, 169).\\nBut often the symmetry of the calyx, and still more fre-\\nquently that of the corolla, is so altered by unequal growth\\nof the parts that the flower can be divided into like halves by\\nonly one, or at most two, planes; or it may even be entirely\\nunsymmetrical. This unlikeness in the size and shape of the\\naccessory leaves not infrequently extends to the stamens and\\npistils (figs. 170, 171).\\nThe irregular form and color of the perianth (when other\\nthan green), including the variegation of the ground color", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0212.jp2"}, "213": {"fulltext": "EGE TA TIVE REP ROD UCTION.\\n207\\nby lines and spots, seem to be dependent upon the relation\\nof the flower to insects. (See further 390.)\\nFig. 168. Fig. 169.\\nFig. 168. A flower of the flax, halved showing radial symmetry. See fig. 169. Mag-\\nnified 2 diam. After Bessey.\\nFig. 169. Diagram showing the arrangement of the parts of a flower of flax. Outer\\ncircle, 5 sepals second, 5 petals third, 5 stamens fourth, 5 carpels, each divided by\\na false partition into 2 chambers. Five different radial planes will, therefore, divide\\nthis flower into halves. After Bessey.\\n295. Pollination. To bring about the formation of a\\nnew plant within the ovule the pollen spores must lodge near\\nFig. 170. Fig. 171.\\nFig. 170. An unopened flower of the sweet pea, halved showing bilateral symmetry\\n(irregularity). Slightly enlarged. After Bessey.\\nFig. 171.\u00e2\u0080\u0094 Diagram showing the arrangement of the parts of the flower of sweet pea.\\nOuter circle, calyx (5-lobed) second, 5 petals, the two lower united third, 10 stamens,\\n9 united by filaments, 1 separate center, one carpel. Only one plane will divide this\\nflower into halves.\u00e2\u0080\u0094 After Bessey.\\nthe ovule and develop. To insure this a portion of the pistil\\nforms a receptive surface, the stigma, to which the pollen\\nspores readily adhere. It is advantageous, also, to have the", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0213.jp2"}, "214": {"fulltext": "2o8\\nOUTLINES OF PLANT LIFE.\\npollen spores of one flower lodged upon the stigma in\\nanother flower of the same sort rather than upon the stigma\\nd c\\nFig.\\nFig.\\n7 2 f ig. 173.\\nFig. 172.\u00e2\u0080\u0094 The torus of a flower of stonecrop {Sedum ternatuni), with the leaves re-\\nmoved to show scars two leaves of each kind shown, a, sepal; b, petal c, stamen\\nd, carpel. Magnified several diam.\u00e2\u0080\u0094 After Gray.\\nFig. 173. Flower of mousetail (Myosurus minimus), halved; showing s, spurred\\nsepal st, stamen si a staminode or sterile stamen, having the position and form of\\na petal t, elongated torus covered with carpels, some of which are cut through,\\nshowing enclosed ovule. Magnified several diam.\u00e2\u0080\u0094 After Engler.\\nFig. 174.\u00e2\u0080\u0094 Flower of the strawberry, halved showing elongated and thickened torus,\\ncovered with carpels. Magnified about 3 diam. After Bessey.\\nof the same flower. The process of transfer and lodgment\\nof pollen on a stigma is called pollination. If the pollen\\nfrom one flower is carried to the pistil of another, it is called", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0214.jp2"}, "215": {"fulltext": "VEGETATIVE REPRODUCTION. 2CX)\\ncross-pollination.* To secure pollination, and especially\\ncross-pollination, the agency of wind or water or insects is\\nemployed. To the peculiarities of these various agents,\\nflowers adapt themselves in character of pollen, color, nectar,\\nodor, form of parts, time of deveolpment of stamens and\\nstigma, etc. For an account of these see 383-394-\\n296. The torus. In the vicinity of the flower leaves the\\ninternodes of the stem are rarely developed, so that the nodes\\nfrom which the flower leaves arise are close together. More-\\nFig. 175. Fig. 176.\\nFig. 175. Flower of sweetb^er rose, halved showing urn-shaped torus. Compare fig.\\ngo. Natural size.\u00e2\u0080\u0094 After Bessey.\\nFig. 176. The inflorescence of a fig, halved lengthwise showing common torus on\\nwhose interior surface many flowers are formed. Two fig wasps are near the opening\\nof the flower chamber, one outside, while the other has just crawled in among the\\nflowers. Natural size. After Kerner.\\nover, the axis is usually enlarged, so as to give greater space\\nfor the numerous leaves. This enlarged portion is called the\\nreceptacle or torus. When the leaves are removed or fall\\nnaturally the torus shows ordinarily a rounded or conical\\nsurface, with close-set scars left by their bases (fig. 172).\\nSince fertilization of the egg is the ultimate object of pollination and\\ngenerally its final result, the terms close- or self-fertilization and cross-\\nfertilization were formerly used. The word pollination is preferable.", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0215.jp2"}, "216": {"fulltext": "210 OUTLINES OF PLANT LIFE.\\nWhen a great number of spore leaves are to be borne, the\\ntorus is elongated, as in the mousetail (fig. 173); or greatly\\nenlarged, as in the strawberry (fig. 174); or transformed into\\na cup, as in the rose (fig. 175).\\nWhen flowers in large numbers are very closely associated,\\nas in the sunflower and its allies, the receptacles are joined\\nto form a large common receptacle. The receptacle in such\\nplants may be a cone, a dome, or a more or less flattened\\ndisk. In the fig the common receptacle is pear-shaped, with\\nthe edges almost meeting above and the flowers distributed\\nover the inner face of the fleshy sac (fig. 176).\\nEXERCISE XLV.\\n1. Bisect a flower of marsh marigold lengthwise. Observe the three\\nsorts of leaves, perianth, stamens, and carpels their relation to each\\nother and their insertion separately on the enlarged stem, the torus.\\nSeparate some from an old flower and note the scars left by their fall.\\n(1 278.)\\n2. Are perianth leaves similar, or of two sorts? 293.)\\nDissect off a stamen. Observe the two parts (a) the slender stalk,\\nfilament, and (0) the enlarged part, anther. Note in the anther the two\\nlobes, each with a shallow groove marking the position of the two pairs\\nof spore cases. Tear open the spore case with a needle and observe the\\ninnumerable pollen grains which they contain. Examine a naturally\\nbursted anther and determine how they open. 287-289.)\\nDissect off and examine a pistil. 282.) Observe\\n3. At the apex the roughened area, the stigma 283), sessile upon\\n4. The enlarged part, the ovulary. Observe its flattened form and\\nthe grooves along one edge. Split it along this line, flatten it out care-\\nfully and note the ovules attached to the edges. 286.)\\n5. Cut several transverse sections of the pistil and observe the thick-\\nened edges of the carpel, forming the placenta, to which ovules are at-\\ntached. Compare sections. Are all ovules attached to same edge\\n6. Study and compare the flowers of the sweet pea {Lathyrus odora-\\ntus), apple, fuchsia, and garden lily.", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0216.jp2"}, "217": {"fulltext": "VEGE TA Tl VE RE PROD UCTION.\\n211\\nIII. Brood buds, etc.\\n297. Simple forms. In their simplest form brood buds\\nconsist of a single cell, though more commonly they are two-\\nto several-celled. Like spores, they are supplied with re-\\nserve food. The shape of brood buds is various. When not\\nfurnished with distinct organs, they are club-shaped, lentic-\\nular, or spherical. In some thalloid liverworts {Marchantia\\nand Lunularia) they are produced on the surface of the thal-\\nlus, surrounded wholly or on one side by an outgrowth from\\nthe surface forming a cup or a crescentic ledge (figs. 39,\\n177). In some mosses brood\\nbuds arise from the apex of the\\nstem, either in cup-like clusters\\nof leaves or exposed (A, A fig.\\n178) in others they are smaller\\n^MhJf\\ntS^\\nA\\nFig. 177. Fig. 178.\\nFig. 177.\u00e2\u0080\u0094 Thallus of Marchantia, seen from above, showing the cups containing brood\\nbuds. Natural size \u00e2\u0080\u0094After Kerner.\\nFig. 178. Brood buds of mosses. A, upper part of the stem of Aulacomnium an-\\ndrogynum, with a cluster of brood buds at apex (magnified about 8 diam.), one of\\nwhich is enlarged 120 diam. in A B, tip of leaf of SyrrJiopodon scaber (magnified\\nabout 10 diam.) showing brood buds B some more enlarged (about 40 diam.). After\\nKerner.\\nand simpler and are developed upon the leaves B fig.\\n178). In all the mossworts they belong to the gametophyte.\\n298. Shoots. In fernworts and seed plants the brood\\nbuds are especially abundant, and often reach considerable", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0217.jp2"}, "218": {"fulltext": "212\\nOUTLINES OF PLAN 7 LIFE.\\nsize and complexity before being separated from the parent\\nplant. They usually consist of a short axis with a growing\\nFig. 179. Young plants developing from adventitious buds on leaves of a fern (As/ le-\\nnium bulbiferum) from which they readily separate to form new plants. A, natural\\nsize. B, magnified 2 diam. After Kerner.\\npoint and at least rudimentary leaves. They generally arise\\nupon the stem, more rarely from the leaves or the root (fig.\\n179). Upon the stem they usually\\ntake the place of shoots of other forms,\\ndeveloping from axillary buds (figs.\\n180, 182). If formed on leaf or root\\nit is always from adventitious buds.\\nEvery possible gradation exists, from\\nthe simplest to those with well-devel-\\noped members, constituting a plant of\\nsome size. They may be artificially\\ngrouped as follows\\n299. (a) Buds. In these the axis is\\nshort and the leaves scale-like. When\\nFig ,80\u00e2\u0080\u0094 Fleshy buds in axils mos t highly developed the quantity\\nof the leaves of a lily (Lili- J l i. J\\nof reserve food is considerable and the\\nparts of the bud are often distorted\\nby enlargement to contain the food. The fleshy buds which\\num bulbi/eruni). Some-\\nwhat reduced. After Van\\nTieghem.", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0218.jp2"}, "219": {"fulltext": "V EG ETA TIVE REP ROD VCTION.\\n213\\nreadily separate from the axils of the leaves of some garden\\nlilies (fig. 180), and those which replace the flowers in some\\ncultivated onions, are well known. (Compare also fig. 68.)\\nFig. 181. Pond weed (Potamogeton crispiis). Detachment of special shoots, hiber-\\nnacula, which are to hibernate under water. The plant A has one of these shoots at\\nthe tip B has just loosened one, h, which is sinking to the bottom. Two thirds natural\\nsize.\u00e2\u0080\u0094 After Kerner.\\n300. {b) Winter shoots. Somewhat similar but more\\nhighly developed brood buds are formed at the approach of\\nwinter about the base of the stem in many perennials with\\nherbaceous tops. These are separated by the death of the\\nparent stem and produce new plants in the spring. Some\\naquatics show a similar habit, dropping short shoots to the\\nbottom of the water in autumn, which are to grow in the\\nspring (fig. 181).\\n301. (c) Offsets, etc. Some plants produce special\\nbranches, either underground or aerial, which develop at\\ntheir extremities new plants, or special structures for their", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0219.jp2"}, "220": {"fulltext": "214\\nOUTLINES OF PLANT LIFE.\\nformation. The house-leek or live-for-ever (fig. 207) and\\nstonecrop (fig. 182) reproduce themselves by offsets. These\\nare short branches with a rosette of leaves at the tip which\\nare readily detached and roll away, to take root at the first op-\\nportunity and establish a new plant.\\nThe strawberry forms long leafless\\nbranches which take root at the tip\\nand produce new plants, the slender\\nrunner subsequently perishing (fig. 0\\n183). The white potato forms at the\\nend of slender underground branches\\nelongated tubers upon which are\\nnumerous buds, any one of which,\\nnourished by the reserve food in the\\ntuber, may produce a new shoot.\\nThe slender stem by which the tuber\\nFig. 182 \u00e2\u0080\u0094A plant of stonecrop (Sedum dasyphyllum) Offsets are produced near\\nthe base on short branches O, O at the tip of longer branches, O and in place of\\nthe flowers, O Natural size.\u00e2\u0080\u0094 After Kerner.\\nis connected with the main axis perishes at the end of the\\ngrowing season (fig. 184).\\n302. (d) Cuttings or scions. Closely related to this\\nmode of reproduction is that by the separation of fleshy\\nmembers, upon which later are developed adventitious buds\\nthat give rise to new plants. The thick leaves of Bryophyl-\\nlum are often blown off by storms, and produce new plants\\nfrom buds formed at the teeth along the edge. Some species\\nof Kleinia, natives of Cape Colony, have fleshy stems, jointed", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0220.jp2"}, "221": {"fulltext": "V EG ETA T1VE RETROD UCTION.\\n215\\nat intervals, so that they easily break there. When broken\\noff by an accident, the piece rolls away, takes root from the\\nunder side, and sends up shoots from the upper.\\nAdvantage is taken of this power of several parts to form\\nadventitious roots and shoots in the artificial propagation of\\nFig. 183. Formation of runners in the strawberry, a, the mother plant b, young plant\\nformed at tip of first runner c plantlet at tip of second a third has put out from c.\\nSlightly reduced. After Seubert.\\ndomestic plants. Suitable portions of shoots or leaves for\\nthe development of new plants under proper conditions are\\ncalled cuttings, scions, or buds. They may generally be\\ngrown in water or soil or they may be securely fastened in\\na slit or wound in another plant. The latter process is\\nknown as grafting or budding, according to the form of the\\nimplanted part. Indeed brood buds in general may be\\nlooked upon as natural cuttings or scions.\\n303. Summary. Vegetative reproduction is usually ac-\\ncomplished by the formation of small bodies which at matu-\\nrity separate from the parent and grow into new plants. In\\nthe simplest plants the process consists of a separation of the", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0221.jp2"}, "222": {"fulltext": "2l6\\nOUTLINES OF PLANT LIFE.\\nparent into nearly equal parts, each of which then continues\\nto grow. In most plants the bodies separated are small or\\nminute, compared with the parent. They are either spores\\nFig. 184.\u00e2\u0080\u0094 A seedling potato plant, c is the base of the stem, below which is the primary\\nroot, r. The primary leaves ct, are still present. The early leaves,,/, are not so.\\nmuch branched as later ones will be. In the axils of the lower leaves arise the\\nbranches b, with scale leaves, e c, and secondary roots, The tips of these branches,\\nwhen illuminated, bear foliage leaves,/ but usually they thicken into tubers, tb,\\nwhich have scale leaves, e c in whose axils buds, br, are formed, the so-called eyes\\nof the tuber. Natural size. After Duchartre.\\nor brood buds. Spores of water plants are often motile\\nthose of some water plants and most land plants are not, but\\nmust be distributed by winds, water, or animals. The\\nspores are formed singly or in chains at the tips of special", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0222.jp2"}, "223": {"fulltext": "VEGE TA Tl VE REP ROD UCTION. 2 1 7\\nbranches or they are produced in spore cases, which break\\nor are broken to set free the spores. The parts producing\\nthe spores are usually numerous and are closely associated.\\nIn the fernworts and seed plants the spore cases are usually\\nformed on specialized leaves. When such leaves are clus-\\ntered on a short stem, and especially when they are accom-\\npanied by colored accessory leaves, they form a flower. The\\naccessory leaves form the perianth (calyx and corolla) and\\nthe spore-bearing leaves are the essential organs (stamens\\nand pistils). The stem from which they grow, the torus, is\\noften enlarged when the leaves are numerous.\\nBrood buds are usually larger and more complex than\\nspores. In the lower plants they show no distinct members.\\nIn the fernworts and seed plants they often have rudiments\\nof leaves and stems. Similar, but more developed parts, are\\nseparated by some plants to form new individuals. Propa-\\ngation by cuttings, grafting, and budding is merely an imita-\\ntion of natural methods.", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0223.jp2"}, "224": {"fulltext": "CHAPTER XVIII.\\nSEXUAL REPRODUCTION.\\n304. Cell union. All methods of sexual reproduction\\nconsist in the formation of a single cell by the union of two\\nspecialized cells, known respectively as the male cell, or\\nsperm, and the female cell, or egg, neither of them capable\\nof growing further without such union.\\nThe organs and processes of sexual reproduction in plants are scarcely\\nvisible except with the microscope, and therefore will not be further dis-\\ncussed here. (See the author s riant Life.\\nThe cell formed by sexual union is capable of developing\\ninto a new plant under suitable conditions. It may grow at\\nonce into a new plant, or it may remain dormant for a longer\\nor shorter time. If it remains dormant it forms a resting spore.\\nTo protect itself, it thickens its wall, often very greatly.* It\\nmay then escape from the parent, but more commonly re-\\nmains enclosed until set free by the death and decay of the\\nparent. In the other case, the spore develops at once.\\nExcept in the brown seaweeds, whose eggs are ejected into\\nthe water before union of the sperms with them, the spore\\nremains enclosed in the parent, within which it begins to\\nform a young plant, the embryo.\\n305. Seed. In all but the seed plants the development of\\nthe embryo is uninterrupted until a mature plant is formed.\\nThick-walled resting spores are also formed vegetatively.\\n213", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0224.jp2"}, "225": {"fulltext": "SEXUAL REPRODUCTION. 2IO.\\nIn seed plants the embryo, which forms within an ovule (see\\nT 280), and stimulates it to renewed growth, develops to a\\ncertain stage and then ceases to grow. With suitable protec-\\ntion and food supply, it is then cast\\noff as a seed, and, usually after a\\ndormant period, continues its de-\\nvelopment until mature. The ripe\\nseed consists of the following parts:\\n(1) In the interior, occupying\\nvarious positions and of exceeding-\\nly variable relative size, is the FlG l8s _ Seed of pansy; en tire and\\nembryo. (2) Immediately around K$ f^T^^SS^\\nK^.\u00e2\u0080\u009e \u00e2\u0096\u00a0_\u00e2\u0096\u00a0 (white and dotted 1. the seed-coats\\nit lies a tissue containing reserve U, micropyie. Magnified about 10\\nfood, but this may be so shrunken diam After Baillon\\nand emptied as to be recognizable only by microscopic\\nexamination. In that case the reserve food will have been\\nabsorbed by the embryo itself, which is then likely to be\\nlarge and to occupy most or all of the space\\nwithin the seed coats. (3) Upon the exterior\\none or two seed coats, more or less readily distin-\\nguishable from each other (figs. 185, 186).\\nFl S l86 okeb S e e iS! Induced result of cell union.\\nPhytola cca\\ndecandra), 306. Fruit. The growth of the embryo\\nhalved show- J\\ning curved em- excites not only the ovule to further develop-\\nbryo next the y A\\ntwo seed-coats me nt, but also the carpels which bear the ovules,\\nand nearly sur-\\nrounding the an d no t infrequently even more remote parts.\\nendosperm. x J x\\nMagnified The carpels and their contents and adherent\\nabout 10 diam. x\\n\u00e2\u0080\u0094After Baillon. p ar ts, when fully developed, constitute the fruit.\\nThe carpels are then known as the pericarp. The changes\\nwhich the parts undergo are chiefly of two sorts an increase\\nin size and an alteration of texture. The increase in size re-\\nquires no special explanation. The carpels may become\\ndry at maturity, or may thicken and become soft and fleshy,", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0225.jp2"}, "226": {"fulltext": "220\\nOUTLINES OF PLANT LIFE.\\nor even juicy. In accordance with these differences,, two sorts\\nof fruits are recognized, namely, dry fruits and fleshy fruits.\\nBetween these, however, there is no sharp Une of demarca-\\ntion.\\n307. Dry fruits. If the pistil contain only one or two\\nseeds, it very often does not open at maturity. Consequently,\\nthe seed-coats ordinarily remain thin, and the protective\\nfunction is put upon the pericarp. In some cases the carpels\\nbecome adherent at an early stage to the surface of the ovule,\\n12 34\\n187. A small portion from the margin of a transverse section of grain of oats,\\n1, 2, pericarp; 3, seed-coats; 4, remains of the sporangium; 5-7, endosperm; 5,\\ngluten cells 6, cells containing large compound starch-grains (compare fig. 114) at\\n7, richer in gluten, with less starch. Magnified about 325 diam.\u00e2\u0080\u0094 After Harz.\\nand at maturity the pericarp is so firmly attached that it can\\nscarcely be distinguished from the seed-coats themselves.\\nSuch a change takes place in the fruit of most grasses, and the\\ngrain so formed is ordinarily mistaken for a seed (fig. 187).\\nWhen dry fruits are one-seeded and indehiscent the pericarp\\nusually bears whatever special contrivances are necessary for\\nthe distribution of the seeds. (See further ^f 395 ff. If,\\nhowever, the pericarp contains many seeds, it generally breaks\\nat maturity to allow the loosened seeds to escape. The ex-\\ntent and position of the opening into the seed chamber or", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0226.jp2"}, "227": {"fulltext": "SEXUAL REPRODUCTION. 221\\nchambers are exceedingly various. In some cases the open-\\nings are so small as to be mere slits or pores (fig. 188). In\\nothers a more or less circular line of breakage forms a little\\ndoor or valve which opens and closes with changes of moisture\\n(fig. 189). In other cases the pericarp splits lengthwise into\\nFig. 189.\\nFig. 188. Ripe capsules of a wintergreen (Pyrola cklorantha showing dehiscence\\nby pores. The opening is a short split at the middle of the base of each carpel.\\nNatural size. After Kerner.\\nFig. 189.\u00e2\u0080\u0094 Ripe capsules of a bellflower {Campanula rapunculoides), showing small\\nreflexed valves. Natural size.\u00e2\u0080\u0094 After Kerner.\\ntwo or more pieces (fig. 190), or, less often, cracks trans-\\nversely so as to loosen a lid (fig. 191).\\n308. Fleshy fruits. The changes which produce fleshy\\nfruits consist in a transformation of certain parts of the peri-\\ncarp into masses of thin-walled juicy cells. Other parts may\\nremain unchanged, or may even become hardened. The\\ninner part of the pericarp sometimes becomes of a stony hard-\\nness, while the outer portion becomes soft and juicy. Such\\nchanges produce a fruit like that of the peach or the cherry.\\nThe pericarp encloses a single seed with delicate brown seed-\\ncoats whose protective function has been completely usurped\\nby the stone (fig. 192). In other cases, while the inner face\\nbecomes stony, the outer becomes fibrous, tough, and dry, as", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0227.jp2"}, "228": {"fulltext": "222\\nOUTLINES OF PLANT LIFE.\\nin the almond, walnut, and hickory nut. The outer part in\\nthe last even breaks regularly into four pieces. Such fruits\\nP iG. 190. A, capsule of violet split open at maturity, the seeds still attached to the\\nplacentae. B, three pods of Lotus corniculatus a, just beginning to crack; t\\nsplit throughout, with the pieces somewhat twisted c, empty of seeds, the two pieces\\nfully dried and twisted. Natural size.\u00e2\u0080\u0094 After Baillon.\\nfurnish a transition from the most perfect fleshy fruits to the\\ndry fruits. In other cases the placentas become very much\\nenlarged, and the whole of the pericarp\\nbecomes fleshy, as in the tomato. In\\nothers the outer part of the pericarp is hard\\nand firm, while the inner becomes pulpy,\\nas in the pumpkin and squash.\\n309. Accessory fruits. Parts adjacent\\nto the carpels, either flower leaves or axis\\nor both, stimulated to growth, frequently\\nFig. 191.\u00e2\u0080\u0094 Ripe capsule\\nofpimpemeii04\u00c2\u00bbrt\u00c2\u00a3vi/- enter into the formation of fleshy fruits.\\nlis arvensis), opening\\nby a lid. Magnified These may be accompanied by either a\\nseveral diam. After\\nBaillon. fleshy or a dry pericarp. In the winter-\\ngreen berry the calyx grows thick and fleshy and surrounds a\\ndry pericarp, which cracks at maturity (fig. 193).", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0228.jp2"}, "229": {"fulltext": "SEXUAL REPRODUCTION.\\n223\\nFir.\\nFruit of the cherry,\\nhalved, e, epidermis of peri-\\ncarp m, fleshy layer of\\npericarp en, stony layer of\\npericarp s, seed cot, one\\nof the pair of thickened seed-\\nleaves of embryo. Natural\\nsize. After Focke.\\nIn the strawberry (fig. 174) the torus becomes greatly enlarged\\nand fleshy, while the minute, one-seeded, dry fruits are scat-\\ntered over its surface, imitating small\\nseeds. The fig has the same parts,\\nwith the torus concave, instead of\\nconvex (fig. 176). The apple consists\\nof a fleshy torus carrying at its free\\nend the withered calyx and enclosing\\nthe tough, thin pericarp (fig. 194). In\\nthe blackberry the receptacle becomes\\nfleshy, and each pistil forms a minute\\nfruit like a cherry, adherent to its\\nneighbors and to the pulpy torus.\\nThe raspberry is like it, except that\\nthe adherent mass of fruits separates\\nas a cap from a firm torus (fig. 195).\\n310. Multiple fruits. If the flowers are crowded, either\\ndry or fleshy fruits resulting from them may be closely\\ncrowded at maturity. Under these conditions fleshy fruits\\nfrequently become adherent, and may thus constitute a\\nmultiple fruit quite similar in form to the fruit\\nformed by the aggregated carpels of a single\\nflower. Compare the multiple fruit of the\\nmulberry (each section from a separate flower\\nwhose floral leaves and pistil both become\\npulpy; fig. 196) with such an aggregate fruit\\nas the blackberry, in which each section is one\\npistil out of the many belonging to a single\\nflower (fig. 195). The pineapple is similar to\\nthe mulberry in origin.\\nEven more remote parts are stimulated to\\ndevelopment by fertilization of the egg. The\\nstem bearing the flower generally grows and\\nbecomes stronger, to carry the fruit, especially if large. The\\nFig. 193.\u00e2\u0080\u0094 Fruit\\nof wintergreen\\n(Ga ultheria\\nfir o c u ibe?is),\\nhalved, showing\\nthin (dry) peri-\\ncarp, surround-\\ned by thickened\\nfleshy calyx.\\nMagnified\\nabout 2 diam.-\\nAfter Gray.", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0229.jp2"}, "230": {"fulltext": "224\\nOUTLINES OF PLANT LIFE.\\nminute bractlets sometimes become highly developed beneath\\nthe fruit. The cup of the acorn and the husk of the hazle-\\nnut originate in this way as the nuts form. The similar husk\\nof the beechnut and chestnut encloses more than one fruit.\\nFig. 194.\u00e2\u0080\u0094 Fruit of the apple. A, halved longitudinally; B, halved transversely.\\nericarp, enclosing seeds g t vascular bundles of the fleshy torus entering k, the calyx\\neaves. One half natural size.\u00e2\u0080\u0094 After Focke.\\nFig. 195. Fig. 196.\\nFig. 195. Vertical section of a flower of raspberry (Rubus uieeus), showing numerous\\npistils which form the caplike fruit over the enlarged torus stamens, corolla, and\\ncalyx all united at base. Magnified about 2 diam.\u00e2\u0080\u0094 After Kerner.\\nFig. 196. A, pistillate flower cluster of white mulberry; B, multiple fruit from same.\\nNatural size.\u00e2\u0080\u0094 After Baillon.\\n311. Distributive arrangements. The young of all plants\\nmust be so scattered as to prevent them from coming into\\nsharp competition with the parents. In seed plants this dis-\\ntribution occurs at the time of maturity of the seed, i.e., when\\nthe embryo has become dormant, and the food store and pro-", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0230.jp2"}, "231": {"fulltext": "SEXUAL REPRODUCTION. 22$\\ntective coverings have been completed. The devices by\\nwhich seeds are scattered are dependent upon the number and\\ncharacter of the seeds and the nature of the pericarp. Plants\\nadapt themselves so as to employ as distributing agents wind,\\nwater, and animals, or they develop special mechanisms for\\ncasting off the seed as a projectile. A consideration of these\\nadaptations belongs to ecology. (See Chap. XXVI.)\\n312. Renewed growth. After a time, if the seeds become\\nwet and are kept at a suitable temperature, with a supply of\\nair, the embryo resumes its growth, i.e., the seed germi-\\nnates. This growth soon bursts the seed coats the food is\\ndigested and absorbed the young plant sends its roots into\\nthe soil and its leaves to the light, and by the time the food\\nstore is exhausted, is ready to make its own living.\\n313. Summary. Sexual reproduction consists in the\\nunion of a male cell and a female cell (neither able to grow\\nfurther) to form a single new cell capable of growing into a\\nnew plant. The processes and organs are not described here.\\nThe direct result is the formation of a resting spore which\\nremains dormant for a time or else the immediate develop-\\nment of an embryo plant. In the latter case the embryo, in\\nall but seed plants, continues its growth, interrupted only by\\nexternal conditions, until it becomes a full-grown plant. In\\nthe seed plant it becomes dormant while still small. Before\\nits growth is interrupted, its development has induced the\\ngrowth of the ovule, in which it lies, until the two form the\\nripe seed. Adjacent parts also grow and with the seed con-\\nstitute the fruit. The changes in the growing parts produce\\ndry, fleshy, accessory, or multiple fruits. The seeds are finally\\nscattered by various ingenious devices. With a suitable sup-\\nply of heat, air, and water, the embryo resumes its growth\\nand continues to grow until it forms a mature plant.", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0231.jp2"}, "232": {"fulltext": "PART IV ECOLOGY.\\n314. Definition. Physiology, in its broadest sense, may\\nbe divided into physiology proper and ecology. Ecology is\\nthat portion of botanical science which treats of the relations\\nof the plant to the forces and beings of the world about it,\\nas distinguished from physiology proper, which treats of the\\nrelations of the plant as a whole to the chemical and physical\\nforces within it. The forces without the plant necessarily\\nlimit and modify the action of the forces within it conse-\\nquently it is quite impossible to draw a sharp distinction be-\\ntween those subjects which belong to ecology and those which\\nbelong to physiology proper. Parts II and IV, therefore, will\\nbe found to overlap in many places. Several of the subjects\\nalready treated under physiology belong in part to the present\\nsection. For example, the movements of plants are due not\\nto internal causes alone, but to internal causes as modified by\\nexternal conditions. In this part only a bare outline of the\\nadaptations of plants in form and habit to their physical sur-\\nroundings and to other living beings can be given.\\n226", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0232.jp2"}, "233": {"fulltext": "I. NUTRITIVE ADAPTATIONS.\\nI. ADAPTATIONS OF FORM AND STRUCTURE TO\\nENVIRONMENT.\\nCHAPTER XIX.\\nFORMS OF VEGETATION.\\n315. Adaptation. The various physical conditions which\\nmake up the climate of any particular region of the earth s\\nsurface, together with the nature of the material upon or in\\nwhich the plant grows, largely control the form and functions\\nof the plants found in that region. Stated in other words,\\nplants, in order to exist at all, are compelled to adapt them-\\nselves to the places in which they grow. This compulsion is\\non pain of death.\\n316. The struggle for existence. The competition be-\\ntween plants is intense. Only a very small portion of the\\nseedlings which start in any particular area can come to ma-\\nturity. Far the greater number will be killed by being robbed\\nof light and of water by the overshadowing leaves and inter-\\nlacing roots of their companions. Since such competition\\nexists, it is evident that only those best suited to the condi-\\ntions under which they grow will have any chance whatever\\nto survive.\\nNot only are individuals subject to this competition, but\\nall individuals of a particular kind (a species) may be de-\\nstroyed in any region through the competition of other\\n227", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0233.jp2"}, "234": {"fulltext": "228 OUTLINES OF PLANT LIFE.\\nspecies better suited to the conditions of that region.\\nThrough this competition between species one kind may be\\nforced to migrate to some different region in order to main-\\ntain itself. The capacity of a plant to adapt itself to differ-\\nent surroundings determines the possibility of its occupying\\na new region, for here it must come into competition with\\nother sorts, and can only maintain itself if it is capable of so\\nmodifying its form and structure as to adapt them to the new\\nconditions, and that, at least as well as the occupants it finds\\nin possession. In the beginning it was probably by competi-\\ntion between species that water plants were gradually forced\\nto adapt themselves to an amphibious life, and then to a ter-\\nrestrial life, all the while advancing in complexity later some\\ngreen plants adapted themselves to a parasitic or saprophytic\\nlife plants of moist regions gradually moved out and occu-\\npied even the deserts plants loving the shade adapted them-\\nselves to the direct light of the sun and so on, until all\\nparts of the earth s surface and even considerable depths of\\nthe ocean have been occupied.\\n317. Environment. In order to understand the variety of\\nfactors which are acting upon any particular plant, it will be\\ninstructive to consider the conditions which surround the or-\\ndinary land plant. A portion of such a plant is embedded in\\nthe soil, and the remainder rises into the air. The subterra-\\nnean part is profoundly influenced by the size and form of the\\nsoil particles, as well as by their chemical composition. It\\nis exposed to contact with water varying in amount, some-\\ntimes from day to day and always from time to time during\\nthe year, holding many substances in solution in varying\\namounts and kinds at different periods. It is subject, also,\\nto variations of temperature from day to day and from season\\nto season.\\nThe aerial part of such a plant is exposed to greater or less\\nvariations of temperature from hour to hour, from day to", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0234.jp2"}, "235": {"fulltext": "FOfiMS OF VEGETATION. 229\\nnight, from day to day, and from season to season. It is\\nexposed to light varying in intensity from day to night, and\\nfrom day to day, and to light differing in direction from hour\\nto hour of each day. It is enveloped by fogs or mists, or is\\npelted by rain, hail, sleet, or snow, and sometimes completely\\nburied in ice or snow.\\nA plant has little or no power to alter any of the agents\\nwhich act upon it, but it must be able to withstand the injuri-\\nous ones, or even to turn them to its advantage. It would\\nbe difficult to conceive a more complex set of factors to\\nwhich adjustment must be effected and the more, since these\\nconditions are combined with each other in an infinite\\nvariety of ways. Because the physical conditions vary in\\ndifferent parts of the earth s surface, the vegetation in each\\nregion differs from that in others.\\nIn any particular locality certain conditions of water, soil,\\nair, temperature, light, and rainfall are likely to be associated.\\nIt is possible, in a somewhat arbitrary way, to recognize four\\ngeneral sets of conditions to which plants must adapt them-\\nselves, in each of which the relation to water is the dominant\\nfactor. It should be understood clearly, however, that these\\nsets of conditions pass into each other imperceptibly. Cor-\\nresponding to these four sets of external conditions, we may\\nrecognize certain characteristics in plant form and structure,\\nwhich are likely to be associated, and it thus becomes possi-\\nble to distinguish four forms of vegetation corresponding to\\nthe four sets of external conditions.\\n318. The first set of conditions consists of those charac-\\nacterized by no extremes. Both the air and the soil are mod-\\nerately moist; the rainfall is distributed through the year, or\\nat least through the growing season there is no excess of salts\\nin the water or in the soil the soil is usually enriched with\\norganic matter, often in considerable amount. The plants\\nwhich grow under these conditions are the ones most familiar", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0235.jp2"}, "236": {"fulltext": "23O OUTLINES OF PLANT LIFE.\\nto people in the fertile regions of temperate climates. These\\nmay be reckoned as the average, or mean, plants, and are\\ntherefore called technically mesophytes.\\n319. A second set of conditions is characterized by defi-\\ncient water supply throughout the year, the amount of water\\npresent in the soil often being less than 10$. Such regions\\nmay be considered as regions of continuous drought. The\\nplants adapted to these conditions are known as drought\\nplants, or xerophytes.\\n320. A third set of conditions, prevailing over compara-\\ntively limited regions, is characterized by an excess of salts in\\nthe soil or water. These salts are chiefly common salt, gypsum,\\nand magnesium chloride. Plants which can live under these\\nconditions are known as salt plants, or halophytes.\\n321. A fourth set of conditions is characterized by an\\nexcess of water. The plants grow wholly or partly sur-\\nrounded by water, or their roots are embedded in a soil\\nsupersaturated with water, that is, containing at least 80$.\\nSuch plants are called water plants, or hydrophytes.\\nIt will be noticed that the first three groups, namely, meso-\\nphytes, xerophytes, and halophytes, are essentially land plants\\nin distinction from the fourth group, which are water plants.\\n322. Summary. In order to exist at all, plants must\\nadapt themselves to the places in which they live. Compe-\\ntition for light, water, and soil room is intense because of the\\nnumber of individuals. Competition of better adapted kinds\\nmay exterminate or force migration. The factors to which\\nplants must adjust themselves are many. Each factor is more\\nor less variable and different factors may be combined in any\\nratio, producing almost infinite diversity. Plants differ,\\nchiefly because of this diversity of conditions under which\\nthey grow, For convenience the water relation is used to\\ngroup plants into four vegetation forms, mesophytes, xero-\\nphytes, halophytes, and hydrophytes.", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0236.jp2"}, "237": {"fulltext": "CHAPTER XX.\\nM E S O P H Y T E S\\n323. I. Mesophytes show certain general relations to ex-\\nternal conditions, many of which are also shared by other\\nforms. Except to these minor variations in the environment,\\nthey show no special adaptations or, rather, they are looked\\nupon as the normal plants, and the ways in which others\\ndiffer from them are spoken of as special adaptations. In\\nreality, however, the general methods by which they adapt\\nthemselves to their environment, which are now to be con-\\nsidered, are quite as much special adaptations as those shown\\nby plants living in extreme climates. These adaptations will\\nbe discussed in relation to each of the main factors of the\\nenvironment.\\n324. i. Air. The composition of the air varies little from\\nplace to place. It is only in those regions in which it is\\nrendered impure by artificial means, such as the vicinity of\\ncities and factories, and in the few isolated regions in which\\nit is vitiated by natural means, as in volcanic regions, that\\nany special adjustments may be looked for. Artificial vitia-\\ntion of the air kills off certain plants. A few plants have\\nadapted themselves to air in the neighborhood of fumaroles,\\nwhere they are subjected to vapors containing large amounts\\nof sulfurous acid. Whatever special adaptations are found\\nare internal, since only the very simplest plants find it pos-\\nsible to live in such conditions.\\n231", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0237.jp2"}, "238": {"fulltext": "232 OUTLINES OF PLANT LIFE.\\nThe movements of the air, however, influence profoundly\\nthe form of plants. This they do indirectly by the shifting\\nof sands in sandy regions, and by their effect upon the pre-\\ncipitation and upon the moisture of the atmosphere. Winds\\nincrease evaporation from the soil and from the surface of\\nplants, and thus directly influence form. Trees growing in\\nwind-swept regions are always low, bushy-branched, with\\nthe trunk and limbs inclined to leeward. The twigs on the\\nwindward side are often dead. Forests in wind-swept regions\\noften thin out to windward, the trees becoming smaller and\\nsmaller, finally being replaced by bushes which become\\nsparser until no woody vegetation is present. The leaves\\nupon such plants are small and often peculiarly spotted.\\nThese effects upon the form have been ascribed to the me-\\nchanical action of the air, to the presence of salts when in\\nthe neighborhood of the ocean or salt lakes, and to the re-\\nduced temperature but probably none of these causes is to\\nbe looked upon as so efficient as the drying brought about by\\nthe prevalent wind.\\n325. 2. Light. Light affects plants directly through its\\ninfluence upon their nutrition and upon the evaporation of\\nwater from their surfaces. In this way it affects i the rate\\nof development. For example, the blossoming of flowers\\nand the production of leaves occur earlier upon the sunward\\nside of a tree or shrub than upon the other side. In the\\nsame cultivated crops of the north and south there will often\\nbe several days difference in the total number between sow-\\ning and maturing. Thus barley at northern Norway, in 68\u00c2\u00b0\\nN. lat., matures in 89 days, while at Schonen, in 56 N. lat.,\\nit matures in 100 days. Since the total hours of illumination\\nmust be about equal, the longer days of the north enable the\\nplants to produce more food, and so to mature more rapidly.\\nThe forcing of vegetables under glass by the aid of electric\\nlight during the night depends upon the same principle. (2)", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0238.jp2"}, "239": {"fulltext": "ME SOPH YTES. 233\\nThe form of plant parts is directly influenced by light. Plants\\naccustomed to the direct sunlight and those accustomed to\\nshade show profound differences in habit. Light plants are\\nstocky and compact their stems are inclined to be woody,\\nthe leaves are usually folded or crisped and often set at an\\nacute angle with the direction of the light, and the surfaces\\nare frequently hairy. In contrast, shade plants are slender\\nand sprawling their stems often thin and weak the leaves\\nflat and smooth and set transverse to the direction of the light-\\nrays, while the surface is slightly, if at all hairy. (3) In inter-\\nnal structure, also, there are decided differences, particularly\\nin the leaves. These differences affect the skin, the number\\nand distribution of the stomata, the form of the cells, and\\ntheir contents. The sum of the differences distinguishes an\\nupper (illuminated) from an under (shaded) side.\\n326. 3. Temperature. Temperature exercises an im-\\nportant influence upon plants, both upon their aerial and sub-\\nterranean parts. The temperature of the air is really much\\nmore important in controlling the adaptations, and conse-\\nquently the geographic distribution, of plants than is light.\\nThe reason for this is to be found in the much more unequal\\ndistribution of temperature in various regions of the earth s\\nsurface. Moreover, temperature affects every vital function\\nof the plant, for each of which a maximum, minimum, and\\noptimum point may be determined. (See ^f 153, 219.) The\\nvariations in temperature to which plants are subjected require\\nspecial adaptations.\\n327. (a) Protection against changes of temperature.\\nThese adaptations are to be found in the presence of special\\nsubstances, such as oils or resins, which reduce the liability\\nof the parts containing them to freeze in the reduction of\\nthe amount of water in the plant so that less damage results\\nfrom freezing and, finally, in the presence of poor con-\\nductors of heat, such as scale-leaves and hairs in profusion,", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0239.jp2"}, "240": {"fulltext": "234 OUTLINES OF PLANT LIFE.\\na jacket of old withered leaves, etc., all of which insure slow\\nthawing if the plant is frozen. The winter buds of trees in\\ntemperate climates illustrate all of these adaptations.\\n328. A dormant period is necessitated by low tem-\\nperature during part of the year in temperate and arctic cli-\\nmates. The period of vegetation in the higher latitudes is\\noften very short. The same conditions prevail at high alti-\\ntudes, with the same effects. In these regions, therefore, the\\nplants are almost all perennials. In many cases the rudi-\\nments of flowers are formed in the year preceding that in\\nwhich they are developed, in order that full opportunity may\\nbe given for the ripening of the seeds and fruits in the short\\ngrowing season. Some plants adapt themselves to short\\nperiods of vegetation by the presence of evergreen leaves,\\nwhich are ready at the first opportunity to resume their work\\nof food manufacture.\\n329. (c) The form of plants is modified by the tem-\\nperature of the air and soil. Low temperatures are also\\nlikely to bring about the formation of dwarf plants.\\n330. (d) The rate of development is strikingly influenced\\nby variations in the temperature of the soil. The soil heat is\\nchiefly derived from the sun. The amount of heat absorbed\\nvaries with the exposure of the soil, its color, porosity,\\namount of water, and the duration of illumination. The\\ninfluence of the temperature of the soil is mainly indirect,\\nacting through its effect on the water supply of the plant.\\n331. 4. Moisture and precipitation. The amount of\\nmoisture in the atmosphere largely determines the amount of\\nevaporation from the surface of the plant. The relative\\namount of moisture in the atmosphere is exceedingly variable,\\nand bears a direct relation to its temperature. Indeed, so\\nclosely related are the conditions of temperature, light, and\\nmoisture in the air, that the adaptations of shade plants,\\nmentioned above, may be considered as the sum of the", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0240.jp2"}, "241": {"fulltext": "ME SOPH Y TES. 2$$\\neffects due to these three factors. It is difficult, if not im-\\npossible at present, to say which are the effects of light and\\nwhich of evaporation.\\nPrecipitation affects plants chiefly as it influences water\\nsupply. A few plants only of the higher forms are able to\\nabsorb moisture directly from the air, except as a last resort.\\n(See ^J 165.) Many of the lower plants, such as the algae,\\nlichens, and mosses, absorb rain instantly by their aerial\\nparts. Some plants have adapted themselves to frequent and\\nprolonged rainfall, bearing it often for months at a time\\nother plants under such conditions lose their leaves very\\nquickly. Rain-loving plants have their leaves furnished with\\nelongated tips or with grooves and hairs to carry off the rain\\nquickly. Their surfaces, also, are not readily wetted by\\nwater. Others protect themselves against the rain by adjust-\\ning the direction of their leaves to it so that a heavy, splash-\\ning rain strikes them at an acute angle. Others, by a move-\\nment of their leaves as soon as the sky is clouded, avoid\\ninjury from heavy rains. The branching of leaves in certain\\ncases may be looked upon as a protection against heavy rain-\\nfall.\\nThe snow cover through cold periods is for many plants\\nessential as a protection against low temperatures during the\\ndormant period. Others have adapted themselves to growing\\neven in the midst of snow, putting forth their leaves and\\nblossoms while still surrounded by melting snow.\\n332. 5. Soil. Both the chemical composition and the\\nphysical properties of the soil affect plants. The latter are,\\nhowever, by far the most important. Here, again, the rea-\\nson is to be found in the relation of the physical qualities of\\nsoil to the water supply.\\nThe water which permeates the soil takes up from it certain\\nsubstances, and becomes thus a dilute solution of various\\nsalts. That the salts thus present in the soil water may affect", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0241.jp2"}, "242": {"fulltext": "236 OUTLINES OF PLANT LIFE.\\nthe form of the plant is strikingly shown in the occurrence\\nof certain species of a genus only upon soils containing lime,\\nwhile others of the same genus are found only in soils free\\nfrom lime. When the local distribution of corresponding\\nspecies of the same genus within the same region is deter-\\nmined by the presence or absence of lime in the soil, com-\\nparison of them indicates the general effect of lime salts upon\\nthe plant. Plants growing upon lime are usually stronger\\nand more densely hairy, often hoary, while those on other\\nsoils are smooth or furnished with glandular hairs. The\\nlime -loving plants have bluish-green leaves, as contrasted\\nwith the grass-green. Their leaves are also more numerous\\nand more deeply branched, the flowers larger and their colors\\nduller and paler.\\n333. Summary. Mesophytes have a moderate water sup-\\nply. Arbitrarily selected as the norm, their adaptations are\\nnevertheless as numerous and important as those of other\\nplants, but less striking only because they are familiar to the\\neye. Thus they adjust themselves in form and structure to\\nthe wind, the light, temperature, moisture and rainfall, and\\nthe soil. The light influences the rate of growth and de-\\nvelopment, and especially internal structure, often inducing\\na two-sided structure, as in leaves. Changes in temperature\\ncall out protective adaptation against sudden changes, and\\na dormant period (during winter), and also affect the form\\nof plants, as do moisture of the air, rain and snow. The\\nsubstances in the soil may also modify the form of a plant.", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0242.jp2"}, "243": {"fulltext": "CHAPTER XXL\\nXEROPHYTES AND HALOPHYTES.\\n334. II. Xerophytes. The plants of dry regions blend\\nby imperceptible gradations with the mesophytes. They\\nreach their best development in desert and rocky regions.\\nSome, especially of the lower forms, grow in such situations\\nthat they must adapt themselves to become so dry at certain\\nperiods that they may be powdered. Such, for example, are\\na few algse, many lichens, mosses, and a few fernworts.\\nAdaptations in these cases must be looked for in the character\\nof the cell contents.\\nOther plants must adapt themselves to endure dry periods,\\nsuch as those occurring from day to day, or between the wet\\nand dry seasons, by retaining in their bodies sufficient water\\nto sustain life. The following are some of the chief methods\\nby which plants adapt themselves to periodic or continuous\\ndrought.\\nA. Adaptations for reducing transpiration.\\n335. i. Periodic reduction of surface exposed. The\\ndying away of an annual plant after forming its seed may be\\nlooked upon as an adaptation of this sort. Little evaporation\\noccurs from the surface of the seed, which is thus adapted to\\nwithstand prolonged dryness. Perennial plants accomplish\\nthe same results when their annual shoots die off and leave\\nonly the rhizomes, tubers, and similar parts buried in the soil.\\n237", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0243.jp2"}, "244": {"fulltext": "2 3 8\\nOUTLINES OF PLANT LIFE,\\nPerennial plants with perennial shoots may drop their leaves\\nduring the dry period and form them again upon the return\\nof the growing season. The fall of leaves in our woody vege-\\ntation is a similar adaptation to the cold season. The rolling\\nor curling of leaves is a common mode of avoiding evapora-\\ntion. It is common in grasses (fig. 197) and mosses.\\n336. 2. The constant reduc-\\ntion of exposed surface.\u00e2\u0080\u0094 This\\nmay be secured among the leaves\\nI by reducing them either in area\\nor in number or both, or by\\nmuch branching, with little\\n*p\\nFig. 197. Transverse sections of a grass leaf (Lasz agrostis). A, open; B, rolled,\\nwhen dry. The white plates are the ribs of mechanical tissue above and below a stele,\\none in each ridge the shaded areas are green tissue. The stomata are located low\\non the sides of the narrow grooves between the ridges, so that when the leaf is rolled,\\nevaporation through them is hindered. Magnified 16 diam. After Kerner.\\ngreen tissue. Plants with bristle-shaped or needle-shaped\\nleaves (figs. 63, 198), those with permanently rolled leaves\\n(permanent form similar to temporary rolling shown in\\nfig. 197), or those with scale-like leaves (fig. 71) show\\nthe various phases of such adaptations. Extreme reduction\\nof surface is secured by suppression of leaves. In this case\\nany further adaptation depends upon the stems, which must\\nalso provide for nutritive work. These may take the form\\nof leaves (see 96) or the branches may be thick, rigid,\\nand fleshy (fig. 199) j or they may be thread-like or needle-\\nshaped, as in the asparagus (fig. 67); or the stems them-\\nselves may reduce their area by becoming fleshy and cylin-\\ndrical, prismatic, or spheroidal, as in the various forms of\\nCereus and melon cactuses.\\n337. 3. Movements of parts to reduce the illumina-", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0244.jp2"}, "245": {"fulltext": "XEROPHYTES AND HALOPHYTES.\\n239\\ntion. Certain leaves are adapted to a permanent profile\\nposition, that is, with the edges turned toward the sky, in-\\nstead of the surfaces. (See 243.) Others assume a profile\\nposition when the illumination\\nbecomes too intense. These\\npositions, by placing the leaf\\nsurface oblique to the direction\\nof the light rays, reduce the\\namount of evaporation very con-\\nsiderably.\\n338. 4. Coverings, consisting\\nof living or dead scale-leaves,\\nstipules, leaf-bases or entire\\nleaves, reduce transpiration by\\nobstructing the free exchange of\\nair, or by holding water and so\\nkeeping moist the surfaces they\\ncover.\\n339. 5. Structural modifica-\\ntions. These may occur either\\nin the epidermis or some inter-\\nnal tissues. (a) The epidermis\\nmay greatly reduce evaporation\\nby the formation of hairs in such\\nprofusion as to form a cover for\\nthe surface (figs. 200-202).\\nHairs intended to protect from\\nevaporation are usually dead and\\nfilled with air. Reflecting light\\nfrom many points, they look white, and the surface seems hoary,\\nor woolly, or silky. Hairs in the form of scales which overlap\\nreduce the rate of evaporation by covering the stomata (fig.\\n203). Further adaptations of the epidermis are to be found in\\nthe water- proofing of part or all of the outer wall of the epider-\\nFiG. 198.\u00e2\u0080\u0094 Shoot of larch, with ripe\\ncone showing needle-shaped leaves\\non dwarf branches scale leaves on\\nmain axis. Natural size. Afttr\\nKerner.", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0245.jp2"}, "246": {"fulltext": "240\\nOUTLINES OF PLANT LIFE.\\nmis (ep f fig. 205) the development of two or more layers of\\nepidermal cells (fig. 208) or the excretion of wax or of\\nvarnish upon the surface of the epidermis. The latter often\\nFig. 201.\\nFig. T99.\u00e2\u0080\u0094 Prickly pear (Ofnmtia vulgaris) with flattened jointed stem and no leaves.\\nAbout one fourth natural size. After Frank.\\nFig. 200. Multicellular hairs of edelweiss. Magnified about 50 diam. After Kerner.\\nFig. 201. Silky unicellular hairs of Convolvulus Cneorum. Magnified about 50 diam.\\nAfter Kerner.\\nFig. 202.\u00e2\u0080\u0094 T-shaped hairs of Artemisia mutellina. Magnified about 50 diam.\u00e2\u0080\u0094 After\\nKerner.\\nbecomes very thick, giving to the leaves a shiny appearance.\\nWax is usually in the form of a bluish-white powder, which\\ncan be readily wiped off with the fingers, as from the surface\\nof fruits, such as plums or grapes, the leaf of cabbage, or the", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0246.jp2"}, "247": {"fulltext": "XEROPHYTES AND HALOPHYTES.\\n2 4 I\\nstalk of sugar-cane (fig. 204). The interior layers of the\\nwall of the epidermis are sometimes converted into mucilage,\\nwhich retards the evaporation of water.\\nThe sinking of the stomata below the\\ngeneral level (fig. 205), their arrangement\\nin pits (fig. 206) or in grooves (fig. 197),\\nand their restriction to the under side of\\nthe leaf (fig. 206) may-\\nbe looked upon as\\nfurther epidermal\\nadaptations to reduce\\nevaporation. In the\\nleaves of some xero-\\nphytes the guard cells\\nof the stomata are\\nonly when\\nyoung, becoming\\nthick-walled and fixed when the leaf is mature. The stoma\\nitself sometimes becomes closed, also. V) The internal\\nFig. 203. Shieldlike scales of an oleaster (Elceagnns\\nangustifolia), seen from above. Magnified about niOtile\\n50 diam. After Kerner.\\nFig 204. Fig 205.\\nFig. 204. Portion of a transverse section through a node of sugar-cane, showing rods\\nof wax secreted by the epidermis. Magnified 142 diam. After De Bary.\\nFig. 205. Transverse section of a portion of the margin of a leaf of Aloe socotrina.\\nr, thick cuticle; u, cutinized layers of wall of epidermis, ef p, green cells; cr,\\na crystal cell with needle crystals of oxalate of lime s/ guard cells of stoma,\\nsunk below surface a, intercellular space under stoma. Magnified about 175 diam.\\nAfter Tschirch.", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0247.jp2"}, "248": {"fulltext": "242\\nOUTLINES OF PLANT LIFE.\\ntissues of the leaves may be more compact. This reduces\\ntranspiration by restricting the area of the air passages.\\nFig. 206.\u00e2\u0080\u0094 Portion of a vertical section of a leaf of oleander. ef epidermis of upper\\nface e/ same of lower face with stomata, .v, in deep pits with numerous hairs, t\\npal, palisade cells in two layers s/ spongy cells h cells adapted to water stor-\\nage. Chioroplasts shown only in left-hand side of the figure. Magnified about 175\\ndiam.\u00e2\u0080\u0094 After Van Tieghem.\\nB. Adaptations for taking up water.\\n340. Absorption. i. Some plants are adapted to imme-\\ndiate absorption of moisture in the air or of liquid water\\nfalling on their aerial parts. Such are, usually, the algae,\\nlichens, and mosses which grow in exposed situations. 2.\\nCertain of the higher plants are furnished with hairs adapted\\nto the prompt absorption of rain or dew, e.g., Spanish moss.", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0248.jp2"}, "249": {"fulltext": "XEROPHYTES AND HALOPHYTES. 243\\n3. Other plants adapt aerial roots to the absorption of\\nmoisture from the air, as well as falling water. (See 165.)\\n4. Many are surrounded by the bases of dead leaves, which\\nact as a sponge for absorbing water, and supply it gradually\\nto the stem or younger leaves. Living leaves, sometimes\\nsingly, sometimes in clusters, form cuplike or tubular\\nstructures, acting as water receptacles, from which it can be\\nabsorbed as required. Such adaptations occur chiefly in\\nepiphytes. (See 357.) 5. Many xerophytes develop\\nexceedingly long tap roots, which penetrate the soil deeply\\nto a permanent water supply.\\nC. Adaptations for storing water.\\n341. 1. Special cell contents. The simplest of these\\nadaptations is the presence of mucilage. The presence of\\nacids, tannins, and certain salts perhaps aids in the retention\\nof water.\\n342. 2. Water-storing tissues. (a) Fleshy plants, or\\nsucculents, are those which thicken their parts by the devel-\\nopment of cells, which contain a large quantity of water, and\\nusually much mucilage.\\nThese mucilage-con-\\ntaining parts form a\\nreservoir for the storing\\nof water. In such\\nplants the epidermis is\\nvery strongly water-\\nproofed the stems are\\nthick, cylindrical, pris- T\\nJ tig. 207. \u00e2\u0080\u0094A plant of houseleek (Semperznv7t)n\\nmatic Or Spheroidal tectorum), showing fleshy leaves arranged in a\\n1 rosette, with offsets formed at the ends of special\\nthe leaves are Wanting branches. These become detached and form in-\\ndependent plants. About one half natural size.\\nor they are thick and After Gray.\\nfleshy, cylindrical or broad (fig. 207), and arranged in\\nrosettes.", "height": "3581", "width": "2260", "jp2-path": "outlinesofplantl00barn_0249.jp2"}, "250": {"fulltext": "244\\nOUTLINES OF PLANT LITE.\\n(3) In non-succulents, the epidermis itself may be greatly\\ndeveloped as a water-storing tissue, or it may form great num-\\nbers of bladdery hairs which\\nare richly supplied with\\nwater, as in the well-known\\nice-plant, on which the\\nhairs glisten like ice.\\nIn the first case, the epi-\\ndermis, instead of forming a\\nsingle layer of cells, may\\ndevelop into several layers,\\nthe lower ones large and\\nthin-walled, as in begonias,\\nfigs, and peppers (fig. 208).\\nThe cells immediately under\\nthe epidermis sometimes\\nbecome transformed into a\\nwater-storing tissue, as in\\nthe oleanders (fig. 206) or\\nstrips of tissue extending\\nfrom the upper to the lower\\nside of the leaf may act as\\nreservoirs of water.\\n343. 3. Tubers and bulbs.\\nThese forms of the shoot,\\nFig. 208. Strip from a vertical section of t^i v A\\nleaf of Peperomia trichocarpa. J, from which are HCMy Supplied\\na fresh leaf; w. water-storing tissue, com-\\nposed of the multiple epidermis of the upper With Water, may alSO De\\nside a, chlorophyll-bearing cells; s, spongy\\nparenchyma with sparse chloroplasts and COUnted, in part at least, aS\\nmuch water. B, the same after four days r\\ntranspiration at 18-20 C. The tissue to is ail adaptation IOr Water-\\nmuch collapsed, the walls being plaited\\nj also shrunken, but a as before. Magnified Storage,\\nabout 50 diam. After Haberlandt. _ __ T TT\\n344. III. Halopnytes.\\nThe salt-loving plants, though they may grow where water\\nis abundant, are strikingly similar in most of their characters\\nto the xerophytes. This similarity is to be explained prob-", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0250.jp2"}, "251": {"fulltext": "XEROPHYTES AND HALOPHYTES. 2\\\\%\\nably by the difficulty of securing a suitable water supply.\\nThey grow near the ocean, upon the shores of salt lakes, by\\nsalt springs, and in the interior of the great continents in old\\nlake basins in which the salts have accumulated by the rains.\\nA few of the halophytes are trees and shrubs, with leathery\\nleaves, but almost all are succulents. In habit they are gener-\\nally low, often creeping, with thick, fleshy, and more or less\\ntranslucent leaves and stems, containing comparatively little\\nchlorophyll and abundantly supplied with water, and the\\nsurface generally smooth.\\n345. Summary. Drought plants adapt themselves to a\\nscanty supply of water by (a) reducing the transpiration, [b)\\nproviding means of securing water, or (c) by storing water.\\nReduction of transpiration may be secured by periodic or\\npermanent reduction of evaporating surface, by avoiding di-\\nrect light, by water-proof or wax-covered skin, by mucilage in\\nthe cells or by obstructing the stomata with coverings of\\nscales or hairs. Adaptations for securing water are special\\nabsorbing organs on aerial parts, cuplike parts for holding\\nwater, and long roots to reach deep soil w r ater. Adaptations\\nfor water-storage are water-holding substances in the cells,\\ncell specialized as water reservoirs, and thickened shoots such\\nas tubers and bulbs.\\nSalt plants are mostly succulents, and show adaptations\\nsimilar to the drought plants.", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0251.jp2"}, "252": {"fulltext": "CHAPTER XXII.\\nHYDROPHYTES,\\n346. IV. Hydrophytes may be divided into three groups\\ni. Slime plants, which grow in the mud or slime at the bot-\\ntom of bodies of water. Here belong many algae, especially\\ndiatoms, many species of low fungi, and -bacteria in great\\nnumbers. 2. Submersed plants, either free or attached.\\nMany algae, including both the diatoms and the filamentous\\nalgae, are found floating in the water at various heights,\\nsometimes near the surface, sometimes more deeply submersed.\\nSince their substance is heavier than water, their capacity to\\nsustain themselves depends upon the production of gases in\\nthe interior of the cells, or upon the presence of gases en-\\ntangled among their filaments. A few of the higher plants\\nare also found submerged and free, such as the bladder-worts.\\nThe number of free-floating plants of the larger kinds is\\nsmall compared with those attached. The higher algae,\\nmoss-worts, fern-worts, and seed plants are usually fastened\\nin the mud or to sticks and stones. The thallus of the algae\\nis usually profoundly branched and the shoots of the mosses\\nare richly supplied with leaves. All of the submerged fern-\\nworts and seed plants are characterized by a very delicate\\nepidermis, the absence of stomata, and the extensive surface\\ndue to the very profuse branching of the stems or leaves, or\\nto the great number of these, or to both. In all cases the\\nextensive green surface may be looked upon as an adaptation\\nto securing carbon dioxid and the manufacture of sufficient\\nfood by means of the weak light in a situation where there is\\n246", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0252.jp2"}, "253": {"fulltext": "HYDROPHYTES. 247\\nno danger from lack of water. 3. Floating or partly sub-\\nmersed plants, either free or attached. Many of the filamen-\\ntous algae and diatoms float free at the surface. The chief\\ncharacteristics of the higher floating plants which root in the\\nmud are these their floating leaves are simple, little branched\\nor not at all, roundish or elliptical in form, leathery, and the\\nsurface not easily wetted; stomata are present only on the\\nupper surface, and the leaf stalks are adapted in length to\\nthe depth of the water in which they grow the woody\\ntissues are either entirely absent or poorly developed, be-\\ncause there is no occasion for the transportation of water,\\nnor need of rigidity, since the medium in which they grow\\nsupports most of the w r eight.\\n347. Light. Green water plants are limited in their\\ndistribution by the depth to which light can penetrate water.\\nThis does not exceed, even in pure waters, four or five hun-\\ndred meters. No seed plants have been found at a greater\\ndepth than thirty meters, and few algae at a greater depth\\nthan forty meters. Plants which are brought up by dredging\\nfrom lower depths than this are usually those which have been\\ndetached and sunk.\\n348. The temperature of the water is very much less sub-\\nject to variation than that of the air, never falling, except at\\nthe surface, below 0.5 C.\\n349. The movements of the water are of much importance\\nto plants in bringing air and food materials to them. These\\nmovements are wave movements, or surf, and currents.\\nPlants growing within the limits of wave action are often\\ndamaged or torn away by the waves. The Sargasso Sea is\\nmarked by an accumulation of such plants, mainly of brown\\nalgae, which have been swept to the quieter parts of the North\\nAtlantic by currents after having been detached by the waves.\\nSuch plants may often live for a long time and may even\\ncontinue their development.", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0253.jp2"}, "254": {"fulltext": "248 OUTLINES OF PLANT LLFE.\\nPlants adapt themselves to currents, such as those in fresh-\\nwater streams, by their slender form, which is characteristic\\nof plants in flowing waters, as seen in filamentous algae and\\nthe much-divided leaves of higher plants. Currents of water\\nact as a stimulus upon certain plants, producing a direct re-\\naction in the mode of growth.\\n350. The composition of the water affects chiefly the dis-\\ntribution of plants, in a manner similar to the presence of\\nsalts in the soil. In the ocean waters the percentage of salts\\nis extremely variable in different regions in some places it\\nis as low as 0.5 per cent., while in others it reaches 4 per\\ncent. In fresh waters the differences in kind and amount of\\ndissolved salts are chiefly due to differences in the soils which\\nthe streams drain.\\n351. Summary. Water plants may grow in the mud or\\nslime at the bottom submersed, and either free or attached;\\nor floating and either free or attached. The light, temperature,\\nmovements of the water and the composition of the water are\\nthe principal factors to which water plants must adapt them-\\nselves.", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0254.jp2"}, "255": {"fulltext": "II. ADAPTATIONS TO OTHER PLANTS.\\n352. Plant associations. Each set of external conditions\\nbrings about the association of certain plants with one another,\\nbecause they have adapted themselves to those conditions.\\nThe four groups just considered may be looked upon as plant\\nsocieties of the most general kind. Within each of these\\nfour it is possible to distinguish a number of smaller societies\\ndetermined by a more limited range of conditions.\\nBesides these plant associations, however, there are those\\nwhich are determined by the relation of the plants to one\\nanother, as affording mechanical support, or assistance in the\\nwork of nutrition. The plant associations of this kind only\\nare now to be considered.\\nCHAPTER XXIII.\\nADAPTATIONS TO OTHER PLANTS AS SUPPORTS.\\nCertain plants serve others as carriers, acting purely as\\nmechanical supports. To these supports plants have adapted\\nthemselves in various ways. In many instances dead objects\\nof similar form may serve the same purpose. The supported\\nplants are, therefore, partly independent of the others, though\\nin most instances in nature they rely upon living supports.\\n353. i. Climbing plants. Climbing plants are those that\\ndevelop lateral organs, sensitive to contact, which become\\nrecurved or coil about a support of suitable shape and size, or\\nform adhesive disks by means of which they cling to rough\\n249", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0255.jp2"}, "256": {"fulltext": "25O OUTLINES OF PLANT LIFE.\\nsurfaces. These lateral organs take the place of leaves or of\\nlateral shoots, and are known as tendrils (figs. 69, 102).\\n(For their form see 99, 131; for their action, 1 225, 251).\\n354. 2. Clambering plants are those which form lateral\\norgans not sensitive to contact, and by means of them sup-\\nport themselves on adjacent plants. Recurved leaves, shoots,\\nand prickles (fig. 99) may serve these purposes.\\n355. 3. Twining plants are those which have adapted their\\nshoots to winding about a support of suitable size. (See\\n249.)\\n356. 4. Root climbers have adapted their aerial roots to\\nattaching the plant to rough surfaces. (See 82.) Such\\nstructures are found only in fernworts and seed plants.\\n357. 5. Epiphytes. This name is rather loosely applied\\nto those plants which are attached only to other plants, though\\nthey derive no food from them. All kinds of plants have\\nrepresentatives in this group. Algae, diatoms, and other\\nsmall water plants attach themselves to other algae and the\\nhigher water plants. Lichens, liverworts, mosses, ferns,\\norchids, bromelias, etc., are abundant upon trees. Epiphytes\\nare attached by hairdike rhizoids, or by hold-fasts, which\\napply themselves to the roughnesses or even penetrate the\\nouter dead parts of the supporting plant, but do not absorb\\nfrom the living tissues either water or food materials. The\\nwater supply is provided for (1) by adaptations for absorbing\\nrain or dew, mists, or even dampness, instantly, either by the\\nsurface, as in algse, mosses, and lichens, or by means of hairs,\\nas in the Spanish moss and other seed plants (2) by adap-\\ntations to catch the water in living or dead leaves and hold\\nit, either by capillarity or as a vessel, long after precipitation\\nhas ceased. Many of the simpler epiphytes are adapted to\\nbecome dry without injury, while the larger ones are inhabit-\\nants of moist tropical regions, where the danger of drying is\\navoided and it is possible to obtain an adequate water supply.", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0256.jp2"}, "257": {"fulltext": "PLANTS AS MECHANICAL SUPPORTS. 25 1\\nTheir food materials are derived entirely from the air and the\\nwater which falls upon them, while the mineral salts are ob-\\ntained from the dust which has been carried by the air and\\naccumulated upon the surface of the supporting plant, or\\namong the mass of dead and decaying leaves and other de-\\nbris about the base of the epiphyte. Organic matter from\\nthe decay of the older parts may also be reabsorbed.\\nAn adaptation to this mode of life is marked in the repro-\\nductive bodies. Of all epiphytes the seeds or spores are either\\nlight and carried by the wind or the seeds are sticky and\\ncarried by birds and other animals or they are eaten by\\nbirds and voided upon the trees where they are adapted to\\ngerminate.\\n358. Purpose. In most cases, the use of other plants as\\nsupports has been adopted to secure for the smaller and\\nweaker plants proper exposure to light for making food.\\nFor example, so dense are the tropical forests that only by\\nclimbing to the tree-tops or perching on the branches can the\\nlowlier plants secure an adequate amount of light. Even in\\nthe temperate zone the advantage in climbing for light is\\nobvious.\\n359. Summary. Plants rooted in the soil adapt them-\\nselves to use others as mechanical supports by the develop-\\nment of tendrils or aerial roots for climbing recurved leaves,\\nshoots, or prickles for clambering and long, swinging sensi-\\ntive shoots for twining. Others use their neighbors as the sole\\nsupport, being perched upon them but deriving no food from\\nthem. (Those which do absorb food are parasites. See\\n184). In most cases the purpose of such adaptations is to\\nsecure light.", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0257.jp2"}, "258": {"fulltext": "CHAPTER XXIV.\\nSYMBIOSIS.\\n360. Living contact. Not only are different species as-\\nsociated through the influence of similar surroundings which\\nthey find congenial, but certain plants adapt themselves to\\nsuch an intimate relation with others that they live in imme-\\ndiate contact with them. This intimate association is known\\nas symbiosis. When the parties to symbiosis stand to each\\nother in the relation of partners, each furnishing certain\\nmaterials or conditions advantageous to the other, the asso-\\nciation is called mutualistic symbiosis or mutualism. When the\\nrelation of the parties is that of master and slave, one indi-\\nvidual deriving advantage from the labor of the other and in\\nreturn furnishing it suitable conditions for existence, the\\nassociation is a form of mutualism known as helotism. Finally,\\nwhen the relation of the parties is that of an unwilling host\\nand an unwelcome guest, one individual being fastened upon\\nby the other from whose presence it is unable to free itself,\\nthe symbiosis is called parasitism. (See ^[^j 44, 45, 46,\\n184.)\\nA. Mutualism.\\n361. 1. Between plants of the same species. Mutualism\\nmay occur between individuals of the same species. Illus-\\ntrations of this are to be seen in the massing of the lower\\nalgae into colonies, in some of which certain individuals may\\nbe differentiated from others for the purpose of carrying on\\n252", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0258.jp2"}, "259": {"fulltext": "SYMBIOSIS. 253\\na function of advantage to the colony. (See \u00e2\u0080\u00a2^j 10, 11,\\n17.) In a somewhat similar way certain bacteria are found\\nalways massed into colonies of characteristic outline, of\\nwhich one form is shown in fig. 209. In the higher fungi,\\na\\nA B\\nFig 209. A, worm like colonies of Chontlrowyces serpens, composed of numerous\\nrod-shaped individuals, a, which multiply by fission, and secrete a mass of jelly\\nwhich holds them together. A, magnified 45 diam. B, 750 diam. After Thaxter.\\nalso, the mycelium may be looked upon as a thallus formed\\nby the aggregation of many individuals for, while it is pos-\\nsible to have mycelium produced from the development of a\\nsingle spore, it is not common. The mycelium is generally\\nthe result of the union of hyphae (see 43) arising from\\nmany spores. Even in such cases the mycelium may con-\\nstitute a single body, and may give rise to a single fructifica-\\ntion.\\n362. 2. Between plants of different species. Mutualism\\nis more common between plants of different species. It\\ntakes the following forms\\n363. (a) Lodgers. The higher plants often shelter vari-\\nous species of lower ones within their internal chambers, or\\nin pockets formed by lobes or bladders of various sorts.\\nThis relation is especially common between water plants and\\nalgae. Species of Nostoc live in the air spaces of liverworts\\nand duckweeds, in the roots of some land plants, and in the\\nleaf-lobes of liverworts. Some species of the higher algae,\\nalso, are frequently associated with other species to which\\nthey attach themselves. That they are not merely epiphytes\\n(see 1] 357) is shown by the fact that certain algae are found\\nonly upon certain other kinds, and do not grow indifferently", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0259.jp2"}, "260": {"fulltext": "254\\nOUTLINES OF PLANT LIFE.\\nupon any plant which would furnish them similar external\\nconditions (fig. 210).\\n364. (b) Mycorhiza. Mutualism between the roots of the\\nseed plants and certain fungi is common. Such a combina-\\ntion of root and fungus is called a mycorhiza. The fungus\\nFig. 210. Fig. zix. Fig. 212.\\nFig. 210. A portion of a filament of an alga {Ectocarftus) showing at a another alga\\n(Entoderma Wittrockii) which has embedded itself in the cell-wall. Magnified 480\\ndiam.\u00e2\u0080\u0094 After Wille.\\nFig. 211. A tuft of rootlets of white poplar forming mycorhiza. Natural size.\\nAfter Kerner.\\nFig. 212. Tip of a rootlet of beech (Eagus sylvatica) with fungus mantle, the loose\\nhyphae acting as absorbing organs in place of root hairs. Magnified 100 diam. After\\nFrank.\\nforms a jacket over the outside of the root (figs. 211, 212),\\ntaking the place and work of the root hairs by means of\\nstrands of hyphae extending from the surface of the fungus\\njacket (fig. 212) or it grows inside the cortex and epider-\\nmis, forming knotted masses (fig. 213) or it is confined to\\ncertain definite portions of the roots, forming upon them\\nswellings from the size of a hazelnut to the size of a man s\\nhead. The first form is especially common upon the roots\\nof the oak, elm, walnut, apple, pear, maple, ash, and related\\ntrees. It has also been found upon the roots of a large num-\\nber of herbaceous plants. The second form belongs chiefly", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0260.jp2"}, "261": {"fulltext": "SYMBIOSIS.\\n255\\nto the heaths and orchids. The third form grows upon\\nalders, bayberry, etc.\\n365. (c) Root tubercles of Leguminosae. A peculiar case\\nof mutualism appears in the bean family between the roots\\nand bacteria. The latter produce\\nupon the roots small swellings from\\nthe size of a grain of wheat to that\\nof a hazelnut (fig. 214). The\\npresence of these bacteria, in a\\nway yet unexplained, certainly en-\\nables the plant to use free nitrogen\\nfrom the atmosphere, while other\\nplants are required to obtain it\\nfrom the soil in combination with\\nother things. The enrichment of\\nthe soil by growing clover and\\nsimilar crops upon it and plowing\\nthem under is explained by their\\nability thus to accumulate nitrogen\\nfrom the air.\\n366. 3. Between plants and\\nanimals. Mutualism also occurs\\nbetween plants and animals.\\nVarious species of plants attach\\nthemselves to animals by which\\nthey are carried about. The plant\\nis thus aided in obtaining the ma-\\nterials for food, and not infrequently the plant conceals the\\nanimal from another which seeks it as prey. In this way\\ncertain crabs are hidden by algae attached to them.\\nFig. 213. Mycorhiza of orchids.\\nA bit of longitudinal section of\\nroot of Neottia, near the tip. e,\\nepidermis p. a series of cortical\\ncells filled with fungus. Into the\\ncell a (nearer the tip of root) the\\nhyphae are just entering; in the\\ncells above, i, recently entered,\\nthey have only formed a small\\nknot about the nucleus. Magni-\\nfied about 200 diam. After\\nFrank.\\nB. Helotism.\\n367. 1. Fungi and algae. Helotism exists between fungi\\nand algae, constituting the bodies known as lichens, in which", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0261.jp2"}, "262": {"fulltext": "256\\nOUTLINES OF PLANT LIFE.\\nthe fungus is the master and the alga the slave. (See 1 48,\\nand figs. 215, 216.) The same fungus may be found en-\\nslaving more than one species of alga? even within the same\\nmycelium. The proto-\\nnema of mosses (see\\n59) or even the leaves of\\nsome small plants may\\nbe surrounded by a my-\\ncelium. The enslaved\\ngreen plants are generally\\nunicellular or filamentous\\nalgae. If the latter are\\nthe species whose colonies\\nproduce voluminous gela-\\ntin, the texture of the\\nlichen body is gelatinous\\notherwise it is tough and\\nleathery. Some of the\\nfungi which ordinarily\\nassociate themselves with\\nalgae to form lichens may\\nexist free as saprophytes.\\nThe alga itself influences\\nthe form of the thallus more or less profoundly according\\nto its relative amount. The same fungus associated with\\ndifferent algae produces lichens which are described as differ-\\nent species, or even as different genera.\\n368. 2. Animals and algae. Helotism exists between\\nanimals and algae. Various simple animals, such as radio-\\nlaria, stentors, hydras, sponges, echinoderms, and worms,\\nenclose algae in their bodies and utilize the products of their\\nfood manufacture. The algae thus enslaved are all minute\\nunicellular forms which multiply within the animal body by\\nfission 260).\\nFig. 214. A young clover plant, showing tuber-\\ncles, t, on the roots. Natural size. After\\nGoff.", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0262.jp2"}, "263": {"fulltext": "S Y MB 10 SIS.\\n257\\nC. Parasitism.\\n369. 1. Fungi. A very large number of colorless plants\\nhave adapted themselves to live upon living plants or ani-\\nmals which they\\nforce to act as their\\nunwilling hosts. By\\nthe presence of the\\nparasite the normal\\nfunctions of the host\\nor its normal growth\\nor both are more or\\nless seriously inter-\\nfered with, so as to\\nproduce disease,\\nslight or grave, local\\nor general, accord-\\ning to the circum-\\nstances. Many ani-\\nmals are thus preyed\\nupon by\\nand fungi,\\nFig. 215. A lichen {Parmelia conspersa) growing on\\na stone, showing the leaf-like thallus (mycelium), with\\nmany cup-like fructifications. Natural size. After\\nFrank.\\nbacteria\\nMost communicable diseases, such as typhoid\\nfever, diphtheria, and tuberculosis, are\\nknown to be due to the transfer of the\\nparasite from the diseased individual to the\\nhealthy one. In a similar way bacteria live\\nas parasites upon green plants, causing\\ndisease and often death. The number of\\nfig. 216 -Hyphae of bacterial diseases among plants is relatively\\na lichen, Cladotaa\\nfurcata (see fig. 36), small, for comparatively few bacteria have\\nenveloping an alga,\\nProtococcus. Mag- been able to adapt themselves to living in\\nnined 950 diam. x\\nAfter Kemer. the acid cell sap of plants. The number of\\ndiseases of plants due to parasitic fungi, on the contrary,", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0263.jp2"}, "264": {"fulltext": "258\\nOUTLINES OF PLANT LIFE.\\nis very large. (For the mode by which parasitic fungi gain\\nentrance to the bodies of their hosts, see ^[45.)\\nG\\nFig. 217.\u00e2\u0080\u0094 Roots of a yellow Gerardia, G, attached to the root of a blueberry bush, B.\\nThey enlarge at the points of contact and there send haustoria into the host root.\\nNatural size.\u00e2\u0080\u0094 After Gray.\\n370. 2. Seed plants. A few seed plants have adapted\\nthemselves to a parasitic life upon others. Some may be\\nFig. 28. A, European dodder twining about a hop stem. All but the uppermost coils\\nshow the groups of wartlike swellings from which haustoria penetrate the host stem.\\nNatural size. B, Germination of same. The various stages are arranged in order\\nfrom right to left. In the last stage the seedling has found a suitable support and has\\nabsorbed all the reserve food in the thickened lower end, which has withered and died,\\nfreeing the plant from the ground. Magnified about 2 diam. After Kerner.", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0264.jp2"}, "265": {"fulltext": "SYMBIOSIS.\\n259\\nreckoned as semi-parasitic, having still green leaves and true\\nroots. In addition, however, special organs are developed\\nfor attaching the parasite to the roots of other plants, from\\nwhich at least a water supply and probably food materials\\nare absorbed (fig. 217). Other semi-parasites, such as the\\nmistletoe, attach themselves to the host above ground, and\\nhave no true roots of their own. Some parasitic seed plants\\ntwine about their hosts, and send\\ninto them absorbing organs by means\\nof which they derive all their food\\nfrom the host. Such is the yellow\\nparasitic vine known as dodder (fig.\\n218, A). These plants germinate\\nin the ground, and as seedlings\\npossess true roots, but after attaching\\nthemselves to the host the lower part\\nof the stem dies away so that the\\ntrue roots are transient (fig. 218, B).\\nSome parasites have the body so\\nreduced that it merely forms a net-\\nwork or a hollow cylinder outside\\nthe wood of the host and under the\\nbark. From this curious body the\\nfew flowers break through the bark\\nand appear upon the surface of the\\nroot or stem of the host, quite as though they were a part of\\nit (fig. 219).\\n371. Summary. Plants may live in such relations that\\none is directly dependent upon the other for its food supply,\\nor they are mutually dependent for food or advantageous\\nconditions. Animals may likewise be directly dependent on\\nplants associated with them. Mutual dependence may exist\\nbetween plants of the same species, but is commoner between\\nplants of different kinds. One kind may lodge in cavities or\\nFig. 219. A twig infested with\\na parasitic seed plant {Afiodan-\\nthes) whose body is hidden\\nunder the bark of the host,\\nthrough which a short branch\\nbearing a few scale leaves and\\na single flower bursts. Natural\\nsize.\u00e2\u0080\u0094 After Kerner.", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0265.jp2"}, "266": {"fulltext": "260 OUTLINES OF PLANT LIFE.\\ninternal chambers in the other. Fungus filaments associate\\nthemselves with roots, particularly of trees. Bacteria, in con-\\nnection with roots of the bean family, enable them to acquire\\nnitrogen from the air, as other plants cannot. Fungi and\\nalgae, in the relation of master and slave, form the lichens.\\nAlgae are similarly enslaved by a few animals. A great\\nnumber of fungi and bacteria attack other plants and also\\nanimals, causing more or less extensive deformity and dis-\\nease. Only a few seed-plants live as parasites upon others.", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0266.jp2"}, "267": {"fulltext": "III. ADAPTATIONS TO ANIMALS.\\nCHAPTER XXV.\\nANIMALS AS FOOD, FOES, OR FRIENDS.\\n1. Carnivorous plants.\\n372. Nitrogen supply. The ordinary source from which\\ngreen plants obtain nitrogen for the making of their food is\\nthe nitrogen compounds dissolved in the soil water. Plants\\nwhich live where the soil water contains little or no nitroge-\\nnous material are forced to resort to another source of supply.\\nSome plants solve the problem by entrapping animals, deriv-\\ning from their bodies the desired nitrogen compounds. Such\\nplants are called carnivorous plants, or, since the bulk of\\ntheir catch consists of insects, insectivorous plants. The\\ncatching of animals is done\\n373. i. By pitfalls and traps. (a) The various pitcher\\nplants furnish a fine example of well-devised pitfalls. The\\nleaves of these plants have a deep, trumpetlike tube making\\nup the body of the leaf; or they carry at the end of a long\\npetiole a deep cup with a lid, as in the tropical pitcher plants\\n(fig. 220; see also fig. ioi). The tube is one-third or half\\nfull of water, in which are always found numbers of dead or\\ndying insects. The sides of the tube without are often made\\nattractive by gaudy colors or by lines of sweet secretion,\\nwhich draw both flying and crawling insects. Within, its\\nsurfaces are either excessively smooth, so as to afford no foot-\\n261", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0267.jp2"}, "268": {"fulltext": "262\\nOUTLINES OF PLANT LIFE.\\nhold to an insect attempting to crawl out or covered by-\\nstiff, downward-pointing hairs to oppose its passage or the\\nside of the tube is filled with thin translucent spots through\\nwhich the captives vainly strive to fly, while the real opening\\nis concealed. By one or\\nother of these means the\\nprey is prevented from\\nescaping, and sooner or\\nlater is drowned in the\\nliquid. In this liquid di-\\ngestive substances or bac-\\nteria quickly dissolve the\\nsofter parts of the insect\\nbodies, and the soluble\\nportions are absorbed by\\nthe leaf.\\n(5) The bladderwort,\\nwhich abounds in quiet\\npools, furnishes an excel-\\nlent illustration of traps\\n(figs. 221, 222). Upon\\nthe leaves are numerous\\nminute bladders, each with\\na small opening about\\nFig. 220.\u00e2\u0080\u0094 .4 trumpet-shaped sessile leaf of Sar- which divergent hairs Serve\\nracenia variolaris, showing thin membran-\\nous windows in the meshes of the veins of the as guides to the entrance.\\nhood which arches over the mouth of the\\ntrumpet. B, cup-shaped petioled leaf of Ne- The entrance is lightly\\npenthes villosa, with elevated lid and margin\\nribbed. One-third natural size.\u00e2\u0080\u0094 After Kerner. closed by a flap of mem-\\nbrane, which is readily lifted by minute water animals.\\nAfter they have passed through the opening the membrane\\ndrops behind them, and is stiff enough to prevent their\\nescape. Death ensues sooner or later, and absorbing hairs\\non the inner face of the trap take up the nutritive ma-\\nterials.", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0268.jp2"}, "269": {"fulltext": "ANIMALS AS FOOD, FOES, OK FFJENDS.\\n263\\n374. 2. By adhesive surfaces. Animals are also cap-\\ntured by adhesive surfaces. These surfaces are covered by a\\nFig. 22t. A bladderwort iUtricularia Grafiana), showing an aerial flower stalk\\ncarrying an open flower and a second one above from which the corolla has fallen.\\nSome stems bear numerous, finely branched leaves, b, and others the large bladders,\\nb See fig. 222. A shoot of a smaller species is shown at ft, with bladders and\\nleaves on same stem. About two-thirds natural size.\u00e2\u0080\u0094 After Kerner.\\nsticky fluid secreted by numerous glandular hairs, and upon\\nthese many small insects may be found dead. In many", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0269.jp2"}, "270": {"fulltext": "264\\nOUTLINES OF PLANT LIFE.\\ncases the softer parts of the insect bodies are digested and\\nabsorbed. It should be noted, however, that adhesive sur-\\nFig. 222. B Fig. 223. A\\nFig. 222. A bladder of Utricularia vulgaris, halved lengthwise, with an imprisoned\\ncrustacean, Cyclops, a to b, opening, with hairs, about it; b to c, cushion-like\\nrim, b-c part cut through, d-e surface on which the flap, rests, opening inwards\\nonly g, wall of bladder set with absorbing hairs within and glandular hairs without\\nk, the stalk (secondary petiole). Magnified 20 diam. After Cohn.\\nFig. 223. Two leaves of sun-dew (Drosera rotundi/olio). A, in expanded position\\nshowing the tentacles B, shortly after the capture of an insect. The tentacles on the\\nright half are inflexed to bring the glandular tips in contact with the prey. Magnified\\n2| diam.\u00e2\u0080\u0094 After Kerner.\\nfaces are also merely protective against the visits of unwel-\\ncome guests, who steal nectar or pollen. (See ^f 394.)\\n375. 3. By move-\\nments of traps and\\nadhesive surfaces.\\nSomewhat more com-\\nplex methods of cap-\\nture are exhibited by\\nleaves which have\\nspecial movements\\nconnected with traps\\nor sticky surfaces.\\nFig. 224. Cluster of leaves at the base of flower-stalk\\nof Venus fly-trap {Dioncea muscipula). One-half The SUndeW Of Olir\\nnatural size. After Drude.\\nswamps has the edges\\nand surface of the leaves covered with many outgrowths,\\n\u00e2\u0096\u00a0-35V", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0270.jp2"}, "271": {"fulltext": "ANIMALS AS FOOD, FOES, OR FRIENDS.\\n265\\neach of which is tipped by a large gland (fig. 223). The\\nclear, glistening fluid, a large drop of which is secreted by-\\neach gland, is sticky enough to\\nentangle even insects of consider-\\nable size, which alight upon the\\nleaves. The viscid secretion\\nenvelops the struggling insect,\\nand at the same time the branches\\nJf_ of the leaves bend slowly inward\\nuntil more and more of the sticky\\nglands are thrust upon it. The\\ncharacter of the secretion then\\nchanges. It becomes\\nmore watery and con-\\ntains substances which\\nsoon digest the softer\\nparts of the body.\\nFig. 225. P ig 226.\\nFig. 225. A, blooming plant of Aldrovandia vesiculosa. Natural size. After\\nDrude. B, a single circle of leaves seen from the center above, showing stalk and\\ntwo semicircular lobes. Magnified diam.\u00e2\u0080\u0094 After Caspary.\\nFig. 226. Transverse section through closed trap of Aldrovandia, showing on inner\\nface long sensitive hairs and many absorption hairs. Only the central part is three\\nlayers of cells thick a broad margin is only one cell thick. Compare appearance in\\nfig. 225. Magnified 20 diam.\u00e2\u0080\u0094 After Caspary.\\nThese are absorbed, and play an important part in the nu-\\ntrition of the plant.\\nDioncea (fig. 224) and its water mate, Aldrovandia (fig.\\n225), have leaves whose blades are somewhat like a spring\\ntrap. The blade is two-lobed, with a hinge along the middle", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0271.jp2"}, "272": {"fulltext": "266 OUTLINES OF PLANT LIFE.\\n(figs. 137, 226). The hinge is in reality a cushion of tissue\\nupon the back, which quickly throws the two halves of the\\nleaf together when the sensitive hairs on the inner face of\\nthe trap are touched. The movement is sudden enough in\\nDioncea to catch the slow-flying insect, or, in Androvandia,\\nthe minute water animal. The prey is prevented from escap-\\ning by the interlocking, tooth-like lobes along the edges of\\nthe leaf. Digestion and absorption of the foods follow.*\\nII. Herbivorous animals.\\n376. Protection. While a really insignificant number of\\nminute animals are eaten by plants, a very large number of\\nplants find it necessary to protect themselves in some way\\nagainst destruction by browsing animals, insects, snails, and\\nslugs. Since the animal world relies for its food supply\\nultimately upon the green plants, it is plain that no such\\nprotective measures are completely effective. The protec-\\ntion, therefore, may be looked upon as a protection against\\nextermination rather than against injury. As protective\\nadaptations against browsing animals are usually reckoned\\n377. 1. Armor, in the form of hard, leathery, sharp-\\nedged, woolly, bristly, or sticky parts, especially leaves\\n(figs. 200, 201, 202, 227); or thorns (figs. 103, 228), prickles,\\nor stinging hairs (fig. 229).\\n378. 2. Distasteful or injurious substances, such as\\nvolatile oils, camphors, acids tannins, alkaloids, etc. The\\nTravesties upon these strange methods of nutrition appear periodic-\\nally in newspapers, and plants of remarkable size and forbidding aspect\\nare represented as capturing birds, animals, and even men, that ven-\\nture into their neighborhood. It should be noted, therefore, that in all\\ncases the plants which capture animal food entrap only the smaller ani-\\nmals, scarcely any of them, except those caught by the pitcher plants,\\nlarger than the common house-fly.", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0272.jp2"}, "273": {"fulltext": "ANIMALS AS FOOD, FOES, OR FRIENDS.\\n267\\nmilky juice of plants like milkweeds, which often contains\\nacrid substances, may also be protective.\\n379. 3. Mimicry. Certain plants c\\nwhich are not distasteful or disagreeable\\nhave adopted the same form of leaves\\nand stem and the general habit of those\\nwhich grazing animals have found dis-\\ntasteful. This mimicry causes them\\nto be avoided, as well as the really\\nhurtful ones which they imitate.\\n380. 4. Ants.\u00e2\u0080\u0094 In the\\ntropics particularly, cer-\\ntain plants secure them-\\nM\\nFig. 227. Fig. 228. Fig. 229.\\nFig. 227. Edge of a leaf of a sedge {Carex stricta), showing alternate epidermal cells\\npointed and underlaid by two layers of mechanical cells. Magnified 200 diam.- -After\\nKerner.\\nFig. 228. Part of a shoot of barberry in spring showing leaves of preceding year as\\npersistent three-pointed thorns, in whose axils the buds are developing into the sea-\\nson s shoots. Natural size. After Kerner.\\nFig. 229. A stinging hair of the nettle {Urtica), in longitudinal section, x, emerg-\\nence in which the single-celled hair nbc is sunk below ab. The knoblike apex c is\\neasily broken off because the cell wall just below it is thin and brittle. The oblique\\ncutting edge left pierces the skin like a hypodermic needle and some of the acrid cell\\ncontents enters the wound, causing intense itching. Magnified 60 diam.\u00e2\u0080\u0094 After\\nFrank.\\nselves from the attacks both of browsing animals and leaf-\\ncutting insects by encouraging the presence of colonies\\nof warlike ants upon them, and making provision for", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0273.jp2"}, "274": {"fulltext": "268\\nOUTLINES OF PLANT LIFE.\\ntheir defenders wants. A very large number of species\\nprotect themselves in this way. For the ants the plants\\nprovide (a) nec/ar, similar to that secreted in the flower\\n(i.e., a watery solution of various\\nsugars), but secreted by nectaries\\noutside the flower (b) fodder, in\\nthe form of hairs (fig. 230), often\\nof peculiar from, richly supplied\\nwith nutritive substances, grow-\\ning from special parts of the sur-\\nface, which are regularly eaten\\nby the ants and grow again, so\\nFig. 230. Fig. 231.\\nFig. 230. Bit of a section through the cushion (c, fig. 231) at base of leaf of Cecrofiia,\\nshowing the velvety hairs with which it is covered, and among them the egg-like\\nbodies, rich in proteids and fats, which the ants collect and carry into their nests in\\nthe interior of the stem. Magnified about 10 diam. After Schimper.\\nFig. 231. Apex of the hollow stem of a young Cecropia. a, the thin spot above a\\nleaf, which at b has been gnawed through by the ants to make their nests in the cavity\\nof the stem c, the cushion at base of leaf stalk where food bodies grow. See\\nfig. 230. Two-thirds natural size. After Schimper.\\nthat a constant supply is at hand (c) dwellings of various\\nsorts. Certain plants have the stems hollow throughout,\\nwith special modification of the structure at certain spots, so\\nthat an entrance to these hollows may be readily made (fig.\\nMore than three thousand are listed by Delpino.", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0274.jp2"}, "275": {"fulltext": "ANIMALS AS FOOD, FOES, OK FRIENDS. 269\\n231). In others, portions of the internodes are much en-\\nlarged and hollow sometimes only the internodes in the\\nregion of the flower clusters are thus transformed. In other\\nplants chambers are produced by the bladdery enlargement\\nof the under part of the leaf near the midrib (fig. 232). In\\nsome acacias the stipules are developed\\nas large hollow thorns, which the ants\\ninhabit.\\n381. 5. Crystals. Plants protect\\nthemselves against soft -bodied animals,\\nsuch as snails and slugs, by means of\\nthe sharp-pointed crystals which are\\npresent in the leaves of many species.\\nAccording to Stahl, all tissues contain-\\ning these crystals are avoided by such\\nanimals, but will be readily eaten by\\nthem after the crystals are removed.\\n382. Summary. Carnivorous plants\\nuse small animals, especially insects,\\nas food, capturing them by pitfalls,\\ntraps, or adhesive surfaces, and either\\ndigesting and absorbing the useful parts,\\nor after the slower decay, absorbing certain substances. Many\\nplants protect themselves against browsing animals by armor,\\nby distasteful or injurious juices, by mimicking distasteful\\nor hurtful plants, or by harboring fierce ants which attack\\nanything that disturbs the plant they have made their home.\\nFor the ants some plants provide not only shelter but food.\\nFig. 232.\u00e2\u0080\u0094 Under side of the\\nbase of the leaf blade of To-\\ncoca lanci/olia, showing\\nbladder on each side of mid-\\nrib, each with entrance at\\na, a. Natural size After\\nSchumann.", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0275.jp2"}, "276": {"fulltext": "II. REPRODUCTIVE ADAPTATIONS.\\nCHAPTER XXVI.\\nPROTECTION AND DISTRIBUTION OF SPORES\\nAND SEEDS.\\nThe present knowledge of reproductive adaptations among\\nthe fiowerless plants is very imperfect, though probably many\\nexist. This chapter, therefore, must discuss chiefly the\\nadaptations in the more complicated reproductive structures\\nof seed-plants which have been most studied, with only inci-\\ndental allusions to such arrangements in the lower plants.\\nI. Protection against bad weather.\\n383. By movements. Pollen unfitted to resist low tem-\\nperatures or wetting must be protected from rain, cold, and\\nsimilar conditions. When nectar is secreted in the flower as\\nan attraction to insects it is liable to be washed out by rain\\nunless access of water to the interior of the flower is pre-\\nvented. To avoid these dangers, many plants upon the\\napproach of unfavorable weather bend their leaves so as to\\nclose the flower (fig. 233), or arch the stalk so as to turn the\\nblossom into such a position that the rain or snow will not\\nreach the sporangia or the nectaries. These movements of\\nthe leaves and stalk are combined in various ways to meet\\nthe needs of each particular form. All of them are growth\\n270", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0276.jp2"}, "277": {"fulltext": "DISTRIBUTION OF SPORES AND SEEDS. 27 1\\nmovements, brought about by variations in light and tem-\\nperature, which act as stimuli. (See 244.)\\nII. Adaptation to distribution of spores.\\nThe fact that spores are found in every group of plants\\nfrom the lowest to the highest makes it probable that a great\\nFtg. 233. A, flower of California poppy (Esckscholtzia), opened in sunshine; B, the\\nsame, closed in wet weather. Natural size. After Kerner.\\nFig 234. A, aerial hypha of Pilobolus crystal/inus, with spore case. The hypha is\\nswollen beneath the spore case and very turgid. B, the same with spore case torn\\noff at base and being shot away by the violent escape of the mucilaginous contents of\\nthe hypha. Magnified about 10 diam. After Kerner.\\nvariety of ways will have been adopted by plants to secure\\ntheir distribution. The more important ways may be grouped\\nas follows\\n384. 1. By turgor and tension. Among the fungi, spores\\nare often forced out of the spore case by the pressure upon", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0277.jp2"}, "278": {"fulltext": "272\\nOUTLINES OF PLANT LLFE.\\nit of neighboring parts, increasing until the spore case rup-\\ntures suddenly and the spores are shot out like projectiles.\\nIn some plants the whole spore case is thrown off in this\\nfashion, often to the distance of a meter or more (fig. 234).\\nThe fungus which attacks and kills house flies in summer\\ncasts off the single spore from the end\\nof the stalk carrying it by the bursting\\nof the end of this stalk through ex-\\ncessive turgor (fig. 235). With the\\nspore goes the contents of the stalk,\\nso that it is surrounded by a mass\\nof mucilage, thus enabling it to adhere\\nto any object which it strikes.\\nFilaments carrying the\\nspores often twist upon drying\\nand thus jerk off the spores\\nas they suddenly slip past\\nsome obstruction. When\\nspores are produced in chains,\\nthere are devices to separate\\nB A them at maturity so that the\\nFIG.235-/J a fly killed by the fly fungus lightest breath may carry\\n(hm/ iis t M usees), stuck to wall by hyphae J\\nand surrounded by a halo of the spores, them away. The teeth around\\nIwo-thirds natural size. hyphae pro- J\\njecling into the air from the body of the the mOllth of the CaOSllle of\\nfly, from whose tips spores are being shot x\\noff Several are shown in various stages m0 SSeS Serve tO distribute the\\nof development. 1 he turgor of the en-\\nlarged end of hypha finally ruptures the S p res at opportune intervals,\\nattachment of the spore and it is shot off 1 L\\nsurrounded by the mucilaginous contents instead of having them\\nwhich cause it to adhere to any object\\nstruck. Magnified 200 diam C, a spore emptied Ollt all at OllCC (See\\nenveloped in mucilage. Magnified 420 r v\\ndiam. -After Kerner. fig. 46, A.) Ill SOIlie Cases\\nthe teeth, by their form and hygroscopic curvatures, serve to\\nsling out the spores to a short distance. In many ferns the\\nspore cases are furnished with a spring-like structure (the\\nannulus) along the greater part of the edge, which tends to\\nstraighten itself upon drying, thus rupturing the spore case.", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0278.jp2"}, "279": {"fulltext": "DISTRIBUTION OF SPORES AND SEEDS. 273\\nAfter bending backward for some distance until the tear\\ngapes wide, the spring suddenly straightens and hurls the\\nspores to a considerable distance (fig. 236).\\nFig. 236. Spore cases of the male fern {Aspidium Filix-mas) scattering the spores.\\nA closed B, burst by the drying of the annulus C, the annulus after becoming\\nstrongly recurved is just returning to a nearly straight form and the spores are thereby\\nbeing hurled toward B. Magnified about 65 diam. After Kerner.\\n385. 2. By water. In perfectly quiet water, distribution\\nof spores depends solely upon their own motor organs. Only\\nzoospores (see 264) are so furnished. For these a film of\\nwater is sufficient, and they may swim some distance over\\nwhat appear to be merely moist surfaces. Most of the algse\\nand fungi living in water form zoospores. Their production\\nis often controlled by external conditions, the formation of\\nnew individuals being thus provided for when the old are\\nthreatened with destruction.\\nIn flowing water and by currents, non-motile spores are\\nreadily distributed, and even relatively heavy spores may be\\ncarried long distances by water currents. The pollen of\\naquatic seed-plants is sometimes carried to the stigma by\\nwater currents, as in Vallisneria (fig. 237).\\n386. 3. By air currents. Spores may be readily carried\\nby the air on account of their small size and their ability to\\nwithstand dryness. Most spores float in the air for some\\ntime as dust particles, and the slightest current is adequate", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0279.jp2"}, "280": {"fulltext": "274\\nOUTLINES OF PLANT LIFE.\\nto lift many and carry them along. Spores of most non-\\naquatic fungi, mosses, and fernworts are distributed by air\\ncurrents. The pollen of some seed-plants, especially the\\ncommon forest trees, is carried in this way.\\nFig. 237.\u00e2\u0080\u0094 Pollination of eel-grass {Vallisneria spiralis). The large flower is a pis-\\ntillate one, with stigmas fringed on under side. About it are floating staminate flow-\\ners in various stages of development, having broken from submersed stems which\\nbore them. The ones on the right and left have the boat-shaped perianth lobes turned\\nback, stamens mature, and pollen exposed one has floated so that the pollen is\\nbrought into contact with the stigma of the pistillate flower. Magnified 10 diam\\nAfter Kerner.\\n387. 4. By animals, especially insects. It is the seed-\\nplants, particularly, which have adapted themselves to the\\ndistribution of spores by this means. The pollen must be\\ncarried to the ovules of gvmnosperms or to the stigmas of\\nangiosperms and lodged there. It has been clearly shown\\nnot only that adaptations for securing this result have been\\ndeveloped, but also that there have arisen various ingenious\\nadaptations to secure cross-pollination and to prevent close-\\npollination. (See 295.) Some of these may be here\\nenumerated.", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0280.jp2"}, "281": {"fulltext": "DISTRIBUTION OF SPORES AND SEEDS. 2?$\\n388. Adaptations for cross-pollination. (a) The sepa-\\nration of the stamens and pistils, staminate flowers and pistil-\\nlate flowers being produced upon different parts of the same\\nplant or even upon different plants of the same species (b) the\\nearly ripening of the stamens so that they discharge their\\nspores before the stigma of the same flower is exposed or\\nreceptive, or vice versa (c) arrangements preventing the\\npollen from reaching the stigma of the same flower, which\\nvary according to the different modes by which the transfer\\nof the pollen is made (d) the failure to form good seed\\nwhen close-pollination happens.\\n389. Adaptations for close-pollination. But close-pollin-\\nation, even though it results in weaker offspring, is better\\nthan entire failure to produce progeny. Therefore, some\\nplants permit close-pollination in the event of failure to\\nsecure cross-pollination, while a few have adaptations which\\ninsure it. Our common violets produce in the late spring\\nand early summer inconspicuous blossoms which do not open,\\ncontaining stamens with few pollen grains. These flowers,\\nhowever, produce seed abundantly, and always by close-\\npollination. Various other species have similar arrange-\\nments.\\n390. Adaptations to insects. The adaptations to secure\\ncross-pollination through the visits of insects are so numerous\\nand so varied, and the advantage in the number and weight\\nof seeds produced is so marked, that for most seed-plants\\ncross-pollination must be considered the far more desirable\\nprocess. Flowers are adapted to insect visitors in the fol-\\nlowing w T ays\\n391. (a) Food, etc. They provide for their visitors edi-\\nble substances, such as nectar and pollen, material for nest\\nbuilding, shelters, or breeding places.\\nThe pollen is often produced in great excess of the plant s own\\nneeds.", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0281.jp2"}, "282": {"fulltext": "2?6 OUTLINES OF PLANT LITE.\\n392. (b) Advertisements. They advertise the presence\\nof such attractions in two ways, which are sometimes com-\\nbined, and insects accustomed to visit flowers quickly learn\\nto know what the advertisements mean. (i) By color.\\nFlowers are so colored as to attract notice and this is fur-\\nther secured by the large size of individual flowers or by\\nmassing many small flowers into close clusters, (ii) By odor.\\nOdors are due to volatile oils, usually in the petals or sepals,\\noften curiously localized. Dusk- and night-blooming plants\\noften have heavy odors.\\n393. (c) Form and position of parts. Many plants by\\nthe form of their flower-leaves provide landing places for\\nwelcome visitors. Guides to the location of the nectar, in\\nthe form of grooves, folds, hairs, lines of color, etc., are\\noften present. The form and position of the stamens and\\npistils are often such as to insure the desired transfer of pollen.\\nThese positions may be permanent or they may be secured by\\nmovements at opportune times. Among the movements are\\nthose due to turgor and those due to the presence of motor\\norgans. In a very large number of cases, by the form of the\\nflower-leaves and the essential organs the plant is adapted to\\nvisitation by particular insects, and if these are not present,\\nor if their access is denied, constant failure to set seeds is the\\nresult. Thus one may distinguish plants adapted to bees,\\nmoths, butterflies, flies, birds, or even snails.\\n394. (d) Exclusion of unwelcome visitors. In addition\\nto provision for welcome guests must be enumerated the\\nmethods of excluding unwelcome guests, which on account of\\ntheir size and habits are unable to bring about the desired\\ntransfer of the pollen, while at the same time they rob the\\nplant of nectar or pollen provided for more acceptable visitors,\\n(i) Various obstructio?is within the flower may render access to\\nthe nectar impossible to the smaller and weaker insects, while\\nallowing others to reach it. Such obstructions are formed", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0282.jp2"}, "283": {"fulltext": "DISTRIBUTION OF SPORES AND SEEDS. 2JJ\\nby folds, hairs, and other outgrowths upon the flower-leaves\\nor on the essential organs (fig. 238). (ii) Obstructions out-\\nFig. 238.\u00e2\u0080\u0094 Flower of Cobeea scandens, halved; showing tu r ts of hairs on the base of\\nthe filaments, of which there are five these close the bottom of the corolla cup, where\\nnectar is secreted, against intruders. Three-fifths natural size. After Kerner.\\nside the flower may exclude crawling insects. Such are sticky\\nsurfaces and hairs (fig. 239), moats about the stem formed by\\ncup-shaped leaves holding\\nwater, or those formed by\\nwater in which swamp plants\\ngrow. (iii) The time of\\nblooming also prevents the\\nvisits of any insects except\\nthose flying at that particular\\nseason.\\nIII. Adaptations to the\\ndistribution of seeds.\\n395. After the ripening\\nFig. 239.\u00e2\u0080\u0094 Flower of a saxifrage (Saxifraga\\nOf the Seed Various devices controversa), protected against invasion\\nby the numerous sticky glandular hairs on\\nand forces Operate tO Scatter the flower stalk, ovulary, and calyx. Mag-\\nnified several diam. After Kerner.\\nthem at as great a distance as\\npossible from the parent, so that the young plants will not\\ncome into competition with the old ones or with each other.\\nThis object, which is secured in lower plants by the distri-\\nbution of the spores, can only be attained in seed-plants by", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0283.jp2"}, "284": {"fulltext": "278\\nOUTLINES OF PLANT LIFE.\\nscattering the seeds, which contain the young plants in a\\ndormant condition.\\nThe methods by which distribution is secured may be\\ngrouped as follows\\n396. 1 Distribution by tension and turgor. Some plants\\n(e.g., witch hazel) as they ripen the seed vessel, alter its tis-\\nsues in such a way that the contained seeds are compressed as\\nFig. 240.\u00e2\u0080\u0094 Elastic valves for slinging seeds. A, fruit of wild geranium (G. fialustre)\\nwith persistent calyx. The five carpels surround an elongated torus, from which they\\nbreak first at bottom curling upward suddenly they sling the seed out of the basal\\npart which has cracked along the inner side. B, fruit of touch-me-not (f\u00c2\u00bbi/ atie /s\\nnoli-\u00c2\u00bbie tangere), one sound, the other bursted. The carpels have curled up elasti-\\ncally from the base and slung out the seeds. Natural size. After Kerner.\\nit dries, and after it opens they are pinched out from the nar-\\nrowing valves, as a wet apple or melon seed may be shot from\\nbetween the thumb and finger. In others (e.g., touch-me-\\nnot and cranesbill) the parts of the seed pod shorten on one\\nside until the strain breaks them loose, when they suddenly\\nbecome elastically curled and sling the seeds contained to a\\nconsiderable distance (fig. 240). Somewhat similar causes,\\ni.e., curvatures due to unequal shrinkage or swelling of the\\nparts, enable some fruits with long awns or bristles to creep", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0284.jp2"}, "285": {"fulltext": "DISTRIBUTION OF STORES AND SEEDS. 279\\nover the ground or to bury themselves in it when alternately\\nmoistened and dried (fig. 241). The seed vessel of the\\nsquirting cucumber is so distended by the almost liquid pulp\\nsurrounding the seeds that it ejects the mass through the\\nopening formed by its separation from the stem.\\n397. 2. Distribution by water. In some plants\\nthis is secured by the fact that the fruits open only\\nwhen moistened. In such cases the seeds may be either\\nwashed out from the opening pods by rain, or may be\\nloosened in many other ways. The seeds are thus set\\nfree at the time best suited to their prompt germination.\\nSome plants, adapted to dis-\\ntribution by water, are pro-\\nvided with floats. These\\nfloats may consist either of\\nthe enlarged and bladdery\\nseed pod (or some portion of\\nit), or of the spongy, air-\\nfilled seed coat. The fruits\\nor seeds are thus made more\\nbuoyant and float upon the\\nsurface instead of sinking as\\nusual. Naturally, water-lov-\\ning plants are chiefly adapted\\nto distribution in this manner.\\n398. 3. Distribution by-\\nwinds. Some plants which\\nsecure their distribution by\\nwinds are only lightly attached\\nto the soil at maturity, so that they are readily uprooted and\\ncarried bodily, when dry, for considerable distances by the\\nwind. The transfer is facilitated by the incurving of the\\nbranches upon drying, so that the uprooted plant is more or\\nless spherical in outline, or by the fact that the plant is nor-\\nFig. 241. -Pieces into which the fruit of\\nstorksbill breaks. There are five of\\nthese each corresponding to a carpel and\\narranged on the sides of a prolonged\\ntorus as in A fig. 240. A when dry the\\nbeak is spirally coiled B. when moist.\\nThe base is hard and very sharp. Magni-\\nfied about 2 diam. After Noll.", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0285.jp2"}, "286": {"fulltext": "28o\\nOUTLINES OF PLANT LIFE.\\nmally spherical by the proportion of the branches. Such\\nplants are known as tumble weeds. Singly or aggregated\\nin large bundles they are rolled over plains and prairies for\\nlong distances, shaking out\\ntheir seeds as they go, or\\nopening their fruits when\\nmoistened.\\nAnother adaptation for\\ndistribution by the wind\\nis the small size of some\\nseeds. Those of some\\norchids are so diminutive\\nthat it takes 500,000 to\\nweigh 1 gram. Such\\nminute seeds are readily\\nblown long distances by\\nthe wind. Relative light-\\nness is also secured by the\\nconstruction of some seeds,\\nwhich are surrounded by a\\nvoluminous coat contain-\\ning many large air spaces\\n(fig. 242). Outgrowths\\nfrom parts of the seed coat\\nor pericarp also secure\\nthe same end. In such\\ncases the fall of the fruit or seed through the air is so retarded\\nthat it may be carried laterally some distance by the wind.\\nNo seeds, however small, float long in quiet air, since buoy-\\nancy is derived only from air-containing tissues. A flattened\\nform of the fruit or seed is very common, and this form is\\noften exaggerated by the formation of wings, i.e., of thin out-\\ngrowths from the surface (fig. 243). The center of gravity\\nin such cases is so placed that the plane of flattening will be\\nFig. 242. Seeds of an orchid i Va7i ia teres),\\nwith cells of seed coat bladdery and filled with\\nair. These seeds are ejected from the capsule\\nby the contortions of the hairs on its inner\\nfaces which curve and twist as the moisture in\\nthe air varies. Magnified 100 diam. After\\nKerner.", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0286.jp2"}, "287": {"fulltext": "DISTRIBUTION OF SPORES AND SEEDS. 28 1\\nnearly horizontal when the seed falls. These fruits or seeds\\nsink from 2 to 30 times as slowly as the same bodies without\\nthe wing. Sometimes special floats are used for this purpose,\\nA B\\nFig. 243.\u00e2\u0080\u0094 Fruits with wings. A fruits of ailanthus tree (A glandulosus), each carpel\\nwith double wing. B, fruits of a maple tree, each carpel with a single wing. Natural\\nsize. After Kerner.\\nas in dandelion and thistle (fig. 244). Hairs of the most\\nvarious origin are produced in such numbers and position as\\nto form either parachutes or tangled woolly envelopes to the\\nfruit or seeds (figs. 245, 246).\\n399. 4. Distribution by animals. To secure this there\\nare two general methods observable, (a) The seed or fruit\\nis either adapted for transport by adhering to the body of the\\nanimal or the seeds are surrounded by edible parts, and\\nat the same time so protected against the digestive juices that\\nthey may pass uninjured through the alimentary canal. A few\\nplants are distributed by animals which collect and hide their\\nfruits or seeds (e.g., the squirrels). The adhesion of fruits or\\nseeds to animals, especially to those which are provided with\\nfur, is generally secured either by surfaces made adhesive by\\nthe sticky secretion from glandular hairs, or by the develop-\\nment of outgrowths in the form of hooks or barbed prickles", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0287.jp2"}, "288": {"fulltext": "282\\nOUTLINES OF PLANT LIFE.\\n(figs. 247, 248, 249, 250). A few water animals and wading\\nbirds distribute seeds which happen to fall into the mud by\\nthe adhesion of this mud to their bodies.\\nThe fleshy fruits with edible parts are usually colored to\\nattract the notice of the fruit-eating animals. Seeds which\\nescape crushing by\\nthe teeth or grinding\\nin the gizzard are\\napt to be in condition\\nto germinate when\\nvoided. The seeds\\nof the mistletoe are\\nseparated from the\\nV V\\nFig. 245.\\nFig. 244.\\nFig. 244. Heads of fruits of the dandelion single fruits falling, exposing common\\ntorus and involucre. Natural size.\u00e2\u0080\u0094 After Kerner.\\nFig. 245.\u00e2\u0080\u0094 Fruits of a willow, burst, and allowing the seeds, each with a tuft of silky\\nhairs (coma), to escape. Natural size. After Kerner.\\npulp of the berry by the birds which eat them, and, sticking\\nto the bill, are wiped off on the branches of trees, where they\\ngerminate.\\nThe adaptation of plants to any one of these agents of dis-\\ntribution is likely to be more or less effective with other\\nagents. For example, the tufts of hairs which increase the\\nbuoyancy of the seed in air would be equally effective should", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0288.jp2"}, "289": {"fulltext": "DISTRIBUTION OF SPORES AND SEEDS. 283\\nFig. 246. A fruit of Barbadoes cotton, open, exposing the voluminous hairs (commer-\\ncial cotton) which clothe the seeds. Natural size.\u00e2\u0080\u0094 After Kerner.\\nA B\\nFig. 247. Fig. 248.\\nFig. 247.\u00e2\u0080\u0094 Fruit of Agrimonia, halved; showing torus, carrying calyx and withered\\nstamens above, covered with hooks, and enclosing the hard pericarp, with a single\\nseed. A pistil which did not mature lies to the right. Compare torus in fig. 175.\\nMagnified about 8 diam. After Baillon.\\nFig. 248. Fruit of tick trefoil (Desmodium Canadense). A pods which separate into\\nsections, each containing one seed. They are covered with stiff hooked hairs, some\\nof which are shown enlarged at B. A, natural size. B, magnified about 20 diam.\\nAfter Kerner.", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0289.jp2"}, "290": {"fulltext": "284\\nOUTLINES OF PLANT LLFE.\\nthe seed chance to alight upon water, or they may suffice to\\nentangle the seed in the fur of animals.\\n400. Adaptations for germination. Adaptations for dis-\\ntribution not infrequently also secure advantage in germina-\\ntion. It is important for\\nmany seeds that they be\\nanchored to the ground when\\nthey have once been trans-\\nported, so that they may not\\nbe subject to further disturb-\\nance. Such anchorage is\\nsometimes secured by the\\ntransformation of the outer\\nlayer of cells into mucilage,\\nso that the seed, upon be-\\ncoming wet, is stuck fast to\\nthe soil or by the tufts of\\nhair which, once wetted,\\nto the surface of the\\nfruit enlarged, showing barbed awns, rep- T u t J i .1.1\\nresenting the calyx lobes, by which it earth; or by barbed bristles\\nadheres to animals. A natural size B, i i\\nmagnified 2 h diam.\u00e2\u0080\u0094 After Kerner. and hygroscopic awns Which,\\nFig. 250.\u00e2\u0080\u0094 Fruit of cockle-bur iXanthium j\\nstrum*rzum),hdved, showing two seeds, having become entangled\\nthe upper of which usually germinates a 1\\nyear later than the lower. Natural size among the graSS, WOrk a\\npointed seed body deeper\\nby every change of moisture (fig. 241).\\n401. Summary. Plants have developed many ways for\\nprotecting and distributing their spores and seeds. Pollen is\\noften protected against rain by closure of the flower-leaves or\\nbending of the stalk. Fungus spores may be shot off or\\nslung off. Many ferns sling out their spores from the cases.\\nWater and air currents carry spores. Insects are also efficient\\ndistributors, especially for the seed-plants, which provide food,\\nshelter, nest-building materials, etc., to secure their aid.\\nThis they advertise by color and odor. By irregular form\\nB A\\nFig. 249. Fig. 250.\\nFig. 249. A, cluster of fruits of Spanish\\nneedles {Bidens bipinnata). B, a single Cllllg", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0290.jp2"}, "291": {"fulltext": "DISTRIBUTION OF SPORES AND SEEDS. 285\\nthey also provide suitable landing places, and exclude ineffi-\\ncient visitors by obstructions both inside and outside the\\nflower.\\nSeeds are distributed by being pinched or slung out by the\\ndrying seed pod, or shot out with the juice of the seed vessel\\nwhen it breaks loose. Currents of water may float fruits or\\nseeds long distances winds also carry them, especially if light\\nor winged. Animals transport fruits or seeds which adhere to\\ntheir bodies in mud or by hooks. Seeds in edible fruits may\\nalso escape destruction and be dropped far from the place\\nwhere they were eaten.\\nConclusion. Study of plants in relation to their surround-\\nings, therefore, yields the conclusion that these organisms are\\nwonderfully plastic, responding either temporarily or perma-\\nnently to every change in conditions. It is greatly to be de-\\nsired that the too common thought of plants as only things to\\nbe classified may be replaced by the conception of them as\\nbeings at work, to be studied alive.", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0291.jp2"}, "292": {"fulltext": "", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0292.jp2"}, "293": {"fulltext": "APPENDIX I.\\nDIRECTIONS FOR COLLECTING AND\\nPRESERVING MATERIAL.\\nThose who cannot collect the plants they require can order them from the Cambridge\\nBotanical Supply Co., 1286 Massachusetts av., Cambridge, Mass.; or the Ithaca\\nBotanical Supply Co., Ithaca. N. Y. Orders should be placed in advance of the\\ncollecting season to insure obtaining the material.\\nPleurococcus. For this and similar one-celled algae, collect pieces\\nof shaded fence boards near the ground, or flakes of bark from\\nthe north side of trees in groves and parks, which show a bright\\nyellow-green color. These may be preserved dry.\\nOscillaria. Search in drippings about watering troughs, city\\ngutters where water stands, or any open drain which contains\\norganic matter decaying in stagnant water. A glass jar or\\naquarium in which water plants have decayed will usually con-\\ntain this plant. It may be recognized by its bluish or blackish\\ngreen color, and often occurs in coherent films or thicker masses.\\nIt may be obtained fresh at any time of year, either out doors or\\nin the laboratory.\\nRivularia. Collect in midsummer or later the larger water\\nplants to whose leaves and stems adhere jelly-like lumps of a\\ndirty green color, from the size of a pinhead to 1-2 cm. in\\ndiameter. The margins of lakes, pools, and slow streams furnish\\nthe best localities.\\nNostoc colonies form similar jelly masses, commonly larger and\\nfree floating or attached. Preserve both like the following.\\nSpirogyra or Zygnema. Search in spring or early summer in slow\\nstreams fed by springs. It will be recognized when in vegetative\\ncondition by rich green color and slippery feel. Under the\\nmicroscope the form of the chloroplasts will show the genus.\\n287", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0293.jp2"}, "294": {"fulltext": "288 APPENDIX.\\nWhen conjugating it often loses the deep green and becomes\\nyellowish, and the filaments seem to be double.\\nThis condition can be recognized under the lens. Spirogyra\\nmay often be obtained all through the year in pools and springs.\\nIt should be preserved in the following solution: Camphor water\\n50 cc. water 50 cc; glacial acetic acid 0.5 cc. copper nitrate\\n2 gm. copper chloride 2 gm.\\nCladophora. Species of this genus may be found attached to\\nsticks and stones at the edge of lakes or pools, It often covers\\nthese completely with a thick mat of long, yellowish green,\\nbranched filaments. It may be found throughout the growing\\nseason. For winter use preserve in same solution as above.\\nPolysiphonia. All species are marine, and any common species\\nwill serve, They are found in reddish brown, feathery tufts 2-\\n10 cm. high, on other larger sea-weeds, or on piles and stones,\\nabout low-water mark. They collapse completely when with-\\ndrawn from the water.\\nThe plants should be fixed in one per cent, chromic acid (or in a\\nsaturated solution of picric acid in sea-water) for 12-24 hours,\\nwashed in sea-water as described for C/iara, and hardened in 40,\\n60 and 80 per cent, alcohol successively, remaining in each 6-\\n24 hours. They may be preserved in the latter. They may also\\nbe preserved in formalin.\\nFucus. All species are marine and any one will serve. The\\ncommonest is Fucus vesiculosus (fig. 42), which may be found on\\nrocks between tide marks. It is of olive-brown color, with\\nswollen tips to many of the branches, and bladders in pairs along\\nthe thallus. Plants may be obtained fresh at almost any season.\\nVarious species of brown sea-weed may be found fresh at the\\nfish stores of all large cities, whither they are sent as packing.\\nMucor or Rhizopus. Saturate a piece of bread with water and\\nkeep it under a bell jar, in a warm place, for a few days.\\nSeveral species of molds will appear, the most common of which\\nis the black mold, Rhizopus nigricans. This may be recognized\\nby its white fluffy mycelium, on which arise tufts of erect hyphae\\ndeveloping at tips spherical sporangia, at first white, later black.\\nThese tufts occur at intervals along a stolon-like hypha. The\\nsame mold may be found on rotting vegetables and fruits,\\nespecially sweet potatoes and lemons, and may be raised more\\nrapidly on bread by sowing spores. It will be followed by the\\ngreen mold, Penicillium glaucum, and often later by other", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0294.jp2"}, "295": {"fulltext": "COLLECTING AND PRESERVING MATERIAL. 289\\nspecies. Since the plants may be grown promptly, the material\\nused should be living.\\nMicrosphaera or Uncinula or Erysiphe. Any species of mildew\\nwill answer. Microsphcera grows everywhere on the leaves of\\nthe cultivated lilac. Erysiphe is abundant on the leaves of blue\\nor white vervain {Verbena hastata and V. urticcefolid) and many\\nComposite. Uncinula attacks leaves of many willows. About\\nmidsummer, when the fungus has a white powdery aspect, gather\\nleaves and dry them under light pressure. Later, gather leaves\\nof the same species showing yellow and black dots (the fruits) on\\nthe mycelium. Preserve in the same way.\\nCystopus portulacae. This species is abundant throughout the\\nsummer on leaves and stems of purslane {Portulaca oleracea)\\nwhich grows in every garden and cornfield. Another species\\ngrows in late spring on shepherd s-purse {Capsella bursa-pastoris)\\nand another on the pigweeds {Amaranthus sp.). Any one will\\nanswer. The species on Capsella {Cystopus candidus) only oc-\\ncasionally forms resting spores in that host. They may be found\\nin abundance in the flowers of radish which become much enlarged\\nand distorted when this fungus is parasitic thereon. All species\\nmay be known by the white blisters formed by lifting the skin of\\nthe host. Preserve in formalin or alcohol leaves and stems of\\nhost bearing blisters. Some may also be dried.\\nLichens. Any common foiiose species which forms apothecia\\nabundantly will answer. A bright gray species with black apo-\\nthecia {Physcia stellaris) is abundant on tree trunks, as is also a\\nyellowish species with orange apothecia {Theloschistes polycarpa).\\nThese may be collected at any convenient time, and kept dry.\\nBesides these, collect other foiiose forms; also species of Cladonia\\ngrowing on the ground, with body much lobed and the apothecia\\ncoral-red knobs on upright gray stalks; also species of Usnea,\\nclothing the branches of trees with gray-green shrub-like or hair-\\nlike tufts.\\nMushroom. Any species with cap and gills will answer. They\\nmay be found in woods throughout the summer and especially\\nin late summer or autumn during a rainy season following\\ndrought. Only the fructification need be collected. Select a\\nsmall firm species with well defined stalk, cap and gills. Col-\\nlect fructifications in all stages of development from young to\\nmature. Preserve as soon as gathered in formalin or 70 per cent,\\nalcohol.", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0295.jp2"}, "296": {"fulltext": "29O APPENDIX.\\nOther Hymenomycetes. Collect fleshy cap fungi with hanging\\npoints instead of gills (Hydnum, fig. 217), or intersecting plates\\nforming tubes (Boletus). Preserve these as mushroom. Collect\\nalso the woody bracket fungi (Polyporus, fig. 218), which grow on\\nrotten trees and fallen limbs, showing innumerable fine tubes\\nunderneath. Preserve dry. Also the much branched firm-\\nfleshed Clavaria (fig. 215). Preserve as mushroom. All will be\\nfound in damp woods.\\nMarchantia. Common on wet ground and rocks, or even in\\ndrier places among grass in the shade of walls or fences. It\\nmay be recognized by flattish green body about 1 cm. wide and\\n5-8 cm. long, attached by silky hairs. At some times it bears on\\nthe upper surface sessile cups containing green grains, and sends\\nup erect slender sexual branches which spread out into flat heads\\n6-8 mm. across, some scalloped at edge and some with finger-like\\nrays. When cups or sexual branches are present no other liver-\\nwort can be mistaken for it. A very similar one, except in these\\nparts (Conocephalus conicus) may be distinguished by its larger\\nsize and larger stomata, looking like needle pricks over the sur-\\nface, while those of Marchantia are just visible. It may be used\\nfor the vegetative parts. Collect in July. Free from dirt as\\nmuch as possible, and preserve in formalin or 70$ alcohol.\\nPorella. Abundant everywhere on the bases of trees especially\\nin low grounds or wet bottom lands. It may be recognized by\\nits dirty-green pinnately branched shoots, 1-2 mm. wide, with\\ncrowded overlapping rounded leaves. The plants are always in-\\ntricately interwoven. Flakes of the bark may be peeled off with\\na broad knife or chisel, taking care not to tear up the plants into\\ntoo small patches. Collect in summer. Preserve dry, after dry-\\ning under light pressure. Some should be kept in formalin or\\nalcohol for demonstration of finer structure of sex organs.\\nMnium. Any species of the genus will do. The commonest\\nspecies eastward is M. cuspidatum. It is abundant everywhere in\\npatches on shady banks and in open woods about the bases of\\ntrees. It may be recognized by the yellow or orange oval cap-\\nsule, thin and irregularly wrinkled when dry, horizontal or pen-\\ndent on a stalk 2-3 cm. long. The leaves are broadly oval, with\\nfine sharp teeth under lens, and a distinct midrib. When moist\\nthe leaves are rather pale green, and not crowded or overlapping.\\nWhen dry the clump is a dull, dirty green, and the leaves are\\nmuch curled and twisted, expanding quickly when wetted. The", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0296.jp2"}, "297": {"fulltext": "COLLECTING AND PRESERVING MATERIAL. 29 1\\nmale and female organs are in the same cluster, at the apex of\\nthe axis. Under the microscope the species may be recognized\\nby the orange inner peristome with double rows of perforations\\nin the membrane below the segments. Preserve as directed for\\nPorella. Almost any similar moss will serve equally well, espe-\\ncially the common species of Bryutn.\\nAdiantum. Gametophytes of any fern will answer. They are\\nfiat green heart-shaped bodies 2-5 mm. in diameter, attached to\\nsoil by rhizoids. They may be collected on fern pots or grown\\nin greenhouses, or may be obtained from supply company named.\\nEspecial care should be taken to have some young sporo-\\nphytes still attached to gametophytes. The sporophytes of\\nthe maidenhair fern are easily recognized by the peculiarly\\nbranched leaf. The stem is wholly underground. Each leaf\\nhas a slender polished stalk which forks into two equal\\nbranches these fork, one branch of each pair growing straight\\nand bearing leaflets while the other again forks in the same way\\nand so on until 4-8 branches have been formed on each half.\\nCollect underground stems and roots, loosening them gently and\\nwashing off dirt carefully to avoid destroying all root tips and\\nhairs. Preserve these in alcohol or formalin. Gather leaves\\nwhen the crescent-shaped fruit dots at edges of leaflets are yel-\\nlowish brown (August). Preserve by drying, spreading out\\neach leaf to show its mode of branching clearly.\\nCaltha. This plant is common in wet meadows and swamps\\nnorthward. It is 15-30 cm. high, smooth, with rather coarse\\nhollow ribbed stems, orbicular or kidney-shaped alternate leaves,\\nwith broad clasping base to the petiole, and numerous bright\\nyellow flowers 20-25 rn m in diameter, produced for two weeks\\nor more in April or May. Gather entire plant; wash the roots.\\nPreserve a few plants and an extra supply of flowers and fruits\\nin alcohol or formalin. Dry most of the entire plants.\\nLathyrus. The sweet pea is grown in almost every flower gar-\\nden and is known everywhere. Flowers and leaves of as great\\nvariety as desired may be preserved at the proper season in\\nsummer in alcohol or formalin. Or, simple flowers may be se-\\ncured at greenhouses.\\nStems. The various sorts recommended may be collected at\\nany convenient time and preserved in fluid.\\nSeeds. The most useful seeds for laboratory work are Indian corn,\\nwheat, buckwheat, castor bean (Ricinus), white lupine, {Lupinus al\u00c2\u00bb", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0297.jp2"}, "298": {"fulltext": "292 APPENDIX.\\nbus), scarlet runner {Phaseolus), broad bean {Vicia fabd), hemp,\\nwhite mustard. These should be obtained fresh each year, as they\\ndeteriorate more or less with age. Those which cannot be had\\neverywhere (such, perhaps, as lupine, castor bean, scarlet\\nrunner, and broad bean) may be purchased of seedsmen in large\\ncities. See advertisements in magazines.\\nPotted plants. Such as are grown in window gardens or all\\ngreenhouses will suffice. A commercial greenhouse, if accessi-\\nble, will raise tomato, castor-bean, bean, and sunflower plants as\\nordered, and will furnish active young plants at any season re-\\nquired, in case pupils cannot grow them either at school or home.\\nMalt. Can be obtained ground or unground at any brewery,\\nor may be made by sprouting barley until the seedlings appear\\nand then drying at about ioo\u00c2\u00b0 C.", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0298.jp2"}, "299": {"fulltext": "APPENDIX II.\\nAPPARATUS AND REAGENTS.\\nThe chemicals required are so few that in most cases they\\nmay be most conveniently obtained through local dealers. It is\\ndesirable, however, to order apparatus from dealers who make a\\nspecialty of manufacturing or supplying optical, chemical, and\\nphysical apparatus. Schools are entitled to import such appara-\\ntus free of duty, and by doing so through importing firms a large\\npart of the cost may be saved. The list is given here for its\\nconvenience as a summary. The amounts necessary are not\\nspecified as they vary with the size of classes, and the teacher\\nwho is prepared to conduct the experiments can readily deter-\\nmine how much is needed.\\nCHEMICALS.\\nAcetic acid. Used for fixing protoplasm.\\nAlcohol. Large schools should buy in barrel lots free of reve-\\nnue tax. For regulations apply to the revenue collector of the\\ndistrict in which the school is situated, or to the Secretary of the\\nTreasury.\\nAmmonium hydrate (ammonia).\\nBarium hydrate. For making baryta water; or this can be ob-\\ntained fresh as needed from druggist.\\nChromic acid. Used in fixing and decalcifying.\\nCorn starch. As prepared for table or laundry.\\nFormalin. This is a 40 per. cent solution of formaldehyde in\\nwater. Dilute solutions can be prepared as needed. Most\\nplants require a 10 per cent solution, i.e., formalin 1 part, water\\n9 parts.\\nGrafting wax. Made as follows Melt together resin (by\\n293", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0299.jp2"}, "300": {"fulltext": "294 APPENDIX.\\nweight) 4 parts, beeswax 2 parts, tallow 1 part; mix well; pour\\ninto a pail of cold water; grease the hands and pull till nearly\\nwhite. In using it should be handled with greased fingers to\\nprevent its sticking to them.\\nIodine. Either solid, from which the tincture can be prepared\\nby dissolving a few flakes in alcohol, or the tincture may be pur-\\nchased.\\nMercury. For directions for keeping it clean and dry, see\\nBotanical Gazette 22 471. Dec. 1896.\\nParaffin. A common quality, melting at about 65 C.\\nPhenolphtalein. A few grams will last a long time.\\nPotassic hydrate. May be bought in sticks and the solution\\nmade, but it is more convenient to buy the liquor potasses of\\ndruggists.\\nSodium chloride. Table salt is pure enough.\\nVaseline.\\nAPPARATUS FOR MORPHOLOGY.\\nDissecting microscopes. Each pupil should be provided with one.\\nA most effective low-priced dissecting microscope was designed\\nby the author and is manufactured by several firms. In no case\\nhas the author any financial interest in the instruments. The\\nstand T I, manufactured by the Bausch Lomb Optical Co.,\\nRochester, N. Y., with i-inch lens, and a similar one by Queen\\nCo., Philadelphia, have been approved by the designer. Many\\nforms offered to schools by jobbers are not worth buying.\\nCompound microscopes. The school should be supplied with at\\nleast one good compound microscope for demonstrations, and as\\nmany more as can be profitably used. If the teacher is capable\\nof using such instruments properly he will be able to select it\\nwisely with such advice as he may obtain from personal acquaint-\\nances on whose judgment he can rely. S hools are advised to\\ndeal directly with manufacturers of established reputation.\\nScalpels. Each pupil should be provided with a sharp knife\\nwith slender blade for dissection. It is desirable for the school\\nto furnish scalpels of suitable form. The slender blades, 3-3.5\\ncm. long on cutting edge, are recommended.\\nForceps.\u00e2\u0080\u0094 Straight form, with smooth points, will be found use-\\nful, though not indispensable.\\nNeedles. Each pupil should have a pair of needles (No 6,", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0300.jp2"}, "301": {"fulltext": "APPARATUS AND REAGENTS.\\n295\\nsharps) with the eye end set into a soft pine penholder or similar\\nhandle. They must be kept sharp on a fine od-s.one\\nDrawing materials.-A medium penal (No. 3 or M) and ve 7f\\nhard one (No. 6 or 6 H) should be used and kept sharp. Slips of\\nheaviest linen ledger paper lb.) out r 4 X 8 em. are reeom-\\nmended. Only one drawing should be put on a sl.p.\\nAPPARATUS FOR PHYSIOLOGY.\\nSinee much of the apparatus needs to be put together by the\\n,Tl Te reauisites are mainly tools and a good supply of tub-\\nTg both glarAndrubber, bottles, and be,, jars. The following\\nwill enable the foregoing experiments to be earned out.\\nLb -Hammer, fine saw, three or four eh.sels, assorted files,\\nbra and assorted bits, screw-driver, smooth ng plane.wh\\nSupply of nails (especially finishing nails) and screws will be\\n7 ^.-A little capillary tubing (0.5 mm. bore) will\\nbe needed. Most used sizes are 5 mm. (3 mm. bore) mm\\n5 mm. bore.) Some larger sizes (13 and .9 mm.) will also be\\nUS 1 U L, ft**.-3 and 5 mm. bore mostly some of .0 and .5\\nmm. bore.\\nBottles \u00e2\u0080\u0094Wide-mouthed, various sizes, up to I liter.\\nrllT/^.-Jelly glasses answer well. Odd lids and glass dishes\\nfrom homes and stores can be made useful.\\n^.-Assorted sizes. Several rubber stoppers, sizes 8, 10, 12,\\nvhole, are desirable.\\n*r,.-Several sizes are necessary 15 X 20 and 20 X 3\u00c2\u00b0 cm.\\nwill be found useful also at least one 30 X 50 em. All should\\nhave ground rim and tubulure at top.\\nFunnels.-GX.ss, assorted sizes. 6, 8, and cm. diam. are\\nmost used there should also be two or three larger ones.\\nFilter paper.-Buy cut filters 15 and 18 cm. in diameter\\nr*eJJeters.-ShoM be graduated in degrees, -10 to 100\\nC, with milk-glass scale.\\nTest tubes.\u00e2\u0080\u0094 1 X 15 cm. is a convenient size.\\n7 -tubes.\u00e2\u0080\u0094 Two sizes, 5 and 10 mm. bore.\\nBunsen burners.-U gas is not available, gasolene burners\\nshould be substituted.", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0301.jp2"}, "302": {"fulltext": "296 APPENDIX.\\nMarble. A plate 25 X 25 X 2.5 cm., polished on both sides. It\\ncan be re-polished after etching and used as often as desired.\\nFilter pump. Can be used if water service is available, or if a\\nhead of 5 m. can be secured by tank. Korting s is excellent.\\nRulers. 30 cm. long, graduated in millimeters.\\nBrushes.\u00e2\u0080\u0094 Camelhair brush of large size, and sablehair, smallest,\\nare useful.\\nPins. Ordinary toilet pins.\\nTin tube.\u00e2\u0080\u0094 3 X 15 cm. See experiment 20.\\nAbsorbent cotton. Also a roll of cotton batting.\\nSheet /W.\u00e2\u0080\u0094 Light weight, used by plumbers.\\nPlate glass.\u00e2\u0080\u0094 Cul into pieces 20, 25, and 35 cm. square.\\nPine sawdust and clean sand.\u00e2\u0080\u0094 For germinating seeds.", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0302.jp2"}, "303": {"fulltext": "APPENDIX III.\\nREFERENCE BOOKS.\\nThe following books will be found useful to teacher or pupil or\\nboth, and are recommended as suitable reference books for the\\nschool library. The list is not intended to be exhaustive, nor\\ndoes it include books for popular reading.\\nFOR GENERAL REFERENCE.\\nerner Natural history of plants. New York Henry Holt\\nCo. $15.00. (Translated by Oliver.)\\nStrasburger, Noll, Schenck and Schimper Text-book of\\nbotany. New York The Macmillan Co. $4.50. (Trans-\\nlated by Porter.)\\nRennett and Murray Handbook of cryptogamic botany. New\\nYork Longmans, Green Co. $5.00.\\nVines A student s text-book of botany. New York The Mac-\\nmillan Co. $3.75.\\nSachs Lectures on the physiology of plants. New York The\\nMacmillan Co. $7.00. (Translated by Ward.)\\nGoebel Outlines of classification and special morphology. New\\nYork: The Macmillan Co. $5.50. (Translated by Garnsey\\nand Balfour.)\\nWarming: Handbook of systematic botany. New York: The\\nMacmillan Co. $3.75. (Translated by Potter.)\\nGray Systematic botany. New York The American Book Co.\\n$2.00.\\n^_J3essey Botany, Advanced Course. New York Henry Holt\\nCo. $2.20.\\nGeddes Chapters in modern botany. New York Charles\\nScribner s Sons. $1.25.\\n297", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0303.jp2"}, "304": {"fulltext": "290 APPENDIX.\\nCampbell Evolution of plants. New York The Macmillan Co.\\n$1.25.\\nCoulter Plant relations. New York D. Appleton Co.\\n$1.10.\\nPlant structures. New York D. Appleton Co. $1.20.\\nWarming: Lehrbuch der okologischen Pflanzengeographie. Ber-\\nlin: Gebr. Borntrager. (A German translation by Knoblauch.\\nAn English translation is now in preparation.)\\nPfeffer Pflanzenphysiologie. Ed. II., vol. 1. Leipzig: Wil-\\nhelm Engelmann. M. 20. (An English translation is now in\\npreparation by Dr. A. J. Ewart.)\\nVines Lectures on the physiology of plants. New York The\\nMacmillan Co. $5.00.\\nGoodale Physiological botany. New York The American\\nBook Co. $2.00.\\nFOR LABORATORY DIRECTIONS.\\nBergen: Elements of botany. Boston: Ginn Co. $1.10.\\nSpalding Introduction to botany. Boston D. C. Heath Co.\\n80 cts.\\nMacbride Lessons in elementary botany. Boston Allyn\\nBacon. 60 cts.\\nMacDougal Experimental plant physiology. New York Henry\\nHolt Co. $1.00.\\nArthur Laboratory exercises in vegetable physiology. Lafay-\\nette, Ind.: Kimmel Herbert. (Pamphlet.) 35 cts.\\nDarwin and Acton Practical physiology. New York The\\nMacmillan Co. $1.60.\\nArthur, Barnes and Coulter: Plant dissection. New York:\\nHenry Holt Co. $1.20.\\nGanong The teaching botanist. New York The Macmillan\\nCo. $1.10.", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0304.jp2"}, "305": {"fulltext": "OUTLINE OF CLASSIFICATION. 301\\nSubkingdom II. BRYOPHYTA. Bryophytes. Mossworts.\\nClass I. HepaticaD. Liverworts.\\nOrder 1. Ricciales,\\nRiccia.\\nOrder 2. Marchantiales. Liverworts.\\nMarchantia. Lunularia.\\nOrder 3. Anthocerotales. Horned liverworts.\\nOrder 4. Jungermanniales Leafy liverworts. Scale mosses\\nPorella.\\nClass II. Musci. Mosses.\\nOrder I. Sphagnales. Peat mosses.\\nSphagnum.\\nOrder 2. Andreceales.\\nOrder 3. Archidiales.\\nOrder 4. Bryales. True mosses.\\nBryum. Mnium. Hypnum.\\nSubkingdom III. PTERIDOPHYTA. Pteridophytes.\\nFernworts.\\nClass I. Filicineae.\\nOrder 1. Filicales. True ferns.\\nAdiantum. Pteris. Aspidium. Asplenium.\\nOrder 2. Hydropteridales Water ferns.\\nClass II. Equisetineae. Horsetails. Scouring rushes.\\nEquisetum.\\nClass III. Lycopodinese.\\nOrder 1. Lycopodiales. Ground pines.\\nLycopodium.\\nOrder 2. Selaginellales. Club mosses.\\nSelaginella.\\nSubkingdom IV. SPERMATOPHYTA. Seed plants.\\nClass I. Gymnospermae. Gymnosperms.\\nOrder I. Cycadales. Cycads.\\nCycas.", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0305.jp2"}, "306": {"fulltext": "302 APPENDIX.\\nOrder 2. Coniferales.\\nPines, spruces, larches, firs, etc.\\nOrder 3. Gnetales.\\nWelwitschia.\\nClass II. Angiospermae. Angiosperms.\\nSub-class I. Monocotyledones. Monocotyledons.\\nOrders several. Lilies, irises, grasses, sedges, rushes\\npalms.\\nSub-class II. Dicotyledones. Dicotyledons.\\nOrders numerous. Most herbs with net-veined leaves\\ndeciduous shrubs and trees.\\nI", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0306.jp2"}, "307": {"fulltext": "INDHX.\\nAll references are to pages. Italic figures indicate illustrations.\\nAbsorption, limit of 128; of gases\\n139; of water 242\\nAcacia, shoot of 103\\nAccessory fruits 222\\nAdaptation 1 17, 227\\nAeration 146\\nAgrimonia, fruit of 283\\nAilanthus, fruit of 281\\nAir, composition 231, plants 125\\nAldrovandia vesiculosa 265\\nAlgse 254, 255; filamentous 17;\\nfission 6; larger 23; yellow-\\ngreen 11\\nAllium, stem 89\\nAloe socotrina 241\\nAlternation of generations 41\\nAmanita phalloides 192\\nAmorphoph alius 10 4\\nAnagallis, capsule of 222\\nAngiosperms 198\\nAnther 202, 203, 204\\nAnthyllis 112\\nAnts 267\\nApodanthes 259\\nApple 224, twi g of 78\\nArbor- vitas, shoot of 84\\nArmor, 266\\nArtemisia, hairs of 240\\nAsh, calyx and pistil of 200\\nAsparagus, twig of 79\\nAspidium 195\\nAsplenium bulbiferum 212, spore\\ncases 273, gametophyte of 53\\nAssimilation 137\\nBacteria 9, 10\\nBacterium aceti 10\\nBarberry 267\\nBark 92, 93, 94\\nBast, secondary 91, 92\\nBazzania Novae- Hollandiae 45\\nBean, roots of 176\\nBeech, rootlet of 254\\nBeet, stoma of 110\\nBegonia 88\\nBellflower 171, capsules of 221\\nBidens, fruits of 284\\nBladderwort 263\\nBracts 107\\nBranches, dwarf 77, leaf-like 77\\nBranching 19, 31, 43; monopodial\\n74; of leaves 103, 104 of mosses\\n48 of roots 83 of shoot 73\\nBryony SO\\nBryum 194, capsules of 50\\nBudding 31, 187\\nBuds 73, 212; adventitious 70, 76;\\naxillary 74; brood 211 dormant\\n76; fleshy 212; lateral 74; on\\nroots 69\\nBulb 76, 244\\nBulblets 79\\nButomus, anther of 203\\nCalamus, root of 64\\nCalifornia poppy, ovules of 201\\nCalyptospora 37\\nCalyx 206\\nCampanula pusilla 171; rapuncu-\\nloides 221\\nCapsule 200,_ 221, 222\\nCarbon dioxid 139\\nCarex stricta 267\\nCarnivorous plants 261\\nCarpels 197\\nCarrot, chromoplasts of 4\\nCaulerpa 20, 21\\nCecropia 268\\n303", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0307.jp2"}, "308": {"fulltext": "3Q4\\nINDEX.\\nAll references are to pages. Italic figures indicate illustrations.\\nCells I, 2, 155, 167; division 16;\\ngrowth 154; guard no; naked\\n119, 164; union of 218; wall 2, 4\\nCellulose 4\\nCentrifuge 174\\nCilia 10\\nCinchona, bark of 93; stem of 91\\nCinnamon flower 201/.\\nCirsium, pollen grains 205\\nCheiranthus, hairs of 86\\nChelidonium 167\\nCherry, fruit of 223; stem of 92\\nChlorophyll 3, 140\\nChloroplasts 3\\nChondromyces serpens 253\\nCladonia furcata 257\\nCladophora 19\\nClambering plants 250\\nClavaria aurea 192\\nClimbing plants 249\\nClover 256\\nCobaea scandens 277\\nCockle bur, fruit of 284\\nColonies, of Chondromyces 253;\\ngelatinous 6, 7\\nColor 24\\nContractility 1 17\\nConvolvulus, hairs of 240\\nCoprinus 191\\nCork 91 cambium 66, 91\\nCorm 77\\nCorn, cockle 199; bundles of In-\\ndian 90\\nCorolla 206\\nCortex 27, 61, 64, 85, 86, no\\nCotton, fruit of 283\\nCowberry 37\\nCrataegus, shoot of 100\\nCrowfoot 162\\nCrystals 151, 269\\nCuttings 214\\nDandelion, fruit 282; pollen grains\\n205\\nDatura stramonium, anther of 203\\nDehiscence 202; of seed pods 278\\nDesmids 14\\nDesmodium, fruit 283; gyrans 181\\nDevelopment, rate of 234\\nDiatoms 12, 13\\nDigestion 137, 143\\nDionaea muscipula 183, 264\\nDistribution of seeds and spores\\n270\\nDodder, European 258\\nDormant period 234\\nDrosera rotundifolia 264\\nDuration, of growth 163; of shoot\\n81\\nEcology 115, 226\\nEctocarpus, filament of 254\\nEdelweiss, hairs of 24O\\nEel grass 274\\nElaeagnus angustifolia 241\\nElatine, stem of 87\\nElm, buds 75\\nEmbryo 219, sac 201\\nEmpusa Muscse 272\\nEnergy, release of 147\\nEntoderma Wittrockii 254\\nEnvironment 228\\nEpidermis 61, 85\\nEpiphytes 250\\nEschscholtzia 271, ovules of 201\\nExcretion 147\\nExobasidium, hyphoe of 35\\nFagus sylvatica 254\\nFern 109, 194, 212; leaflet 195\\nFern worts 53\\nFig, inflorescence of 209\\nFilament 202\\nFission 16, 186; algae 6\\nFlax, flower of 207; stem of\\nFlowers 77, 197; leaves 107; of\\nflax 207; of mousetail 208; of\\nmulberry 224; \u00c2\u00b0f raspberry 22 4\\\\\\nof sweet pea 207\\nFly fungus 272\\nFoods 135, 275; of spores 189;\\nstorage of 142; transfer of 142\\nFragmentation 187\\nFraxinus, calyx and pistil of 200\\nFructifications 191\\nFruit 219, 220, 282, 283, 284;\\nfleshy 221; of apple 224; of\\ncherry 223; of wintergreen 223;\\nwinged 281\\nFucus 25, 26, 27", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0308.jp2"}, "309": {"fulltext": "INDEX.\\n305\\nAll references are to pages. Italic figures indicate illustrations.\\nFunaria Americana 4S\\nFunction 1 15\\nFungi 255, 257; fission 9\\nFusion 38\\nGametes 41\\nGametophyte 41; of Bazzania 45;\\nof fernworts 53; of Polytrichum\\n47; reduction of 54\\nGaultheria procumbens 223\\nGelatin 9\\nGeotropism 172; transverse 175\\nGeranium pods 278\\nGerardia, parasitic 258\\nGlceocapsa 6\\nGrasses 175 leaf of 99, 238\\nGrowth 24, 124, 154; conditions\\nof 159; localization of 19; of\\ncell-wall 5; of spores 190; period\\nof 156\\nGymnosperms 198\\nHairs 86, 199, 24O; of nettle 267\\nHalophytes 237, 244\\nHaustoria 36; of Peronospora 38\\nHeat 149\\nHeliotropism 170\\nHellebore, pistil of 200\\nHelotism 255\\nHibiscus, pollen grains of 205\\nHoneysuckle, buds 75; leaf 102\\nHop, stem of 177\\nHosts 34\\nHouseleek 243\\nHydrophytes 246\\nHydrotropism 177; apparatus for\\n178\\nHyphse 30; of Exobasidium 35;\\nof lichen 257; of Trametes 36\\nIberis, stem of 85\\nImpatiens pods 278\\nImpulse, transmission of 164\\nInfection 35\\nInflorescence 74\\nInternodes 83\\nIrregularity 206\\nIrritability 117, 164; localization\\nof 164\\nLand plants 125\\nLarch, shoot of 239\\nLasiagrostis 238\\nLeaves 96; arrangement 98; base\\n99; blade 102; compound 104;\\nfall of 113; foliage 98; form 98;\\nmargin 241 mosaics 170; of\\nmosses 47; sections 109, 111,\\n112, 183, 238; simple 104,\\nspore 195; stalk 101; storage\\n108\\nLichens 39, 257; mycelium of 38\\nLight 141, 160, 232, 247\\nLilium bulbiferum 212\\nLily 212; anther off 03; cell of 3;\\npollen grains of water 205\\nLinden, shoot of 74\\nLiverworts 42, 194, thallose 44\\nLocust, stem of 108\\nLodgers 253\\nLonicera buds 75\\nLotus corniculatus 222\\nLunularia cruciata 43\\nLychnis githago 199\\nMallow, pollen grains of 205\\nMaple, bud of red 75; fruit of 281;\\nNorway 171\\nMarchantia 211\\nMarsilia, root of 61\\nMegaspore of lily 3\\nMelampsora salicina 189\\nMesophytes 231\\nMetabolism 116\\nMicrococcus 10\\nMildew 37\\nMimicry 267\\nMoisture 162, 234\\nMold, black 34\\nMonopodial branching 48\\nMosses 46, 194; brood buds of 211;\\ncapsules 194; gametophyte 193\\nMotor organs 180\\nMougeotia 17\\nMountain ash, chromoplast 4\\nMousetail 208\\nMovements 164; air 232; com-\\nbined 172; contact 178, 182;\\ngrowth 168; light 181 multi-\\ncellular members 168; paratonic", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0309.jp2"}, "310": {"fulltext": "306\\nINDEX.\\nAll references are to pages. Italic figures indicate illustrations.\\n168, 169; photeolic 182; proto-\\nplasm 164; spontaneous 168,\\n181; to reduce illumination 238;\\nturgor 179; water 247\\nMucor 193, Mucedo 32\\nMulberry flower 224\\nMultiple fruits 223\\nMustard 173\\nMutualism 252\\nMycelium 32 of lichen 38\\nMycorhiza 254; of orchids 255\\nMyosurus minimus 208\\nNasturtium 106, 170\\nNepenthes villosa 262\\nNettle 267\\nNitrogen supply 261\\nNodes 83, 241\\nNostoc 7\\nNucleus 3\\nNutation 168\\nNutrition 49, 124; of green plants\\n138\\nNymph aea, pollen grains of 205\\nOat, cell of 4; grain 220\\nOffsets 77, 213\\nOil receptacle 151\\nOleaster, scales of 241\\nOligotrichum aligerum 48\\nOnion stem 89\\nOpuntia vulgaris 240\\nOrchid, chromoplast of 4\\\\ myco-\\nrhiza of 255; pollen mass of 205\\nseeds of 280\\nOrgan 115\\nOrthotrichum 49\\nOscillaria 8\\nOvulary 200\\nOvules 197, 198, 200, 201\\nOxygen 162\\nPalm stem 85\\nPansy seed 219\\nParasites 34, 138\\nParasitism 257\\nParmelia conspersa 257\\nPea, root of 157; seedling 68;\\nshoot of 108\\nPear, prickly 240\\nPenicillium glaucum 191\\nPeperomia trichocarpa 244\\nPerianth 205\\nPericarp 219\\nPeriderm 66, 91\\nPeronospora 38\\nPetiole, scarlet runner 180\\nPhascum cuspidatum 50\\nPhotosynthesis 140, 146; product\\nof 141\\nPhysiology 115\\nPhytolacca decandra 219\\nPilobolus crystallinus 271\\nPimpernell, capsule of 222\\nPine, Scotch 78\\nPistils 200; closed 198; simple and\\ncompound 199\\nPitcher plant 107\\nPith 27, 89; rays 93\\nPlacenta 202\\nPlasmodia 120\\nPlastids 3\\nPlectranthus, hairs of 86\\nPleurococcus 11, 12\\nPokeberry seed 219\\nPollen 203, 204, 205\\nPollination 207, 275 of eel grass\\n274\\nPolygonatum, leaf of 105\\nPolygonum, stipules of 102; vivi-\\nparum SO\\nPoly podium vulgare 54\\nPolyporus 33\\nPolysiphonia 24\\nPolytrichum commune 47\\nPond weed 213\\nPoplar, white 254\\nPoppy, California 271\\nPorella platyphylla 46\\nPotamogeton crispus 213\\nPotassium, salts 141\\nPotato 216; cell of 4; pistil of\\nwhite 200\\nPrecipitation 234\\nProtection 233, 266; of spores and\\nseeds 270\\nProteids 142\\nProtococcus 257\\nProtonema 49", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0310.jp2"}, "311": {"fulltext": "INDEX.\\n307\\nAll references are to pages. Italic figures indicate illustrations.\\nProtoplasm 1, 2, 119; movements\\nof 164; powers of 116\\nPteris 69, 109\\nPyrola chlorantha 221\\nRanunculus aquatilis 162; leaf of\\n99\\nReaction 165\\nRepair 124\\nReproduction 3, 117, 185; sexual\\n186, 218; vegetative 186\\nRespiration 145 intramolecular\\nM7\\nRhizoid 19, 21, 46, 76\\nRhododendron, anther and pollen\\nof 204\\nRiccia sorocarpa 4%\\nRigidity, mechanical 122\\nRings, annual 94\\nRobinia, stem of 108\\nRoots, 59, 62, 70; absorption 128;\\ncage 176; cap 60, 63; climbers\\n250; fleshy 67; float 67; hairs\\n61, 63; hairs and soil 127; of\\nfern 69 pressure 130; tubercles\\n255; woody 66\\nRose, flower of 209; shoot of 101\\nRotation 167\\nRubus idseus 224\\nRunners 77\\nRye, stem of 161\\nSaccharomyces cerevisiae 31\\nSalts, absorbed 138; dissolved 127\\nSalvinia natans 196\\nSaprolegnia lactea 188\\nSaprophytes 137\\nSarcina 10\\nSarracenia purpurea 107; vario-\\nlaris 262\\nSaxifrage 277\\nScales 106, 24I\\nScarlet runner 180\\nScions 214\\nScotch pine 198\\nSedge 267\\nSedum, acre 79; dasphyllum 214;\\nternatum 208\\nSeed 218; coats 219; of orchid\\n280; plants 57; pods, dehiscence\\nof 278\\nSeedlings 97\\nSempervivum tectorum 243\\nSensitive plant, leaf of 183\\nSepals 206\\nShepherd s purse 200\\nShoot 45, 72, 82, 211; of larch\\n239; of linden 74; winter\\n213\\nSnowberry, fruit of 155\\nSocieties 249\\nSoil 126, 235; water 127\\nSpanish needle, fruits of 284\\nSpirogyra 17, 18\\nSplachnum ampullaceum 50; lu-\\nteum 50\\nSpores 41, 185, 188; cases 192,\\n196, 273; chain 191; free 190;\\nleaves 196; non-motile 189\\nSporophyte 41, 193; of fernworts\\n55; of mosses 49; of Phascum\\n50; of Polypodium 54\\nStamens 202 union of 203\\nStarch, reserve 143\\nStele 61, 63, 85, 86, 87, in\\nStem 46, 83, 95; habit 84; sec-\\ntions of 85, 87, 88, 89, 91, 92,\\n94, 122, 161\\nStigma 199\\nStimulation 164\\nStipules 99\\nStolons 77\\nStoma no\\nStonecrop 208, 214\\nStorksbill pods 279\\nStrains 162\\nStrawberry, flower 208; runner\\n215\\nStreaming 167\\nStyle 199\\nSugar cane, node of 241\\nSundew leaves 264\\nSweetbrier rose 209\\nSweet pea, flower of 207\\nSweet violet, anther of 204\\nSymbiosis 252\\nSymphoricarpus 155\\nSympodial, branching 48", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0311.jp2"}, "312": {"fulltext": "308 INDEX.\\nAll references are to pages. Italic figures indicate illustrations.\\nTaraxacum, pollen grains 205\\nTemperature 160, 233, 247\\nTendrils 67, 80, 106\\nTension, due to growth 157; of\\ntissues 121\\nThallus 19, 21, 23, 27; of liver-\\nworts 42, /j$, 4$; of Marchantia\\n211\\nThistle, pollen grains of 205\\nThlaspi, leaf of 102\\nThorns 67, 80, 100, 106; apple,\\nanther of 203; of Vella 81\\nTick trefoil, fruit of 283\\nTococa lancifolia 269\\nTorus 209, 208\\nTouch-me-not, pods of 278\\nTrametes Pini, hyphse of 36\\nTransfer of food 142\\nTranspiration 133, reducing 237\\nTropaeolum 170\\nTubers 79, 244\\nTurgor 1 20; movements 179\\nTwining plants 176, 250\\nUlothrix 19\\nUlva lactuca 23\\nUrtica 267\\nUtricularia, Grafiana 263; vul-\\ngaris, bladder of 264\\nUvularia. leaf of 102\\nVallisneria spiralis 274\\nVanda teres 280\\nVascular bundles 63\\nVaucheria 19, 20\\nVella spinosa 81\\nVenation 104, 105\\nVenus fly-trap 183, 26,\\nVeratrum, pistil of 200\\nViola, anther of 204\\nViolet, capsule 222\\nWater, composition of 248 loss of\\nI 33 2 37; movements of 247;\\nmovement of in plant 129 plants\\n125; solutions in 125\\nWeight, loss of 148\\nWheat, seedling 97; stalk 175\\nWillow, fruit 282; leaf of 105, 189\\nWintergreen, capsule 221; fruit\\n223\\nWood, secondary 91, 92\\nXanthium fruits 284\\nXerophytes 237\\nZoospores 119, 188\\nZygnema 17", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0312.jp2"}, "313": {"fulltext": "", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0313.jp2"}, "314": {"fulltext": "", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0314.jp2"}, "315": {"fulltext": "SCIENCE\\nREFERENCE AND TEXT-BOOKS\\nPUBLISHED BY\\nHENRY HOLT COMPANY, 29 ^Vo^\\nBooks marked are chiefly for refere?ice and supplementary tise, and are\\nto be found in Henry Holt Co. s List of JVorks i?i General Literature.\\nFor further particulars about books not so marked see Henry Holt Co. s\\nDescriptive Educational Catalogue. Excepting James Psychologies,\\nWalker s Political Economies, and Adams Finance, all in the Ameri-\\ncan Science Series, this list contains no works in Philosophy or Economics.\\nPostage on ?iet books 8 per cetit. additional.\\nAmerican Science Series\\nI. Astronomy. By Simon Newcomb, Professor in the Johns Hopkins University,\\nand Edward S. Holden, Director of the Lick Observatory, California.\\nAdvanced Course. 512 pp. 8vo. $2.00 net.\\nThe same. Briefer Course. 352 pp. i2mo. $1.12, net.\\nThe same. Elementary Course. By Edward S. Holden.\\n2. Zoology. By A. S. Packard, Jr., Professor in Brown University. Advanced\\nCourse. 722 pp. 8vo. $2.40 net.\\nThe same. Briefer Course. {Revised and enlarged, 1897.) 338 pp. $1.12 net.\\nThe same. Elementary Course. 290 pp. 12010. 80 cents net.\\n3. Botany. By C. E. Bessey, Professor in the University of Nebraska.\\nAdvanced Course. 611 pp. 8vo. $2.20 net.\\nThe same. Briefer Course. {Entirely new edition, 1896.) 356 pp. $1.12 net.\\n4. The Human Body. By H. Newell Martin, sometime Professor in the Johns\\nHopkins University.\\nAdvanced Course. {Entirely new edition, 1896.) 685 pp. 8vo. $2.50 net.\\nCopies without chapter on Reproduction sent when specially ordered.\\nThe same. Briefer Course. {Entirely new edition revised by Prof. G. Wells\\nFitz, 1898.) 408 pp. i2ino. $1.20 net.\\nThe same. Elementary Course. 261 pp. i2mo. 75 cents net.\\nThe Human Body and the Effect of Narcotics. 261 pp. i2mo. $1.20 net.\\n5. Chemistry. By Ira Remsen, Professor in Johns Hopkins University.\\nAdvanced Course. {Inorganic entirely new edition, 1898.) 850 pp. 8vo.\\n$2.80 net.\\nThe same. Briefer Course. {Entirely new edition, 1893.) 435 PP- $1.12 net.\\nThe same. Elementary Course, \u00e2\u0096\u00a0z jt. pp. i2mo. 80 cents net.\\nLaboratory Manual {to Elementary Course). 196 pp. 12010, 40 cents net.\\nChemical Experiments. By Prof. Remsen and Dr. W. W. Randall. {For\\nBriefer Course.) No blank pages for notes. 158 pp. i2mo. 50 cents net.\\n6. Political Economy. By Francis A. Walker, President Massachusetts Insti-\\ntute of Technology. Advanced Course. 537 pp. 8vo. $2.00 net.\\nThe same. Briefer Course. 415 pp. i2mo. $1.20 net.\\nThe same. Elementary Course. 423 pp. i2mo. $1.00 net.\\n7. General Biology. By Prof. W. T. Sedgwick, of Massachusetts Institute of\\nTechnology, and Prof. E. B. Wilson, of Columbia College. {Revised and\\nenlarged, 1896.) 231 pp. 8vo. $1.75 net.\\n8. Psychology. By William James, Professor in Harvard College. Advanced\\nCourse. 689 704 pp. 8vo. 2 vols. $4.80 net.\\nThe same. Briefer Course. 478 pp. 12010. $1.60 net.\\n9. Physics. By George F. Barker, Professor in the University of Pennsylva-\\nnia. Advanced Course. 902 pp. 8vo. $3.50 net.\\n10. Geology. By Thomas C. Chamberlin and Rollin D. Salisbury, Professors\\nin the University of Chicago. {In Preparation.\\n1 1. Finance. By Henry Carter Adams, Professor in the University of Michi-\\ngan. Advanced Course, xiii 573 PP. 8vo. $3.50 net.\\nV 99 (x)", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0315.jp2"}, "316": {"fulltext": "HENRY HOLT CO. S WORKS ON SCIENCE.\\nAllen s Laboratory Exercises in Elementary Physics. By Charles R.\\nAllen, Instructor in the New Bedford, Mass., High School.\\nPupils Edition x 209 pp. i2mo. 80c, net. Teachers Edi-\\ntion $1.00, net.\\nArthur, Barnes, and Coulter s Handbook of Plant Dissection. By J. C.\\nArthur, Professor in Purdue Univ., C. R. Barnes, Professor\\nin Uinv. of Wisconsin, and John M. Coulter, President of\\nLake Forest University, xi 256 pp. i2mo. $1.20, net.\\nAtkinson s Elementary Botany. By Geo. F. Atkinson, Professor in\\nCornell. For beginners. Fully illustrated. xxiii 441 pp.\\ni2mo. $1.25, net.\\nBarker s Physics. See American Science Series.\\nBarnes Plant Life. By C. R. Barnes, Professor in Uuiversity of\\nChicago. Illustrated, x +428 pp. i2mo. $1.12, net.\\nBeal s Grasses of North America. For Farmers and Students. By\\nProf. W. J. Beal, of Mich. Agricultural College. Copiously\\nIll d. 8vo. Vol. I., 457pp. $2.50, net. Vol. II., 707 pp. $5, net.\\nBessey s Botanies. See American Science Series.\\nBlack and Carter s Natural History Lessons. By Geo. A. Black, and\\nKathleen Carter. (For the very young.) 98 pp. 50c, net.\\nBritton s Manual of the Flora of the Northern States and Canada. By\\nProf. N. L. Britton, Director of N. Y. Botanical Garden.\\nBumpus s Laboratory Course in Invertebrate Zoology. By H. C. Bumpus,\\nProfessor in Brown University. Revised. 157 pp. $1, net.\\nCairns s Quantitative Chemical Analysis. By Fred k A. Cairns. Re-\\nvised and edited by Dr. E. Waller. 417 pp. 8vo. $2, net.\\nChamplin s Young Folks Astronomy. By John D. Champlin, Jr.,\\nEditor of Champlin s Young- Folks Cyclopedias. Illustrated,\\nvi -J- 236 pp. i6mo. 48c, net.\\nCongdon s Qualitative Analysis. By Ernest A. Congdon, Professor\\nin Dtexel Institute. 64 pp. Interleaved. 8vo. 60c, net.\\nCrozier s Dictionary of Botanical Terms. 202 pp. 8vo. $2.40, net.\\nHackel s The True Grasses. Translated from Die natlirlichen\\nPflanzenfamilien by F. Lamson-Scribner and Effie A.\\nSouthworth. v 228 pp. 8vo. $1.50.\\nHall s First Lessons in Experimental Physics. For young beginners,\\nwith quantitative work for pupils and lecture-table experiments\\nfor teachers. By Edwin H. Hall, Assistant Professor in Har-\\nvard College, viii 120 pp. i2mo. 65c, net.\\nHall and Bergen s Text-book of Physics. By Edwin H. Hall, Assist-\\nant Professor of Physics in Harvard College, and Joseph Y.\\nBergen, Jr., Junior Master in the English High School, Bos-\\nton. Greatly enlarged edition. 596 pp. i2mo. $1.25, net.\\nPostage 8% additional on net books. Descriptive list free.", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0316.jp2"}, "317": {"fulltext": "HENRY HOLT CO. S WORK S ON SCIENCE.\\nHertwig s General Principles of Zoology. From the Third Edition or\\nDr. Richard Hertwig s Lekrbuck der Zoologie. Translated and\\nedited by George Wilton Field, Professor in Brown Univer-\\nsity. 226 pp. 8vo. $1.60 net.\\nHowell s Dissection of the Dog. As a Basis for the Study of Physi-\\nology. By W. H. Howell, Professor in the Johns Hopkins\\nUniversity. 100 pp. 8vo. $1.00 net.\\nJackman s Nature Study for the Common Schools. (Arranged by the\\nMonths.) By Wilbur Jackman, of the Cook County Normal\\nSchool, Chicago 111. 448 pp. i2mo. $1.20 net.\\nKerner Oliver s Natural History of Plants. Translated by Prof. F.\\nW. Oliver, of University College, London, ^to. 4 parts.\\nWith over 1000 illustrations and 16 colored plates. $15.00 net.\\nKingsley s Elements of Comparative Zoology. By J. S. Kingsley, Prof,\\nin Tufts College. With abundant laboratory drill. 357 pp\u00e2\u0080\u009e\\ni2mo. $1.20 net.\\nMacalister s Zoology of the Invertebrate and Vertebrate Animals. By\\nAlex. Macalister. Revised by A. S. Packard. 277 pp.\\ni6mo. 80 cents net.\\nMacDougal s Experimental Plant Physiology. On the Basis of Oels\\nPflanzenphysiologische Versuche. By D. T. MacDougal, Uni,\\nversity of Minnesota* vi -f- 88 pp. 8vo. $1.00 net.\\nMacloskie s Elementary Botany. With Students Guide to the Exam-\\nination and Description of Plants. By George Macloskie,\\nD.Sc, LL.D. 373 pp. i2mo. $1.30\\nMcMurrich s Text-book of Invertebrate Morphology. By J. Playfair\\nMcMurrich, M.A., Ph.D., Professor in the University of Cin-\\ncinnati, vii 661 pp. 8vo. New Edition. $3.00 net.\\nMcNab S Botany. Outlines of Morphology, Physiology, and Classi-\\nfication of Plants. By William Ramsay McNab. Revised by\\nProf. C. E. Bessey. 400 pp. i6mo. 80c. net.\\nMartin s The Human Body. See American Science Series.\\n*Merriam s Mammals of the Adirondack Region, Northeastern New\\nYork. With an Introductory Chapter treating of the Location\\nand Boundaries of the Region, its Geological History, Topogra-\\nphy, Climate, General Features, Botany, and Faunal Position.\\nBy Dr. C. Hart Merriam. 316 pp. 8vo. $3.50 net.\\nNewcomb Holden s Astronomies. See American Science Series.\\n*Noel s Buz or, The Life and Adventures of a Honey Bee. By\\nMaurice Noel. 134 pp. i2mo. $1.00.\\nNoyes s Elements of Qualitative Analysis. By Wm. A. Noyes, Pro-\\nfessor in the Rose Polytechnic Institute. 91pp. 8vo. 80c.net.\\nPackard s Entomology for Beginners. For the use of Young Folks,\\nFruit-growers, Farmers, and Gardeners. By A. S. Packard.\\nxvi -f- 367 PP\u00c2\u00ab i2mo. Third Edition, Revised. $1. 40 net.\\nPostage 8 per cent additional on net books. Descriptive list fret.", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0317.jp2"}, "318": {"fulltext": "HENRY HOLT CO. S WORK S ON SCIENCE.\\nPackard s Guide to the Study of Insects, and a Treatise on those\\nInjurious and Beneficial to Crops. For Colleges, Farm-schools,\\nand Agriculturists. By A. S. Packard. With 15 plates and\\n670 wood-cuts. Ninth Edition. 715 pp. 8vo. $4.50 net.\\nOutlines of Comparative Embryology. Illustrated. 243 pp. 8vo.\\n$2.00 net.\\nZoologies. See American Science Series.\\nPeabody s Laboratory Exercises in Anatomy and Physiology. By Jas.\\nEdward Peabody, of the High School for Boys and Girls,\\nNew York. x-)-79pp. Interleaved. i2mo. 60c. net.\\nPerkins s Outlines of Electricity and Magnetism. By Prof. Chas. A\\nPerkins, of the University of Tennessee. 277 pp. i2mo.\\n$1.10 net.\\nPierce s Problems in Elementary Physics. Chiefly numerical. By E.\\nDana Pierce, of the Hotchkiss School. 194 pp. 60c. net.\\nPrice s The Fern Collector s Handbook and Herbarium. By Miss Sadie\\nF. Price. 72 plates, mostly life-size, with guide. 4to. $2.25.\\nRandolph s Laboratory Directions in General Biology. 163 pp. 80c. net.\\nRemsen s Chemistries. See American Science Series.\\nScudder s Butterflies. By S. H. Scudder. 322 pp. i2mo. \u00c2\u00a71.20 net.\\nBrtef Guide to the Commoner Butterflies, xi 206 pp. i2mo.\\n$1.00 net.\\nThe Life of a Butterfly. A Chapter in Natural History for the\\nGeneral Reader. By S. H. Scudder. 186 pp. i6mo. 80c. net.\\nSedgwick and Wilson s Biology. See American Science Series.\\nStep s Plant Life. Popular Papers. Ill d. 218 pp. i2mo. $1.00\\nnet.\\nTorrey s Elementary Studies in Chemistry. By Joseph Torrey, Jr.\\nInstructor in Harvard. 400 pp. i2mo.\\nUnderwood s Our Native Ferns and their Allies. By Lucien M. Under-\\nwood, Professor in DePauw University. 156 pp. i2mo. $1.00\\nnet.\\nWilliams s Elements of Crystallography. By George Huntington\\nWilliams, late Professor in the Johns Hopkins University,\\nx 270 pp. i2mo. Revised and Enlarged. $1.25 net.\\nWilliams s Geological Biology. An Introduction to the Geological\\nHistory of Organisms. By Henry S. Williams, Professor of\\nGeology in Yale College. 8vo. 395 pp. $2.80 net.\\nWoodhull s First Course in Science. By John F. Woodhull, Pro-\\nfessor in the Teachers College, New York City.\\nBook of Experitnents. xiv 79 pp. 8vo. Paper, soc.net,\\nII. Text-Book, xv -f- 133 PP- i2mo. Cloth. 65c. net.\\nIII. Box of Apparatus. $2.00 net (actual cost to the publishers).\\nWoodhull and Van Arsdale s Chemical Experiments. An elementary\\nmanual, largely devoted to the Chemistry of every-day life.\\nInterleaved. 136 pp. i2mo. 60c. net.\\nZimmermann s Botanical Microtechnique. Translated by James Ellis\\nHumphrey, S.C. xii-f-296pp. 8vo. $2.50^.\\nHENRY HOLT CO., 29 West 23D St., New York.", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0318.jp2"}, "319": {"fulltext": "", "height": "3532", "width": "2086", "jp2-path": "outlinesofplantl00barn_0319.jp2"}, "320": {"fulltext": "", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0320.jp2"}, "321": {"fulltext": "", "height": "3565", "width": "2202", "jp2-path": "outlinesofplantl00barn_0321.jp2"}, "322": {"fulltext": "", "height": "3557", "width": "2352", "jp2-path": "outlinesofplantl00barn_0322.jp2"}}