A LABORATORY MANUAL 
 
 ANY 
 
 
 NEW YORK.:- CINCINNATI. : CHIC AGO 
 
 AMERICAN BOOK COMPANY 
 

A LABORATORY MANUAL 
 
 PRACTICAL BOTANY 
 
 BY 
 
 CHARLES H. CLARK, A.M., D.Sc, 
 \\ 
 
 PRINCIPAL, OF WINDSOR HALL SCHOOL 
 
 NEW YORK-:- CINCINNATI-:- CHIC AGO 
 
 AMERICAN BOOK COMPANY 
 
BIOL -Y 
 R 
 G 
 
 COPYKIGHT, 1898, BY 
 
 AMERICAN BOOK COMPANY. 
 
 MAN. PRAC. BOTANY. . 
 W. P. I 
 
CONTENTS. 
 
 INTRODUCTION 
 PRELIMINARY STUDIES 
 
 PAGE 
 
 7 
 14 
 
 I. THE SLIME FUNGI (Myxomycetes) 50 
 
 II. THE DIATOMS (Diatomacece) 54 
 
 III. THE FISSION PLANTS (Schizophytes) .... 59 
 
 Class I. The Blue-Green Slimes (Cyanophycece) . 59 
 
 Class II. The Bacteria (Schizomycetes} ... 63 
 
 IV. THE ALG^E 70 
 
 Class I. The Green Algae (Chlorophycece) . . 71 
 
 Class II. The Brown Algae (Phceophycece) . . 110 
 
 Class III. The Red Algae (Rhodophycece or Floridece} 118 
 
 V. 
 
 VI. 
 
 THE FUNGI 120 
 
 Class I. The Chytridiece 121 
 
 Class II. The Smut Fungi (Ust'daginecc) . . . 122 
 Class III. The Molds and Mildews (Phycomycetes) . 125 
 Class IV. The Sac Fungi (Ascomycetes) . . .136 
 Class V. The Rusts (JEcidiomycetes) . . .157 
 
 Class VI. The Toadstools and their Allies (Basidio- 
 
 mycetes) 
 
 THE BRYOPHYTES 
 
 Class I. The Liverworts (Hepatica*) 
 Class II. The Mosses (Musci) . 
 
 . 160 
 
 . 167 
 
 . 167 
 
 176 
 
6 CONTENTS. 
 
 PAGE 
 
 VII. THE PTERIDOPHYTES 183 
 
 Class I. The True Ferns (Filicince) . . .186 
 Class II. The Horsetails (Equisetince) . . . 200 
 Class III. The Club Mosses (Lycopodince) . . .202 
 
 VIII. THE SPERMAPHYTES 205 
 
 Class I. The Gymnosperms 206 
 
 Subclass I. The Cycads 
 
 Subclass II. The Conifers ..... 
 
 Subclass III. The Joint Firs .... 
 Class II. The Angiosperms 218 
 
 Subclass I. The Monocotyledons . . . 220 
 
 Subclass II. The Dicotyledons . . . .225 
 
 APPENDIX 
 
 THE CULTIVATION OF THE LOWER PLANTS- FOR LABORATORY 
 
 USE 257 
 
 REAGENTS, CULTURE MEDIA, AND STAINING FLUIDS . . 264 
 
 GENERAL INDEX 267 
 
A LABORATORY MANUAL IN PRAC- 
 TICAL BOTANY. 
 
 INTRODUCTION. 
 
 GOOD authorities estimate that there are more than one 
 hundred and fifty thousand species of plants. In the 
 study of this vast number of different forms we need a 
 framework to build on that will give form and substance 
 to our ideas, placing the facts acquired in positions where 
 we shall be able to find and use them. In the following 
 pages the practical studies have been made to take their 
 appropriate places in a brief outline of classification, to the 
 end that the student's knowledge may assume definiteness 
 of form. 
 
 Many and various schemes of classification have been 
 employed, which differ more or less in accordance with 
 the varying ideas of different investigators, and because 
 of the impossibility of agreement as to the position of 
 certain forms. In the case of the Flowerless Plants, the 
 difficulties of classification are especially great. New 
 plants are frequently discovered. New facts come to 
 light about known organisms which sometimes show that 
 forms which have been considered as separate plants are 
 really only different stages in the development of a single 
 plant ; and points that have been considered as fixed in 
 the classification become unsettled. Any classification, 
 especially in the case of the lower groups, must, there- 
 fore, be looked upon as merely provisional, and subject to 
 
 7 
 
8 PRACTICAL BOTANY. 
 
 change as investigations bring to light new knowledge. 
 The development of plant life has not been direct from 
 the simple one-celled plants up to the complicated struc- 
 tures of the highest types, but different lines of develop- 
 ment have been followed, producing puzzling complications 
 when an attempt is made to locate the forms in a classifi- 
 cation. 
 
 To gain a clear and consistent conception of plant life, 
 the logical order of study is from the lowest to the high- 
 est forms. Some teachers of undoubted authority do not, 
 however, consider this to be the best order for begin- 
 ners to meet the subject. The course of which the present 
 exercises form a part contemplates a considerable amount 
 of previous study of the gross morphology of seeds, roots, 
 stems, leaves, flowers, and fruits of the Flowering Plants, 
 with considerable attention to the divisions into groups 
 and classes, and with sufficient attention to analysis to 
 enable the student to find the names of plants. With 
 this preparation it seems to the writer that the student 
 can enter with profit upon a course which will give him a 
 general view of the whole plant world, beginning with 
 plants of the simplest organization. In the lowest forms 
 we come closest to the processes of nature, and, as we 
 advance in the study of the higher orders, our develop- 
 ment in knowledge follows nature in her development of 
 processes. In the lowest forms we study simple masses 
 of protoplasm ; as we go on from one simple plant to 
 another of somewhat higher type, we learn how, under 
 the mysterious laws of nature, the same elementary sub- 
 stances are combined to produce the myriads of Different 
 forms of plant structure. Botany becomes to us some- 
 thing very different from the assorting of various forms 
 and memorizing barbarous Latin and Greek names. The 
 value of the knowledge how to determine the name of a 
 plant by means of a key to the classification should not 
 
INTRODUCTION. 9 
 
 be underrated ; but too much cannot be said against that 
 view of the science which still prevails in many schools, 
 that the sole purpose of the study of botany is to learn 
 the names of plants. 
 
 A point of quite general agreement in the classification 
 of plants, and one that is sufficient for the beginner, is a 
 division into the four groups of ThaUopkytes, or plants 
 which have no true roots, stems, or leaves ; Bryophytes, 
 or Moss plants ; Pteridophytes, or Fern plants ; and Sper- 
 maphytes, or Seed plants. 
 
 The Thallophytes. These plants include a very large 
 number of lowly organized forms. They are distinguished 
 from all the plants above them by the fact that they are 
 either unbranched, or are divided into branches which are 
 just alike in structure ; in other words, they show no 
 differentiation into stem, root, and leaf, though in some 
 plants there is a foreshadowing of such differentiation. 
 The plant body is called a thallus. There is a more or less 
 regular alternation of generations between forms which 
 produce simple spores and forms that produce cells which 
 unite sexually and give rise to a zygospore, or oospore, from 
 which a new plant develops, though in many of the Thal- 
 lophytes this alternation of generations is unknown, or is 
 wanting. The sexual cells are known as gametes; the 
 form of the plant which bears them is the gametophyte. 
 The form of the plant which bears simple spores is known 
 as the sporophyte. This alternation of generations between 
 gametophyte and sporophyte is by no means confined to 
 the Thallophytes. It extends in general throughout the 
 whole vegetable kingdom, and is more highly marked in 
 other groups than it is in the Thallophytes. In the case 
 of the Thallophytes, the form which bears the name is 
 usually the gametophyte, as this is the most highly devel- 
 oped form of the plant. Another fact which distinguishes 
 the Thallophytes is that the female gamete is never an 
 
10 PRACTICAL BOTANY. 
 
 archegonium, while in all the other groups it is essentially 
 an archegonium. The three higher groups are, therefore, 
 sometimes grouped together as archegoniates. The Thal- 
 lophytes, also, in many cases reproduce themselves asexu- 
 ally by cell division, and by the formation of sporelike 
 cells called gonidia, which are distinguished from ordinary 
 spores by the fact that they do not enter into the alterna- 
 tion of generations. Ordinary spores are borne by spo- 
 rophytes, and develop into gametophytes. Gonidia are 
 borne by gametophytes, and develop into gametophytes. 
 
 The Bryophytes. Here also the ordinary form of the 
 plant is the gametophyte. The alternation of genera- 
 tions is well marked. The ordinary Moss plants produce 
 male gametes, antherozoids or spermatozoids, and- female 
 gametes, oo spheres. These unite and produce oo spores, 
 which develop in the archegonium into sporophytes. The 
 sporophyte produces spores, which grow first into small, 
 flat cell aggregates known as protonemce. The protonema 
 throws out lateral, or in some cases terminal, buds, which 
 develop into gametophytes or ordinary Moss plants. There 
 is no reproduction by the formation of gonidia, as in the 
 Thallophytes, but there is a vegetative reproduction by 
 gemmce, which form on various parts of the gametophyte. 
 A differentiation into root, stem, and leaf appears in a 
 rudimentary form. There are no true roots, but uni- 
 cellular or multicellular filaments known as rhizoids per- 
 form the functions of roots. Rudimentary fibrovascular 
 bundles also make their appearance. 
 
 The Pteridophytes. Here, in contrast with the Thallo- 
 phytes and Bryophytes, the ordinary form of the plant is 
 the sporophyte. The alternation of generations is sharp. 
 The spore develops into a flat aggregate of cells called the 
 prothallium, which resembles in function the protonema of 
 the Bryophytes. The prothallium is the gametophyte. 
 It bears in specially differentiated cells antherozoids or 
 
INTRODUCTION. 11 
 
 spermatozoids, the male gametes, which fertilize other 
 specially differentiated cells, the oospheres or female 
 gametes. The oospore, which results from this fertiliza- 
 tion, develops into the sporophyte or ordinary Fern plant. 
 /The differentiation into root, stem, and leaf is well 
 marked, as is also the development of fibrovascular 
 bundles. 
 
 The Spermaphytes. Here also the ordinary form of the 
 plant is the sporophyte. Two kinds of spores are borne, 
 microspores or pollen grains, and macrospores or embryo sacs. 
 Each kind of spore develops into a minute prothallium, 
 and these prothallia represent the gametophyte. The 
 male gamete is either the original nucleated protoplasm 
 of the pollen grain, or is one of the nucleated cells formed 
 by the division of that protoplasm in the formation of the 
 male prothallium in a tube which grows out of the pollen 
 grain. The female gamete is a nucleated cell situated 
 near one end of the female prothallium, which is formed 
 in the embryo sac in the ovary of the pistillate flower. 
 From the fertilization of the female gamete by the male 
 gamete there results a seed which distinguishes this 
 group from the three lower groups. The differentiation 
 into root, stem, and leaf, and the development of the 
 fibrovascular bundles reach their perfection in the Sper- 
 maphytes. 1 
 
 Beyond this grouping of all plants into Thallophytes, 
 
 1 It is not expected that the beginner will gain very definite ideas of 
 the facts which have determined these four great groups from reading 
 the preceding paragraphs. A clear conception of these facts will come 
 only after the actual observation and study of plants which show these 
 distinguishing characteristics. Attention will frequently be called to 
 these points in connection with the practical studies of plants in the fol- 
 lowing pages. Whenever attention is thus directed to the principles 
 which have led to the separation of all plants into these four groups, the 
 pupil should read and reread these paragraphs until he gains a clear con- 
 ception of the principles. 
 
12 PRACTICAL BOTANY. 
 
 Bryophytes, Pteridophytes, and Spermaphytes, there is 
 less agreement among the authorities. Different princi- 
 ples have governed the separation into subdivisions. The 
 terms group, branch, class, order, and family are variously 
 and arbitrarily used by writers, and a comparison of the 
 schemes of classification of different authorities usually 
 leads to confusion of ideas. In the writer's judgment 
 too much stress should not be laid on classification in the 
 case of the beginner, and the minutiae of classification 
 should be wholly omitted. At the same time some out- 
 line of classification seems an absolute necessity to aid the 
 student in arranging the facts he acquires. 
 
 The scheme of classification which forms the framework 
 for the following pages is, with some slight modifications, 
 that given by Goebel in his " Outlines of Classification 
 and Special Morphology of Plants." Its main features 
 are presented in the tabular view. 
 
THE FLOWERING PLANTS. 15 
 
 THE FLOWERING PLANTS. 
 The Dicotyledonous Angiosperms. 
 
 / 1. Soak seeds of the Bean, Pea, Squash, Mustard, Buck- 
 wheat, and Flax in water over night. Then cover them 
 half an inch deep in sawdust kept moist, not drenching 
 wet, and in a warm, light place, until they germinate 
 and grow into little plants from one to three or four 
 inches high. Other seedlings of these plants may be 
 grown in moist earth. If the earth has been previously 
 baked, growths of weeds will give less trouble. It is a 
 good plan to make several plantings, at intervals of a few 
 days, to secure plants at various stages of development. 
 
 2. Make examinations of the little plants from the 
 time the seed coats, or outer coverings of the seeds, begin 
 to split open until the plants have attained considerable 
 size. Represent them by outline drawings in the different 
 stages of development. Do the seed coats all split open 
 in the same way ? What becomes of the seed coat ? Of 
 how many parts does the portion within the seed coat con- 
 sist ? Do these parts the cotyledons remain under- 
 ground, or are they raised above its surface ? Do you find 
 any evidence that a plant does work? Are the cotyle- 
 dons of seeds generally raised above ground ? How many 
 instances do you know of in which they are not ? The 
 portion of the stem that holds the cotyledons above ground 
 is the hypocotyl. The cotyledons are modified leaves ; 
 they are storehouses of nourishment for the first growth 
 of the plant. Does the rapidity of the first growth appear 
 to depend upon the amount of nourishment stored up in 
 the cotyledons ? Watch the cotyledons as the plants 
 become older ; do they develop ? If not, what does be- 
 come of them ? Plants in which the cotyledons expand 
 equally in the first growth are called Dicotyledons. 
 
16 
 
 PRELIMINARY STUDIES. 
 
 3. Examine large Beans and Peas, some dry and some 
 that have been soaked over night. On the outside of the 
 testa, or seed coat, notice the scar hilum where the seed 
 was attached, and near it a small opening, the micropyle. 
 Use a magnifying glass to see the micropyle. Split the 
 seeds. Near the hilum, and lying between the two coty- 
 ledons, find a 
 miniature plant. 
 At one end of 
 this is the radi- 
 cle, a small 
 pointed organ. 
 Connected with 
 the radicle is a 
 delicate struc- 
 ture which a 
 good magnify- 
 ing glass w r ill 
 show to be com- 
 posed of mi- 
 nute beginnings 
 of leaves, the 
 plumule. Exam- 
 ine also for these 
 structures Peas 
 and Beans that 
 have been ger- 
 minating from 
 
 one to five days. How are the radicle and plumule located 
 in the seeds with reference to the hilum and micropyle ? 
 The use of the micropyle will be considered later. 
 
 4. The cotyledons and the plumule and radicle with 
 the minute hypocotyl constitute the embryo. In the Bean 
 and the Pea, the stores of food that are to serve the plant 
 in the beginning of its growth, are in the cotyledons. 
 
 FIG. 1. Section through a cotyledon of a Bean, 
 showing starch and aleurone granules in the cells. 
 Starch and aleurone are the nutrient materials 
 stored up for the future growth of the plant. 
 When the seed germinates, these substances are 
 converted into sugar, which is the form in which 
 the food passes from one part of the plant to an- 
 other. (X35.) 
 
THE FLOWERING PLANTS. 17 
 
 This is not always the case ; a considerable variety of 
 arrangements occur. Using seeds of common plants, 
 soaking them over night, cut through so as to show the 
 location of the embryo, which will sometimes be found 
 imbedded in the stored-up food, and sometimes situated so 
 as to inclose it. When the stored-up food is not in the 
 cotyledons, it is known as albumen or endosperm. Seeds 
 containing it are albuminous ; those not containing it are 
 exalbuminous. Draw all the different types found. Dis- 
 sect out some of the embryos whole. Seeds of Four- 
 o'clock, Poppy, Barberry, Asparagus, Locust, Spring 
 Beauty, and numerous other plants will serve for these 
 observations. 
 
 5. Trace the development of the radicle in seedlings 
 of different ages. What is the direction of its growth? 
 Place on their sides seedlings that have well-developed 
 radicles, covered in moist sawdust, so that their radicles 
 and plumules point horizontally. In twenty-four hours 
 examine. The radicles have obeyed an influence which 
 has turned them towards the center of the earth. This 
 influence is believed to be the attraction of gravitation ; 
 its manifestation is called geotropism, and the movement 
 is a geotropic movement. 
 
 6. As the radicles grow, do they branch ? If so, is 
 there any uniformity in the mode of branching ? Do any 
 of the radicles develop into a taproot, i.e., a root that 
 grows straight towards the center of the earth ? If there 
 is a taproot, where do the secondary roots, i.e., those that 
 form after the primary root has become well started, have 
 their origin ? 
 
 7. Near the tip ends of the youngest roots find with a 
 magnifying glass minute hairs. Do they cover the tip of 
 the root ? If not, about how far from the tip do you find 
 them ? As the roots increase in age, the hairs die away, 
 and new ones are formed on the newer portions of the root. 
 
 CLARK'S EOT. 2 
 
18 PRELIMINARY STUDIES. 
 
 These hairs are of the utmost importance in the economy 
 of the plant. They are the principal organs of absorption 
 for the nutrient fluids of the plant. The fluids enter them 
 from the soil by the physical process of osmosis. These 
 fluids contain the dissolved mineral and organic matters 
 which furnish food for the plant. They pass from cell to 
 cell up to the very tops of the loftiest trees. It is known 
 that osmotic action has much to do with this passage of 
 the fluid, but it is still an unsolved problem why the 
 osmosis should be so much stronger from without inward 
 than it is from within the plant outward. Because it is 
 stronger from without, there results a pressure, known as 
 root pressure, which carries the fluids up into the plant 
 and keeps up a supply of food. 
 
 8. Trace the development of the plumule. When the 
 seedling was placed in the horizontal position in Number 
 5, the plumule soon turned upward from the earth. The 
 movement is called an apogeotropic movement. 
 
 9. Place a well-developed seedling- in a position where 
 it will receive the light on only one side. Notice that 
 after some time it turns its leaves towards the light, or 
 exhibits heliotropism. 
 
 10. Observe the arrangement of the leaves on the young 
 stems. Is the arrangement the same in all of these plants ? 
 Describe the leaf arrangements you find, whether the 
 leaves are opposite one another, or are arranged alter- 
 nately. If opposite, consider the positions of successive 
 pairs. If alternate, count the number of leaves in one 
 complete revolution about the stem. 
 
 Are the leaves first produced by the seedlings of the 
 same shape as those formed after the plants have attained 
 considerable size ? If not, describe the differences for 
 each plant and illustrate by outline drawings. Are the 
 lower leaves in all cases as well developed as those formed 
 later ? As we shall consider more fully later, a large part 
 
( 
 THE FLOWERING PLANTS. 19 
 
 of the food of the plant enters through the leaves. If you 
 find that some of the lower leaves are not so well devel- 
 oped as the later ones, consider the cotyledons and see if 
 you can give any reason for the difference. 
 
 11. Draw one of the latest formed leaves of each seed- 
 ling, showing the venation, or arrangement of the veins, 
 in each. Are the leaves netted-veined, i.e., do the veins 
 form interlacing network, or are they parallel-veined, 
 i.e., do the veins run parallel, or nearly parallel, to one 
 another ? Netted- veined leaves are characteristic of the 
 Dicotyledons. Parallel-veined leaves are, in general, 
 characteristic of the Monocotyledons. 
 
 12. Consider the shapes of the different leaves. Find, 
 by consulting the figures and descriptions in Gray's 
 "Manual of Botany," what names are applied to the 
 different shapes. Also consider the edges of the leaves 
 and find what names are used to designate them. 
 
 13. Examine the venation, shape, and edges of the 
 leaves of a number of common plants, e.g., House Gera- 
 nium (Pelargonium), Wild Geranium, India Rubber Plant, 
 Willow, Maple, Horse-chestnut, Birch, Apple, Beech, 
 Elder, Oak, Cherry,. Lilac, Currant, Loosestrife, Begonia, 
 etc. Find names to describe the shapes and edges of each. 
 Twigs of many of the common trees will put forth their 
 leaves even in midwinter, if they are placed with their cut 
 ends in water in warm places. 
 
 14. Examine the vernation of the leaves of the plants 
 mentioned in Number 13 and of other similar plants. 
 Vernation is the name applied to the arrangement of the 
 undeveloped leaf in the bud. Dissect some of the buds, 
 cut some transversely, some longitudinally, examine with a 
 magnifying glass, and consult Gray's " Manual of Botany" 
 for the names given to the different shapes found. This 
 study should be made on buds just ready to open in the 
 spring or on those forced to open. 
 
20 PRELIMINARY STUDIES. 
 
 15. Examine the arrangement of the leaves on the 
 plants mentioned in Number 13. The points on the stem 
 where the leaves originate are called nodes; the spaces 
 between the nodes are internodes. On these or on other 
 plants find cases where the arrangement is opposite, i.e., 
 two at each node, one opposite the other; cases where 
 the arrangement is alternate, i.e., only one at each node ; 
 other cases where the leaves are in whorls, i.e., several at 
 each node, arranged around the stem. Examine as many 
 common house and outdoor plants as possible. The posi- 
 tion of the leaves of the previous summer may be seen on 
 the winter stem by the leaf scars, one at the base of each 
 bud that has formed for the following season. What 
 arrangement do you find to be the most common? 
 
 16. Select twigs on which the leaves are arranged alter- 
 nately. Starting with any leaf, wind a string around the 
 twig so as to pass by the base of each leaf. Determine 
 whether the number of leaves passed in each revolution 
 about the stem is constant. Do you find the arrangement 
 the same in all the plants examined ? State what number 
 of leaves you find in one revolution about the stem in 
 each different case. Select a straight stem, and with a 
 knife cut a line vertically down from the base of each 
 leaf found in one revolution about the stem. What por- 
 tion of the circumference of the stem lies between each 
 two consecutive leaves ? Is this fraction the same in all 
 cases examined? The arrangement of the leaves on the 
 stem is called phyllotaxy. 
 
 17. Consider the parts of a typical leaf, as of the Straw- 
 berry, Wild Geranium, House Geranium, Rose, Red Clover, 
 Apple, etc. The broad, expanded portion is the blade or 
 lamina ; the stem supporting the blade is the petiole or leaf 
 stalk; at the base of the petiole are the stipules. Find 
 leaves that have no petioles ; such leaves are said to be 
 sessile. Find leaves that have no stipules. Find cases 
 
THE FLOWERING PLANTS. 21 
 
 in which the stipules have developed into spines. Find 
 cases in which the stipules are united and perhaps encase 
 the petiole to some extent. 
 
 18. Tear off small bits of the epidermis from the upper 
 and under sides of a leaf, the Lilac leaf, for instance. 
 l j lace it on a microscope slide in a drop of water, outside 
 surface uppermost, and place a cover glass over it. Ex- 
 amine with the low power of the compound microscope 
 for stomata, or minute openings into the interior of the 
 leaf. Each stoma is inclosed by 
 special cells, the guard cells. The 
 stomata are very important organs. 
 The little cells between which the 
 openings pass open and close under 
 the changes of moisture contained in 
 the plant and under the influence of 
 light. They control the transpiration 
 of the water from the plants. Trans- 
 piration is the name given to the 
 passing of the water out of the plant 
 into the air ; it is more than simple FIG. 2. stomata of Lilac 
 evaporation, for its amount depends 
 
 upon the pressure of the fluids within. Root pressure 
 and the control of the transpiration by the stomata regu- 
 late the supply of food materials brought up from the 
 soil by the sap, according to the necessities of the plant. 
 
 On which side of the leaf do you find stomata more 
 abundant ? Make similar studies of the stomata of other 
 leaves. Draw portions of several specimens, showing the 
 stomata and the superficial cells of the epidermis. Are 
 the stomata invariably more abundant on either the upper 
 or under side of the leaf ? If so, on which side ? 
 
 Examine some of the stomata under high power. Draw, 
 showing stomata and epidermal cells. 
 
 Through the epidermis of the leaf, mainly that on the 
 
22 PRELIMINARY STUDIES. 
 
 upper side, there is an exchange of gases by osmosis. 
 Oxygen, which is given off by the plants as a waste prod- 
 uct, passes out ; carbon dioxide from the air, which is a 
 food for the plant, passes in. More than one half of the 
 solid matter of plants is carbon derived from this source. 
 
 19. Tear off bits of the epidermis from the upper and 
 under surfaces of the leaf of the White Water Lily 
 (Nymphcea odorata) and the Yellow Water Lily (Nuphar 
 advena) and examine for stomata. Draw. On which 
 side of the leaf are they the more abundant? Make 
 such explanation as you can of what you find. 
 
 20. Examine stomata obtained from around the edges 
 of the leaf of the Nasturtium (TropcBolum majus). A 
 peculiar form of stoma is illustrated by this observation, 
 the water stoma. Such stomata occur in a comparatively 
 small number of plants. They take their name from the 
 fact that they excrete water in drops. 
 
 21. Using material similar to that mentioned in Num- 
 ber 13, observe the buds growing in the axils of the 
 leaves, i.e., just above the point of attachment of the 
 petiole with the stem. Some of these buds will develop 
 into leafy branches, some simply into leaves, some into 
 flowers, and many will not develop at all. 
 
 Sometimes several buds grow in the axil of the same 
 leaf. These are called accessory or supernumerary buds. 
 Examine branches of Red Maple or Walnut for such buds. 
 
 Adventitious buds are those that form at other places 
 than at the ends of branches or in the axils of leaves. 
 The Willow is perhaps the best plant on which to study 
 them. Twigs from Willow hedges or trees that have 
 been kept cut back are sure to show them. 
 
 Terminal buds are those that form at the ends of 
 branches. 
 
 22. Consider the structure of flowers. The Star 
 Flower (Trientalis Americana)^ May Apple (Podophyllum 
 
THE FLOWERING PLANTS. 23 
 
 peltatum), Spring Beauty (Claytonia Virginica), Wood 
 Sorrel (Oxalis acetosella), St. John's Wort (Hypericum 
 perforatum), Wild Geranium (Geranium maculatum), 
 some varieties of the House Geranium (Pelargonium), 
 or any other wild or cultivated flower, selected by the 
 teacher, may be used in this study. Consult Gray's 
 "School and Field Botany," pp. 79-104, for the plan of 
 a typical flower and the names of the various parts. 
 
 Find in the flower studied and represent by outline 
 drawings a sepal, petal, stamen, pistil, torus. The sepals 
 constitute the calyx; the petals, the corolla. On the 
 drawing of the stamen, letter to show the filament, anther, 
 and the dehiscence of the anther, i.e., the manner in which 
 it splits open to discharge the pollen. Examine under 
 the high power of the compound microscope as many 
 different kinds of pollen as you find. See Gra} r 's " School 
 and Field Botany," Figs. 309-318. On the drawing of 
 the pistil, letter to show the ovary, style, and stigma. Cut 
 open the ovaries of several different flowers, both trans- 
 versely and longitudinally. Study them under a mag- 
 nifying glass and represent both sections in drawings, 
 making the ovules as distinct as possible. Also draw an 
 entire flower, showing all the parts as distinctly as possi- 
 ble, labeling each. 
 
 A flower that has both stamens and pistils is a perfect 
 or hermaphrodite flower; one that has all the parts is a 
 complete flower. Many flowers are incomplete. Some lack 
 either sepals or petals ; others lack both, and are said to 
 be naked. Flowers that have stamens, but no pistils, are 
 staminate ; those having pistils, are pistillate. When both 
 staminate and pistillate flowers are borne on the same 
 plant, it is monoecious; when the staminate flowers are 
 borne on one plant and the pistillate on another, the plants 
 are dioecious. Other plants are polygamous, i.e., some of 
 the flowers are perfect, some pistillate, some staminate. 
 
24 
 
 PRELIMINARY STUDIES. 
 
 In a typical complete flower each of the parts is sepa- 
 rate, all being inserted on the torus. The greatest variety 
 of variations from this type occur. The pistils are fre- 
 quently united through the whole or a part of their 
 length; so also the stamens. If the petals are separate, 
 
 the flower is polypetalous ; if 
 united, as in the Mayflower, 
 Blueberry, and Rhodora, the 
 flower is gamopetalous. If the 
 sepals are separate, the flower 
 is polysepalous ; if united, as in 
 Ground Ivy, Locust, Carnation, 
 Bouncing Bet, Toad Flax, the 
 flower is gamosepalous. Some 
 flowers are both gamopetalous 
 and gamosepalous, as the Bluet, 
 Partridge Vine, Harebell, Twin 
 Flower, and Fringed Gentian. 
 
 23. The .fertilization of the 
 flower. Before the flower can 
 perform the function for which 
 it was designed, namely, pro- 
 duce seed, it must be fertilized. 
 Pollen grains from the same or 
 different flowers are brought in 
 contact with the stigma. Here 
 they begin to grow and send 
 down long tubes through the 
 style to the ovaries. The con- 
 tents of the pollen grains pass 
 down through these tubes and enter certain cells in the 
 ovaries. These cells, the ovules, then develop into seeds. 
 The micropyle, already observed on the Bean and Pea, 
 marks the place where the pollen tube entered the ovule. 
 Even when flowers have both stamens and pistils, self 
 
 FIG. 3. Diagram of a longitu- 
 dinal section of an ovary 
 having only one ovule with 
 basal placentation, designed 
 to exhibit the course of the 
 pollen tube from the stigma 
 to the summit of the embry- 
 onal sac above the ob'sphere. 
 The ovule is anatropous, and 
 is inserted, as is usually the 
 case in Composite. (Luers- 
 sen.) 
 
THE FLOWERING PLANTS. 25 
 
 fertilization, i.e., fertilization of the ovary by pollen pro- 
 duced in an anther on the same flower, is the exception. 
 Cross fertilization, or fertilization by pollen borne on some 
 other plant of the same or a closely related species, is 
 the rule. Self fertilization tends to deterioration ; cross 
 fertilization tends to produce stronger and healthier plants. 
 To effect cross fertilization the pollen is carried by the 
 wind, by insects, and in some cases by birds. As a rule 
 plants that do not bear colored flowers are fertilized 
 by the wind, or are anemophilous ; those that bear col- 
 ored or conspicuous flowers are entomophilous, i.e., are 
 fertilized by insects or birds. The colors, fragrance, and 
 honey in flowers are contrivances of nature to attract 
 insects, which carry the pollen from one flower to another 
 as they search for their food. Not only do we owe the 
 beautiful colors and sweet odors of flowers to this neces- 
 sity of receiving pollen from other plants, but nature has 
 caused the parts of flowers to assume a great variety of 
 curious and interesting shapes to adapt them to receive 
 visits from insects that can benefit them by depositing 
 the pollen in the right place, and to shut out other insects 
 that might rob them of their honey without rendering 
 them service in turn. It is interesting to notice, also, 
 that parallel with these modifications in the shapes of the 
 flowers, there have resulted corresponding modifications 
 in the structure of insects. Certain insects and certain 
 flowers may almost be said to exist for mutual benefit. 
 This subject opens most extensive fields for intensely 
 interesting study. The present limits allow mere men- 
 tion to be made of it. In the season of the flowers 
 take every opportunity to watch insects visiting flowers. 
 Write out an account of what you observe. 1 
 
 1 See Darwin's "Self and Cross Fertilization of Flowers" ; Sir John 
 Lubbock's "Flowers, Fruits, and Leaves"; and Weed's "Ten New 
 England Blossoms and Their Insect Visitors." 
 
26 
 
 PRELIMINARY STUDIES. 
 
 FIG. 4. Transverse section of stem of a 
 Burdock. (X 35.) 
 
 24. The fruit and seed. The entire ovary, together 
 with such parts of the flower as become united with it, 
 
 develops into the fruit. 
 Each ovule develops into 
 a seed, which is the end 
 for which the plant ex- 
 ists. For the study of 
 the different kinds of 
 fruits and seeds, consult 
 Gray's " School and Field 
 Botany," pp. 117-128. 
 
 25. The stem. Make 
 an examination of the 
 general construction of 
 the stems of the Elder, 
 Willow, Maple, Castor- 
 oil Plant, House Geranium, Burdock, etc. With a sharp 
 knife cut across the stems near their tips. Moisten the cut 
 ends, and examine their 
 structure under a mag- 
 nifying glass. At the 
 center is pith ; in some 
 stems of rapid growth 
 the pith has parted and 
 the stem is hollow. Out- 
 side of the pith is a ring 
 of wood, and outside of 
 the wood is the bark. 
 
 Cut through stems 
 of trees where they are 
 of considerable size. 
 Use a magnifier, and 
 observe several rings 
 of wood in place of the single ring in the young shoot. 
 In general one ring of wood is formed each year. 
 
 FIG. 5. Part of transverse section of pres- 
 ent year's growth of stem of Basswood. 
 (X 35.) 
 
THE FLOWERING FLAMS. 
 
 27 
 
 Examine prepared microscope slides of the above or 
 similar plants under the low power of the compound 
 microscope. Also, if possible, examine a number of 
 photomicrographs of sections of the same plants. (See 
 igs. 4, 5, and 6.) The arrangement of the wood in 
 complete circles about a centrally situated pith or in 
 bundles placed in a circle is characteristic of the Di- 
 cotyledonous Angio- 
 sperms. 
 
 26. The root. Cut 
 across the root of the 
 common Burdock. 
 Compare its structure 
 in cross section with 
 the structure of the 
 stem of the same plant. 
 Are the bundles of 
 
 woody fibers situated the same as in the stem ? The 
 arrangement here observed is the rule for roots of this 
 class. 
 
 27. When the trunk of a tree divides and subdivides 
 until it is lost in the branches, it is said to be deliquescent. 
 When the trunk rises straight up as one shaft, the tree is 
 said to be excurrent. Make a list of all the deciduous 
 trees with which you are acquainted, dividing them into 
 deliquescent and excurrent trees. 
 
 FIG. 6. Part of transverse section of 
 stem of Mimulus ring ens. (X 35.) 
 
 The Monocotyledonous Angiospenns. 
 
 1. Raise seedlings of Indian Corn, Oats, Wheat, and 
 Canary Grass in moist sawdust and in earth. Observe 
 that one leaf only shows itself at first, and is followed 
 later by a second. From this characteristic the Mono- 
 cotyledons are named. Continue this observation until 
 the seedlings have attained considerable 
 
 OK THK 
 
PRELIMINARY STUDIES. 
 
 2. Remove a plant of each kind from the earth. Wash 
 the roots and examine them. Do any of these plants have 
 taproots ? Examine the roots of full-grown specimens 
 of these plants as they grow in the field if possible ; if 
 that is not possible, those that have been preserved entire. 
 Do any of these plants have roots that originate above the 
 ground ? Do these roots serve any purpose other than 
 the usual one of supplying nourishment to the plant ? 
 
 Examine the 
 youngest roots 
 of the seedlings 
 for root hairs. 
 
 3. Cut across 
 the stems of 
 Indian Corn, 
 different Lilies, 
 Palm, Canna, 
 and Asparagus. 
 Examine the cut 
 ends with a mag- 
 nify ing glass. 
 Notice that the 
 bundles of the 
 woody fibers are 
 scattered more 
 or less irregularly through the stem. This is, in general, 
 characteristic of the Monocotyledons, or Endogens. 
 
 With a razor or scalpel make thin, transverse sections. 
 Do not try to get complete sections across the stem. Small 
 pieces will do, but they must be very thin. Mount in 
 water, cover with a cover glass, and examine under both 
 low and high powers of the compound microscope, and 
 compare with Figs. 7 and 8. Make also thin longitudinal 
 sections of the Corn, and examine them for vessels whose 
 walls are pitted ; also for vessels whose walls are composed 
 
 FIG. 7. Transverse section through upper part of a 
 Cornstalk, as seen under low power. (X 35.) 
 
THE FLOWERING PLANTS. 
 
 29 
 
 of fibers wound in spi- 
 rals ; also for vessels 
 whose walls are sup- 
 ported by rings at in- 
 tervals. With a little 
 patience all of these 
 vessels may be found. 
 These vessels constitute 
 the principal portions of 
 the wood of the stem. 
 The markings observed 
 are thickenings to give 
 strength to the cell walls 
 and to the stem. 
 
 FIG. 9. Epidermal cells 
 and storaata of Corn. 
 
 FIG. 8. Fibrovascular bundle of Indian 
 Corn, Zea mays. Transverse section, as 
 seen under high power. O, P t P, cells 
 of the ground parenchyma. The tissue 
 represented by thick dark walled cells is 
 the bundle sheath ; E, E, pitted vessels ; 
 F, an annular vessel; A, spiral vessel: 
 L, empty space produced by the tearing 
 apart of the tissues in consequence of 
 rapid growl h ; H, II, sieve tissue consti- 
 tuting the bast or phloem portions of the 
 bundle ; E, E, A, and F are the main ves- 
 sels of the xylem. The lower part of the 
 figure was situated towards the center of 
 the stem. (X 500.) 
 
 4. Examine the veining in the 
 leaves of Corn, Lilies, Palms, 
 Canna, Orchids, Wandering Jew 
 (Tradescantia), and various 
 grasses. Represent by drawings 
 as many types of parallel veining 
 veins are characteristic of the 
 
 as you find. Parallel 
 Monocotyledons. 
 
 5. Examine under the compound microscope bits of the 
 epidermis from both surfaces of each of the above leaves for 
 stomata. On which side of the leaf are they more abun- 
 
30 
 
 PRELIMINARY STUDIES. 
 
 dant ? Represent by drawings as many different types of 
 stomata as you find. Each figure should show a number 
 of the superficial cells of the epidermis and the position of 
 the stomata with reference to these cells. 
 
 6. Study the 'flowers of the Indian Corn. The male 
 flowers are borne in spikes at the very top of the plant. 
 They constitute the tassel. The female flowers are borne 
 lower down. Each filament of silk is the style of a flower. 
 When pollen grains are brought in contact with the stig- 
 mas at the ends of these styles, they send minute tubes 
 the entire lengths of the filaments into the ovules at their 
 bases. The fertilized ovules mature into the seeds 
 kernels of Corn. The fruit is the entire ear of Corn with 
 the husks. 
 
 Is Corn anemophilous or entomophilous? Are its flowers 
 
 perfect? Complete? Is the plant monoecious or dioecious? 
 
 1. Study the flower of any Lily that is available. The 
 
 Trillium, Wild Orange-Red Lily, and the Tiger Lily 
 
 are good. Is the flower 
 perfect ? Is it complete ? 
 Is it regular, i.e., are 
 all the organs in each 
 set of parts of the same 
 shape and size ? Is it 
 symmetrical, i.e., are the 
 numbers of each set of 
 organs the same ? Draw 
 as many of the follow- 
 ing parts as you find : 
 a sepal, petal, a pistil 
 showing ovary, style, and 
 stigma, a stamen show- 
 ing filament, anther, and dehiscence of anther. Show by a 
 figure a cross section and a longitudinal section of the 
 ovary. (See Fig. 10.) Is the flower you are studying 
 
 FIG. 10. Transverse section of ovary 
 of Orange-Red Lily. (X 35.) 
 
TIIK FLOWERING PLANTS. 31 
 
 adapted to fertilization by the wind or by insects? Give 
 reasons for your answer. 
 
 8. Examine the flowers of as many Orchids as possible. 
 State for each one whether it is perfect, complete, regular, 
 symmetrical, or not. Any extended study of the Orchids 
 is too difficult for beginners. The great variety in colors 
 and shapes among the Orchids is believed to be the result 
 of variations to adapt the flowers to fertilization by par- 
 ticular insects, and to protect them from other insects that 
 would rob them of their honey, without rendering any 
 compensating service in the way of depositing pollen of 
 other Orchids on their stigmas. 
 
 The Gymnosperms. 
 
 1. Examine various Pine and Spruce trees as they grow, 
 selecting both old and young trees for study. Are these 
 trees excurrent or deliquescent? Is the arrangement of 
 the branches alternate, opposite, or in whorls? Make 
 lists of all the evergreen trees with which you are ac- 
 quainted, stating whether they are deliquescent or excur- 
 rent, and what the arrangement of the branches is. 
 
 2. Draw diagrams to represent accurately the lengths 
 of the needles, or leaves, of as many different kinds of 
 Pines and Spruces as you can find ; also another set of 
 diagrams to represent in outline these leaves as seen in 
 cross section. Count the number of leaves in each little 
 bundle for each different kind of Pine. Is the number 
 the same in all the bundles of a given species? Does the 
 number differ in different species? Would the number 
 of leaves in the bundles help to determine the species 
 of the Pine ? Describe any difference you may notice in 
 the color and surface of the leaves of different species of 
 Pine. 
 
 Describe the arrangement of the leaves on the branch 
 
32 PRELIMINARY STUDIES. 
 
 of the Spruce. Is the arrangement the same on all the 
 different kinds of Spruce you can find ? Would the 
 arrangement of the leaves help to distinguish the different 
 kinds of Spruce trees? 
 
 Consulting Gray's " Manual of Botany," determine the 
 names of all the different kinds of Pine and Spruce trees 
 you can find. 
 
 3. With a hand lens notice the rows of stomata run- 
 ning lengthwise of the leaves. What purpose do stomata 
 serve ? Tear off bits of the epidermis and examine the 
 stomata under the compound microscope. Draw them 
 as seen under both low and high powers. 
 
 4. In May or early June find Pine trees bearing little 
 cones clustered about the base of the new growth at the 
 ends of the branches. These are the staminate or male 
 flowers. Continue to watch these flowers until they shed 
 their pollen. Observe in what profusion it is produced, 
 and how it is carried by the wind to long distances. 
 Why is it necessary that anemophilous flowers should 
 bear such an abundance of pollen ? Examine the stamens 
 of which the male flower is composed under a magnifier 
 and under the low power of the compound microscope. 
 Find the pollen sacs. Are they borne on the upper or 
 under side of the stamen ? How do they open ? Draw 
 a stamen, showing the pollen sacs and their dehiscence. 
 Examine some of the pollen grains under both low and 
 high powers. Draw one. 
 
 5. Also in May or June find small pinkish cones near 
 the tips of the new growth at the ends of the branches. 
 Dissect one of these cones, noticing that it is made up 
 of very thin leaves and of thicker ones that bear naked 
 ovules. After the ovules have been fertilized, the leaves 
 composing the cone shut together and protect the fer- 
 tilized ovule while it is developing into the seed. 
 
 Are the ovules in the Angiosperms naked? The word 
 
THE FLOWERING PLANTS. 
 
 33 
 
 FIG. 11. Transverse section of stem 
 of Scotch Fir at close of second 
 year's growth. (X 35.) 
 
 Angiosperm, roughly trans- 
 lated, means seed in a ves- 
 sel. Gymnosperm means 
 naked seed. 
 
 The thick leaves that bear 
 the ovules are called the 
 carpels. Where on them 
 are the ovules borne? Is 
 the shape of the pistillate 
 flower adapted to catch pol- 
 len that is being borne 
 about by the wind? Do 
 you think that either the 
 staminate or pistillate flower 
 would attract insects because of its color or odor ? 
 
 The fertilized ovules mature into seeds in the autumn 
 of the second year. Secure some of the ripened cones 
 
 before the seeds have 
 dropped out. Draw one 
 of the seeds. What do 
 you think is the use of 
 the winglike appendage 
 on the seed? 
 
 6. Cut across a Pine 
 shoot of the present sea- 
 son's growth. If the 
 material has been in al- 
 cohol long enough to 
 dissolve out the pitch, 
 it will be pleasanter to 
 
 FIG. 12. - Part of transverse section of stem handle. Compare the 
 of White Pine during second year's arrangement of the pith, 
 growth. (X 35.) A, pith; B, wood of 
 first year's growth ; C, wood of the sec- 
 
 B 
 
 wood, and bark with 
 
 ond year in process of formation ; D, the the stem of an AnglO- 
 
 cambium layer where the new growth 
 
 originates ; E, the bark ; F, pitch ducts, sperm. Counting the 
 
 CLARK'S BOX. 3 
 
34 
 
 PRELIMINARY STUDIES. 
 
 new growth as one, count back five internodes of the 
 stem. Make a transverse section of the fifth internode. 
 Count the number of annual layers of wood. Repeat 
 with other internodes. How do the numbers of annual 
 layers compare with the numbers representing the inter- 
 nodes? How could you tell the age of a given part of a 
 Pine branch without cutting it ? 
 
 7. Examine prepared microscope slides and photo- 
 micrographs of cross sections of Pine and Spruce stems. 
 The arrangement of the wood in a complete circle about 
 a central pith is the rule in the Gymnosperms. 
 
 THE FLOWERLESS PLANTS. 
 The Ferns. 
 
 1. Examine entire plants of as many of the following 
 Ferns as may be convenient: any variety of Adiantum, 
 
 Asplenium, Aspidium, 
 Polypodium, Osmunda, 
 Pteris, and Onoclea. 
 Do this in the field, if 
 possible ; otherwise in 
 the laboratory. 
 
 Only the leaves rise 
 above ground. Obser- 
 vation of the leaves as 
 they uncoil in the spring 
 
 FIG. 13. Transverse section of stipe of 
 
 should be made. The 
 
 Cinnamon Fern, Osmunda dnnamomea. lar g e underground por- 
 
 (x 35.) The curved figure is the fibro- tions are the stems, here 
 vascular bundle. ,, , ,. , 
 
 called rhizomes. Branch- 
 ing from these are small fibrous roots. In removing the 
 specimens from the ground, be careful to injure the 
 rhizomes and roots as little as possible. Compare the rhi- 
 
THE FLOWERLESS PLANTS. 
 
 35 
 
 zomes of the different specimens. Cut transversely across 
 each rhizome and examine the cut end with a magnifier. 
 Make a sketch of each. The arrangement of the bundles 
 of woody fibers, fibrovascular bundles, and the bundles of 
 dark colored hardened 
 woody tissue, scleren- 
 chyma, form character- 
 istic figures in the 
 cross sections. 
 
 2. Examine the leaf 
 or frond of an Aspidium 
 Fern. It is supported 
 by the stipe. It is com- 
 pound, the pinnae, branch- 
 ing off from the rhachis 
 or backbone of the 
 frond, these in turn be- 
 ing divided into pin- FIG. 14. Vertical section of stipe of Cin- 
 nules ' in some Species namon Fern, Osmunda cinnamomea, 
 
 showing the fibrovascular bundle, F, in 
 there are Still lUrtlier longitudinal section, (x 35.) 
 
 divisions. 
 
 Make a sketch of the entire frond, showing the vena- 
 tion on some of the pinnules. Is the leaf netted- veined or 
 parallel-veined ? Draw the back of one pinna, showing 
 the arrangement of the fruit dots or sori. Cut across 
 the stipe and examine the cut end with a magnifier. 
 Repeat these observations with a frond of Adiantum. 
 In Aspidium and Adiantum do all of the fronds bear 
 sori ? How is it with the other available species of 
 Ferns? Find fruiting forms of as many other Ferns 
 as possible, and make a comparison of the manners in 
 which the sori are borne. Are they covered with a dis- 
 tinct indusium, as in the Aspidium, or is the indusium 
 formed by the folding back of the edge of the leaf, as in 
 Adiantum ? Is the indusium lacking in any specimens ? 
 
36 .PRELIMINARY STUDIES. 
 
 Scrape off one of the sori upon a microscope slide and 
 examine under the low power of the compound micro- 
 scope. Notice the spores, which are borne in spore cases 
 or sporangia. 
 
 3. We here meet with spores for the first time in 
 descending the scale of plant life. The Ferns and the 
 plants below them produce no seeds. Seeds, in the 
 higher plants, result from the fertilization of ovules by 
 pollen grains. Seeds grow directly into ordinary plants 
 when the conditions are favorable. Spores result from 
 cell division. They contain no embryo and do not grow 
 into ordinary plants. The alternation of generations is 
 very distinct in the Ferns. The ordinary Fern plants are 
 the sporophytes or plants producing spores. 
 
 4. Spores grow by cell division. Sow Fern spores of 
 the previous year's production on sand and cover with 
 a bell jar. Keep moist and in a warm, light place, but 
 not in direct sunlight. Study the growth by cell division 
 by examining from time to time under the microscope, 
 both low and high powers, the green growth on the sand 
 that soon becomes just visible to the naked eye. These 
 growths are the protonemce. If the conditions are favor- 
 able, some of the protonemce will develop in six or eight 
 weeks into heart-shaped prothallia less than half an inch 
 in diameter. The prothallium is the gametophyte form 
 of the Fern, i.e., the form that bears male and female 
 cells which unite to produce again the sporophyte form or 
 the plant. The more minute study of the gametophyte 
 is best reserved for later work. It is well for the student 
 here to see the prothallium and to have his attention called 
 to the antheridia, or aggregations of cells which produce 
 the antherozoids, or minute male cells, the male gametes, 
 and to the aggregation of cells, the archegonia, that pro- 
 duce the oospheres, or female cells, the female gametes. 
 The male cells have the power of motion. At their ma- 
 
THE FLOWERLE88 PLANTS. 
 
 37 
 
 turity they swim, 
 when the prothal- 
 lium is wet with 
 rain or dew, to the 
 o o sp h e r e s, enter 
 and unite with 
 them. An do spore 
 is the result of this 
 union, and this 
 oospore grows into 
 an ordinary Fern 
 plant. If prothal- 
 lia are not pro- 
 duced by the cul- 
 ture on moist sand, 
 they may often be 
 found on the soil or 
 pots in which Ferns 
 are cultivated. A 
 neglected fernery 
 is quite sure to 
 yield specimens. 
 
 After a Fern 
 plant has once 
 started by this 
 mode of reproduc- 
 tion, it lives many 
 
 years. The Stem FIG. 15. Prothallium of a Fern, exhibiting the 
 I r 1-1 reproductive organs. At the sinus of the heart- 
 
 uaiiy wnoiiy shape d film are to be seen the archegonia, one 
 
 of which, more highly magnified, is displayed in 
 section in A. B, an enlarged antheridium, with 
 escaping antherozoids. (Luerssen.) 
 
 underground, only 
 the leaf rising 
 above ground. 
 
 5. Try to identify the common Ferns of your neigh- 
 borhood by analyzing with the help of Gray's " Manual " 
 or Underwood's " Our Native Ferns and their Allies." 
 
88 PRELIMINARY STUDIES. 
 
 The Mosses. 
 
 1. Polytrichum commune is decidedly the best Moss to 
 begin with on account of its large size and common occur- 
 rence. It is abundant everywhere by the roadside and in 
 waste places. The plants are from three to eight inches 
 high. The ordinary plant is the gametophyte, i.e., there 
 are male and female plants. The former bear motile 
 cells, which find their way to certain cells borne on the 
 female plants and unite with them. 
 
 In descending the scale of plant life we here first 
 reach plants that have no true roots. A true root has a 
 vascular structure, such as has been seen in the higher 
 plants. The Mosses and other lower plants have rhizoids, 
 which are mere filaments, each either a single cell or com- 
 posed of a series of cells. Examine the rhizoids under the 
 microscope. 
 
 2. Examine a male plant, which may be known by the 
 rose-shaped cluster of leaves at its "top. In the cells of 
 certain modified leaves of this cluster, minute antherozoids 
 are borne. These antherozoids resemble the antherozoids 
 of Ferns, and like them have the power of motion. The 
 antherozoid is the male gamete. 
 
 3. The female plant bears at its very top, concealed 
 among the leaves, an archegonium, i.e.* a cluster of cells 
 containing a cell, the oo sphere, which is capable of receiv- 
 ing antherozoids. The oosphere is the female gamete. 
 The union of the antherozoid with the oosphere pro- 
 duces an oo spore. The oospore is raised up above the 
 top of the female plant by a very slender stalk, the 
 seta, and develops there into the sporophyte form of 
 the plant. This remains fixed here until it has matured 
 its spores. 
 
 4. The enlarged top that develops on the female plant 
 is a sporangium. Examine and draw some of the spores 
 
FIG. Iti. Polytrirhum commune. S, sterile plant; M and P, male plants; 
 F, female plant; H, seta; C, sporangium. 
 
 39 
 
40 
 
 PRELIMINARY STUDIES. 
 
 FIG. 17. 1, Upper part of a female Moss 
 plant, showing club-shaped archegonia 
 concealed among the leaves; 2, an an- 
 theridium, such as are borne in the rose- 
 shaped cluster of leaves at the top of the 
 male plants, allowing the antheroids to 
 escape. Each of the cells at a contains 
 an antherozoid in a gelatinous covering. 
 (Thome'.) 
 
 under high power. The 
 ripened spores are scat- 
 tered over the ground, 
 and there develop into 
 simple aggregations of 
 cells, called protonemce. 
 These resemble the pro- 
 tonemse of Ferns, but 
 differ from them essen- 
 tially in their further 
 growth, which is by 
 sending off buds or side 
 branches. These buds 
 develop into the ordi- 
 nary Moss plant. 
 
 5. Certain plants of 
 Polytrichum are ster- 
 ile. In early spring 
 these may be mistaken 
 for the female plants, 
 but later the male, fe- 
 male, and sterile plants 
 are easily distinguished. 
 (See Fig. 16.) 
 
 The Pond Scums. 
 
 Collect from stagnant pools some of the slimy green 
 growth commonly known as Frog Spittle. Examine under 
 both low and high powers of the compound microscope. 
 Different varieties may be found. It will be sufficient for 
 the present purposes if any variety in the conjugating con- 
 dition is obtained, as these plants are to be studied more 
 minutely later. Material in the conjugating condition 
 that has been preserved in formalin or alcohol may be 
 
THE FLOWERLESS PLANTS. 
 
 41 
 
 used. Figure 18 shows one species of the pond scums in 
 suitable condition for this study. The plant is a thallus. 
 A thallus is the name applied to any plant that does not 
 have roots, stem, or leaves. All such plants are Thallo- 
 phytes. 
 
 The plants are one celled. They multiply by cell divi- 
 sion. The divisions take place at right angles to the 
 length of the cells, and, as the cells are covered with a 
 gelatinous coat- 
 ing, they hold to- 
 gether and form 
 long threads. 
 There must, how- 
 ever, be some or- 
 ganic difference 
 in the make-up 
 of the cells of 
 different threads, 
 for, at the proper 
 season of the year, 
 the cells of one 
 thread send out 
 little tubes to the 
 cells of some other 
 thread lying near, 
 and empty their 
 cell contents into 
 the cells of the 
 second thread. 
 The contents of 
 
 the two cells mill- 
 
 gle and form a 
 
 zygospore. This becomes encased in a comparatively thick 
 
 coating, i.e., it becomes encysted, sinks into the mud at 
 
 the bottom of the water, and preserves the life of the 
 
 FlG - 1. - Spirogyra. A t vegetative > cells; B, cells 
 conjugating. (X 480.) 
 
42 PRELIMINARY STUDIES. 
 
 plant until the following season. It then develops by 
 cell division into a new thread of the ordinary sort. 
 
 The Molds. 
 
 Keep pieces of moist bread under bell glasses until a 
 white growth develops on them. Allow this to mature ; 
 the maturity will be indicated by the formation of little 
 black knobs of microscopic size. Examine some of these 
 knobs under the microscope. Each knob is a sporangium 
 filled with spores. The spores are of the type known as 
 gonidia. When ripe sporangia are mounted in water for 
 examination under the microscope, they burst and scatter 
 their spores. By watching the cultivation and taking 
 young sporangia, better specimens may be obtained. 
 Draw a sporangium and some of the spores. 
 
 The plant is one of the Mucors. It is a saprophyte, i.e., 
 it lives upon decaying organic matter. It contains no 
 green coloring matter, chlorophyl, arid has no power to 
 assimilate mineral matters from the substratum on which 
 it grows or carbon from the air around. Its mode of life 
 is in a measure like that of the lower animals. 
 
 All ordinary plants which contain the green coloring 
 matter, chlorophyl, are holophytes, i.e., their mode of life 
 is wholly characteristic of plants. Unlike the saprophytes 
 and animals they have the power to assimilate mineral 
 matters from the soil or water in which they grow and 
 carbon from the carbon dioxide of the air. This power 
 resides in the green coloring matter, chlorophyl. 
 
 frotococcus. 
 
 1. Obtain some of the green incrustation which is so 
 conspicuous in wet weather on old trees, fences, and walls. 
 It is Protococcus. Examine under high power. It is a 
 
THE FLOWERLESS PLANTS. 
 
 43 
 
 one celled plant, multiplying by cell division. Study and 
 draw the little groups of cells that, for a time, cling 
 together. (See Fig. 19.) 
 The coherence between 
 the different plants of 
 these groups is very 
 slight, so that the groups 
 never become very large. 
 2. Put some of the 
 bark, bearing Protococ- 
 cus growth, in a glass of 
 water and set in a warm, 
 sunny place. Examine 
 drops of water, obtained 
 with the help of a cam- FlG . 19 ._p rotococcus , showingt hemulti- 
 
 plication of the plant by cell division. 
 a, single plant ; 6, plant dividing into 
 two ; c, group of plants that have re- 
 sulted from repeated divisions of a 
 single cell. (X480.) 
 
 el's hair brush from the 
 surface of the bark, daily, 
 for minute colorless oval 
 organisms like Fig. 20, 6, 
 which dart about rapidly. 
 
 They are zoo spores, i.e., ani- 
 / mal-like spores. At first 
 glance one would not 
 suppose there was any 
 connection between the 
 moving animal-like or- 
 ganisms and the cells of 
 Protococcus. Neverthe- 
 less these moving organ- 
 isms are not animals, 
 but are one stage in 
 
 a, plant preparing the development of the 
 
 plant. They have re- 
 sulted from the division 
 of the cell contents into a number of parts. Their motion, 
 which will be studied later, is produced by alternate con- 
 
 
 FIG. 20. Protococcus. 
 
 for division into four large motile cells ; 
 6, one of the large motile cells, showing 
 the cilia. 
 
44 
 
 PRELIMINARY STUDIES. 
 
 FIG. 21. Protococcus. A cell preparing 
 to divide into numerous small motile 
 cells. 
 
 of the Ferns, Mosses, and other higher plants. 
 
 tractions and expansions 
 of the two cilia which 
 each bears at one end. 
 It will be very . diffi- 
 cult for the beginner to 
 see these cilia. Special 
 means for detecting 
 them are given on page 
 86. A study of these 
 moving forms helps to a 
 better understanding of 
 the motile antherozoids 
 
 Plants and Animals. 
 
 Plants are, in general, characterized by the possession 
 of a cellulose cell wall. Through this wall solutions of 
 nutrient materials pass by osmosis. " These nutrient ma- 
 terials are simple in their nature, consisting mainly of 
 mineral salts tnat form naturally in the soil. In addition 
 to these dissolved nutrients, Morophyl-l earing or holo- 
 phytic plants obtain carbon from the carbon dioxide of 
 the air. The radiant energy from the sun effects the 
 changes which convert these inorganic substances into 
 living protoplasm, which is the life and essential part of 
 every living cell. ChloropJiyl-less or saprophytic plants 
 obtain their carbon from dissolved sugar and their nitro- 
 gen from other organic compounds, which have resulted 
 from previous forms of life. The first steps of the build- 
 ing-up processes have already taken place, and the sapro- 
 phytic plants are not dependent on the sunlight. Plants, 
 in general, are not capable of motion in the ordinary 
 sense, but some of the lowest forms and the reproductive 
 bodies of some of the more highly organized plants are, 
 
THE FLOWERLESS PLANTS. 
 
 45 
 
 as we have seen, capable of moving independently. 
 Plants excrete water, carbon dioxide, and oxygen, but 
 have no special organ of excretion. 
 
 Animals are characterized by the entire lack of cellu- 
 lose in their cell walls. Their nutrition is by the diges- 
 tion of somewhat complicated organic substances that are 
 taken into the animal through a mouth, which may be 
 only temporary, but is usually permanent. The waste 
 matters are removed from the organism through definite 
 organs of excretion, which also may be temporary, but are 
 usually permanent. Independent locomotion also charac- 
 terizes animals, though some live permanently attached to 
 fixed supports. 
 
 The Protista. 
 
 There are certain organisms in which these character- 
 istics that distinguish plants from animals are so com- 
 bined that the highest authorities do not undertake to 
 say whether the organism is a plant or an animal. To 
 these organisms the name Protista has been given. 
 To obtain an example of these organisms, allow water 
 weeds to go to decay in a vessel of water. Examine 
 some of the water from time to time under high power 
 until organisms resembling Fig. 22, e, are obtained. This 
 
 
 FIG. 22. Euglena viridis. e, the normal form ; a, b, c, d, forms going through 
 the Euglenoid movements. The clear circular space seen in each figure is 
 a contractile vacuole; the dark spot between the contractile vacuole and 
 the anterior end is the eye spot. (X 480.) 
 
46 PRELIMINARY STUDIES. 
 
 organism is Euglend viridis. The body is several times 
 as long as wide, and tapers towards both ends. By pecul- 
 iar contractions the organism executes movements which 
 are so peculiarly characteristic that they are known as 
 Euglenoid movements. Besides these motions, Euglense 
 make active, darting movements from place to place. 
 
 1. Hunt for forms that are executing the Euglenoid 
 movements. Study the changes of form, and draw Eug- 
 lenye in three or four typical positions. 
 
 2. Study Euglense in active motion. How is the 
 motion produced ? Look for a flagellum, a very fine 
 thread, at one end, and recall what was said about the 
 motile forms of Protococcus. The beginner will find 
 difficulty in seeing the flagellum. If it cannot be seen 
 in the living organism, run iodine solution under the 
 cover glass, and watch the Euglente as they die. Is the 
 flagellum on the anterior or posterior end ? 
 
 3. Examine a fresh mount of living Euglense for 
 chlorophyl. In what portion of the organism do you 
 find it ? Is it found in one or several Morophyl bodies ? 
 
 4. Near the anterior end notice a small, red spot. This 
 is known as the eye spot, but there is no reason for sup- 
 posing it to be an organ of sight. 
 
 5. Try to find encysted forms, i.e., forms that have 
 surrounded themselves with a thickened wall. The cell 
 wall is cellulose. 
 
 6. Observations that are too difficult for the beginner 
 show that the flagellum grows from the bottom of a hol- 
 low which communicates by a minute passage with the 
 interior of the organism. The lashing of the flagellum 
 causes currents of water to carry particles of solid matter 
 into the organism, where, it is believed, they are digested. 
 
 7. The possession of a cellulose wall in the encysted 
 condition, and the occurrence of chlorophyl would place 
 Euglena among plants ; the Euglenoid movements and 
 
THE FLOWEHLESS PLANTS. 
 
 47 
 
 the taking in of solid food through a permanent mouth 
 would place it among animals. There are still other 
 characteristics which are too difficult for observation by 
 the beginner, some of which would place Euglena among 
 plants, while others would place it among animals. 
 
 Animal Forms. 
 
 A consideration of a few of the lowest forms of animal 
 life will help the beginner to a better understanding of 
 the lowest forms of plants, and 
 particularly to a better under- 
 standing of the motile forms of 
 plants. The pupil will also be 
 better prepared to understand 
 the theory of evolutionists that 
 all life on the earth has devel- 
 oped from the same original 
 simple forms, plants being the 
 result of variations in develop- 
 ment along one line, animals of 
 variation along another line. 
 This consideration must be very 
 brief and superficial. 
 
 Paramcecium. The same 
 vessel of decaying water plants 
 that furnished the Euglense has 
 probably also produced Para- 
 moecia or Slipper Animalcules. 
 Study these under high power, 
 comparing with Fig. 23. Notice 
 particularly the fringe of minute hairs, or cilia, whose 
 lashings produce the movements of the organism. 
 
 Amoeba. Amoebae have also probably been produced 
 in abundance in the vessel that has provided the Euglense 
 
 FIG. 23. Paramoecium. The 
 figure represents the organ- 
 ism only in outline. The 
 circle in the lower part rep- 
 resents a contractile vacuole 
 in a state of rest. The cir- 
 cle in the upper part, sur- 
 rounded by dots, represents 
 a contractile vacuole in the 
 act of contracting to expel 
 waste products. The series 
 of dots shows the general 
 movement of food particles 
 within the organism. The 
 whole cell has a granular ap- 
 pearance, and these details 
 can be seen only by careful 
 observation. (X480.) 
 
48 PRELIMINARY STUDIES. 
 
 and Paramcecia. With a pipette transfer to a microscope 
 slide repeated portions of the sediment from the vessel 
 until good specimens of Amoeba are found, using the high 
 power, or with a camel's hair brush remove the Amoebae 
 from the surface of some of the larger pieces of de'bris 
 taken from the vessel. A little care must be exercised at 
 first in searching for them, or they will be overlooked. 
 They are so colorless and transparent, like little masses 
 of clear jelly, that only careful watching will enable the 
 beginner to make them out at first. After they have once 
 been recognized, there will be no trouble. 
 
 FIG. 24. Amoebae. The clear spot in each is a contractile vacuole. Each 
 contains particles of food in process of digestion ; a is in the act of surround- 
 ing a food mass. 
 
 1. Observe a difference between the central portion of 
 the organism and the portion around the edges. The 
 latter is very clear and transparent ; it is known as the 
 ectosarc. The central portion has a granular appearance ; 
 it is called the endosarc. 
 
 2. Watch the motions of different specimens. Observe 
 that projections of the ectosarc, pseudopods, are thrown 
 out ; after a time portions of the endosarc flow into these, 
 and a movement of the whole organism is caused. 
 
 3. Search for food particles in the endosarc. These 
 are easily distinguished from the protoplasm of the endo- 
 sarc. Watch Arncebse that are in active motion until 
 
THE FLOWER LESS PLANTS. 49 
 
 they are seen to surround food particles. Particles of 
 powdered carmine may be introduced to serve as food. 
 Observe also, if possible,, the rejection of refuse particles 
 from the body. These observations may require patient 
 and continued watching, but will well repay a little effort. 
 
 4. Find Amoebie which show contractile vacuoles. 
 These are clear spots which may be seen suddenly to 
 contract and then slowly to expand. It is believed that 
 the contractile vacuole is an organ for the excretion of the 
 liquid waste products. Euglense and Paramoecia also 
 have contractile vacuoles. 
 
 5. The lack of cellulose in the cell wall, the taking of 
 somewhat highly organized foods, the manner in which 
 these foods are taken and the method by which the refuse 
 is expelled from the body, the possession of contractile 
 vacuoles, and the character of the movements place 
 Amoeba among .the animals. It is the lowest form of 
 animal life, and in observing it the pupil will obtain a 
 very good idea of the appearance of simple protoplasm, 
 which is believed to be essentially the same wherever 
 it occurs, whether in plants or in animals. 
 
 CLARK'S BOX. 4 
 
I. 
 
 THE SLIME FUNGI. 
 
 The Slime Fungi (Myxomycetes) are mere masses of 
 protoplasm without definite shape. In appearance they 
 resemble some of the Protozoa so much that it is very dif- 
 ficult to distinguish them from the lowest forms of animal 
 life. Their manner of living does not help to decide the 
 question, for their nutrition is neither entirely holophytic 
 nor holozoic, that is to say, neither entirely after the 
 manner of plants, nor entirely after the manner of animals. 
 They live in part by the absorption of solutions of decaying 
 organic matter, i.e., after the manner of saprophytic plants ; 
 in part, by the digestion of particles of solid matter that 
 they have inclosed after the manner of the Amoeba, the 
 lowest of animals. So much do these organisms partake 
 of the nature of both plants and animals, that they are 
 classed as plants by some eminent scientists and, under the 
 name of Mycetozoa, as animals by others equally as well 
 qualified to judge, while still others evade the question by 
 making a third kingdom, that of the Protista, in which 
 these and other doubtful forms are placed. Because of 
 these doubts, and because of the simplicity of their struc- 
 ture, the Slime Fungi are placed by themselves at the low- 
 est point in the scale of classification. 
 
 The Slime Fungi vary in size from forms that must be 
 studied with the microscope up to forms several inches in 
 diameter, as in the large sulphur-colored forms known 
 as Flowers of Tan, the ^Ethalium septicum. They creep 
 about over the substratum on which they grow in a way 
 which resembles alike the movements of Amoebae arid, as 
 
 50 
 
THE SLIME FUNGI. 51 
 
 Hofmeister has pointed out, the movements of protoplasm 
 in the cells of the higher plants. These plants grow 
 better in the dark than in the light, and Sachs has shown 
 that they exhibit a marked irritability to the influence 
 of light. The Flowers of Tan are favorable plants for 
 study. These develop on piles of tan bark and on decay- 
 ing leaves and bark during hot, sultry weather. They 
 appear suddenly when the conditions of heat and moisture 
 are favorable, and run through their course of existence 
 within the space of a few days. If the conditions are 
 changed, they disappear. If masses of the tan on which 
 they have begun to develop are placed in the dark, the 
 slime spots collect on the surface ; if strong light is allowed 
 to fall on them, the spots creep down into the masses of 
 tan. It is, however, only during the earlier, plasmode 
 stage of their development that they exhibit this irritability 
 to light. During the later stages of development, they 
 flourish in strong light. Sachs has also shown that the 
 Slime Fungi are influenced by an apogeotropic stimulation 
 which causes them to ascend the stems of plants, or even 
 glass plates placed vertically in the substratum on which 
 they grow. Growths are thus easily obtained for micro- 
 scopic study. 
 
 Recent theories attribute certain malarial diseases to 
 species of the Slime Fungi which find entrance to the 
 human blood through the medium of drinking water and 
 there multiply in the amoeboid condition. In the blood 
 they are combated and eaten by the colorless amoeboid 
 corpuscles the phagocytes. Victory by the phagocytes 
 means recovery of health ; victory by the Slime Fungi 
 means death. 
 
 In their earlier stages these Slime Fungi form continu- 
 ous, or nearly continuous, masses of protoplasm, without 
 cell walls, without fixed shape, and without green color. 
 They are whitish, colorless, or of a yellow sulphur color, 
 
52 
 
 PRACTICAL BOTANY. 
 
 sometimes tinged with red. In the later stages of their 
 growth rounded masses appear in the protoplasm, each of 
 which develops a cell wall and becomes a resting spore. 
 Toadstool-like elevations also appear which bear resting 
 spores. The resting spores live after the moisture has 
 evaporated, and in the form of a dry powder are scattered 
 abroad by the wind until they strike some moist surface 
 where the conditions are favorable for their development, 
 when each spore is capable of growing into a new organism. 
 
 In the beginning of this 
 growth, the spore de- 
 velops into a motile 
 Amcebalike form. These 
 forms meet and flow to- 
 gether, forming the so- 
 il^ // ^fpl^i called plasmodia, which 
 fflgik^ 2&&#m i* 1 some cases attain a 
 
 considerable size. As 
 the. plasmodia increase 
 in size, a true flowing 
 movement takes the 
 place of the amoeboid 
 movements which char- 
 acterized the earliest 
 motile forms. In some 
 of the Slime Fungi, ciliated swarm spores form. These 
 move by a combined hopping, rotating, and creeping 
 motion, as well as by amoeboid movements. After a time 
 the cilia are lost, and the forms which now become 
 Amcebalike unite to form plasmodia. The earlier forms 
 of the Slime Fungi also multiply by repeated divisions 
 of the mass. There is no alternation of generations 
 from sporophyte to gametophyte ; the plant is the sporo- 
 phyte. There are, then, five distinct stages in the ex- 
 istence of these organisms, as follows : a. The spore, 
 
 FIG. 25. Physarum album. (From Sachs, 
 after Cienkowski.) 1, spore ; 2, emis- 
 sion of its contents ; 3, the free contents ; 
 4, 5, the same as swarm spore with one 
 flagellum ; 6, 7, the same after losing 
 their flagella; 8, 9, 10, 11, fusion of 
 amoeboid forms ; 12, a small plasmod- 
 ium. 
 
THE SLIME FUNGI. 53 
 
 Fig. 25. l. b. The contents of the spore become a naked 
 mass of protoplasm, provided with a flagellum by means 
 of which it moves, Fig. 25, 3, 4, 5. During this stage 
 multiplication may take place by division, c. The organ- 
 ism loses its flagellum and becomes amoeboid in character, 
 Fig. 25, 6, 7. d. Two, or more frequently several, amoe- 
 boid forms unite and form a plasmodium, Fig. 25, 8, 
 9, 10, 11. This moves and obtains its food, at least in 
 part, as does the Amoeba, e. The plasmodium secretes 
 a cell wall and so becomes encysted. The cell contents 
 then break up into spores. Figure 25, 12, shows a plas- 
 modium preparing for these changes. 
 
 The Slime Fungi are to be looked for in the water, on 
 the bark of trees, tan bark, decaying leaves or wood, and 
 in similar locations. Piles of tan bark afford especially 
 good ground to search for them. 
 
 References for Reading. Parker's " Elementary Biology," pp. 49-55 ; 
 Goebel's " Outlines of Classification," pp. 14-17 ; Carpenter's " The Mi- 
 croscope and its Revelations," pp. 563-565 ; Sachs' " On the Physiology 
 of Plants," pp. 82-84, 429, 430, 613 ; Bennett and Murray's " Crypto- 
 gamic Botany," pp. 401-404 ; Strasburger, Noll, Schenck, and Schim- 
 per's " Lehrbuch der Botanik," pp. 264-266. 
 
 "ERSITY 
 
II. 
 
 THE DIATOMS. 
 
 The Diatoms (J)iatomaceoR) are of very common occur- 
 rence. Not less than ten thousand species have been 
 
 described. 
 
 They occur in water, both still 
 and running, salt and fresh, 
 growing on the leaves and stems 
 of aquatic plants, or attached to 
 sticks and stones, or mingling 
 with the mud at the bottom. 
 They are brown in color, because 
 of the coloring matter called dia- 
 tomin, and are sometimes classed 
 with the Brown Algae for this 
 reason. They also contain chlo- 
 rophyl. Their exact position in 
 the classification of plants is not 
 easily determined, as they do not 
 seem to be connected even re- 
 motely with any other plants. 
 They are therefore given a place 
 by themselves in the classification. 
 The Diatoms occur as isolated cells, or connected in fila- 
 ments. The filaments sometimes partly separate, leaving 
 the cells strung together by their corners, forming striking 
 and characteristic patterns. Some forms grow on gelatine- 
 like stems. Diatoms vary in size from forms that require 
 a high power of the microscope to distinguish them to 
 forms that are plainly visible under the one-inch objective. 
 
 54 
 
 FIG. 26. Pinmtlaria viridis 
 Sm. A, valve view; B, 
 girdle view (diagrammat- 
 ic), m, raphe; g, central 
 node ; k, terminal nodules ; 
 a, outer and older valve ; 
 i, inner valve. (X 800.) 
 (From Bennett and Mur- 
 ray, after Pfitzer.) 
 
THE DIATOMS. 
 
 55 
 
 None are large enough to be seen with the unaided eye. 
 Some Diatoms resemble in shape certain Desmids, but the 
 brownish color of the Diatoms distinguishes them at once 
 from the bright green Desmids. Many species of the 
 Diatoms are capable of independent movement from place 
 to place. The manner in which the movements are accom- 
 plished is not well understood. 
 One theory is that the motions 
 are caused by currents of water, 
 which pass through small open- 
 ings in the organism, or perhaps 
 by osmosis through the thin par- 
 titions of the cells. Another 
 theory ascribes them to the con- 
 tractions of the protoplasm, which 
 protrudes through minute open- 
 ings in the cell wall. 
 
 The Diatoms are one celled 
 plants. A plant cell may be 
 considered as a closed or nearly 
 closed box, whose walls are com- 
 posed essentially of a substance 
 called cellulose. All living cells 
 are filled or lined with proto- 
 plasm, in which resides the true 
 life of the plant. The proto- 
 plasm of a plant cell has been 
 compared to a living snail, and 
 the cell wall to the snail's shell, 
 secreted by the snail, so the cell wall is secreted by the 
 living protoplasm within. In the filamentous forms of 
 Diatoms the cells are x simply associated together, but are 
 without organic connection. The association of unicellu- 
 lar organisms in filaments will be seen in some forms of 
 Bacteria, in the Zygnemese, and the Desmids, 
 
 FIG. 27. Gomphonema con- 
 strictum Ehrbg. s, view of 
 valves; g t , view of the girdle 
 corresponding to the right; 
 g,,, to the left margin of the 
 valves ; q, transverse section 
 through the middle of the 
 cell, showing with unusual 
 distinctness the composition 
 of the silicified cell wall of 
 two halves, one overlapping 
 the other (sa, the larger, si, 
 the smaller valve) ; k, the 
 nucleus ; p, dense proto- 
 plasm ; g t) (/,,, the two girdle 
 surfaces. (From Bennett 
 and Murray, after Pfitzer.) 
 
 As the shell has been 
 
56 
 
 PRACTICAL BOTANY. 
 
 FIG. 28. 1, cells of Synedra ulna attached to a plant cell; 2, a single cell 
 of Synedra ulna more highly magnified ; 3, Navicula liber, side view ; 
 4, Navicula liber, front view; 5, Navicula tumida, front view; 6, Navic- 
 ula tumida, side view; 7, Triceratium favus ; 8, Campy lodiscus spiralis; 
 9, Pleurosigma angulatum ," 10 and 11, Grammatophora serpentina ; 12 
 and 13, Gomphonema capitatum ; 14, Gomphonema capitatum on stalks 
 attached to plant cells ; 15, Diatoma vulgare ; 16 and 17, Fragilaria vires- 
 cens ; 18, Cocconema cistula ; 19, two cells of .Cocconema cistula prepar- 
 ing to form auxospores ; 20, the same after the auxospores have elongated 
 and are preparing to throw off the old cases which are seen on the right 
 and left. 19 and 20 show the cells enclosed in gelatinous sheaths. All of 
 these figures are highly magnified. (Kerner and Oliver.) 
 
 The individual cells are commonly spoken of as frustules. 
 The structure of these frustules is highly characteristic. 
 The foundation of the frustules is cellulose, heavily laden 
 with silica which has been deposited from the water in 
 countless numbers of exquisitely delicate and interesting 
 patterns. Each frustule is made up of two valves, one of 
 which overlaps the other like the cover of a box. (Fig. 26, 
 B and Fig. 27, q.) The junction of th8 two valves is 
 called the girdle. The frustules inclose a mass of proto- 
 plasm containing granules bearing chlorophyl and others 
 bearing the brown pigment that gives the prevailing color 
 to the organisms. 
 
 If gatherings of Diatoms be treated with boiling nitric 
 
THE DIATOMS. 
 
 57 
 
 acid, or sulphuric acid and potassium bichromate, the or- 
 ganic portions will be entirely removed, and the silicious 
 shells will be left uninjured. These shells, as well as the 
 living Diatoms, have been objects of great interest to 
 microscopists at all times on account of the great variety 
 of beautiful markings. The more delicate forms are also 
 highly esteemed as test objects for microscope objectives. 
 Besides the living forms there are numerous deposits of 
 the silicious shells of Diatoms in various parts of the 
 world. The accumulation of sediment formed by their 
 successive production and death in the waters of oceans, 
 lakes, and rivers gives rise to deposits that may attain 
 considerable thickness, and these, by subsequent changes of 
 level, may come to form parts of the dry land. 
 
 FIG. 29. 1, Surirella constricta, side view; 2, Pinnularia viridis ; 3, part of 
 a filament of Fragilaria pectinalis ; 4 and 5, side and front views of Terp- 
 sinoe musica, the so-called musical Diatom ; 6, Navicula. 
 
 Certain deposits in Norway and Sweden are known as 
 Bergmehl (mountain meal). They are used by the peas- 
 ants to mix with the flour in making bread. Fossil Dia- 
 toms are sold under various names as polishing powders, for 
 which purpose they are excellent, and are extensively used. 
 
 Diatoms may be obtained for examination from these 
 deposits, or the living forms may be secured by stripping 
 the yellowish-brown coating from the stems of water 
 plants, or by gathering the thin film of black mud from 
 the bottom of springs, ponds, and streams. 
 
58 PRACTICAL BOTANY. 
 
 Diatoms are reproduced both sexually and asexually. 
 By the asexual process the cell divides lengthwise by the 
 separation of its two valves. Each of the valves develops 
 a new valve to mate itself, and after a time the two new 
 cells separate entirely. The new valve always develops 
 on the inside of its mate, and is therefore smaller. If this 
 diminution were to continue indefinitely, the Diatoms 
 would, of course, practically disappear in time. 
 
 The sexual process of reproduction is evidently designed 
 to prevent this disaster. In this process the contents of 
 individual cells are set free from between the valves and 
 become zoospores. These zoospores unite in pairs, and 
 the resulting zygospore or auxospore develops into a large 
 form. (Fig. 28, 19, 20.) This new form is, however, 
 usually different from the parent form. By the sexual 
 process of reproduction nature not only prevents the ex- 
 tinction of the Diatoms, but provides for the production 
 of countless numbers of new species. A third process of 
 reproduction has been described by a few recent observers. 
 By this process the contents of cells are set free from be- 
 tween the valves, and each cell becomes an auxospore 
 without previous conjugation. 
 
 Although distinct sexual and asexual forms occur, the 
 life history of these plants is not fully understood. The 
 alternation of generations is by no means clear. The ordi- 
 nary asexual forms may be potential gametophytes, or they 
 may be sporophytes. 1 
 
 References for Reading. Bennett and Murray's " Cryptoganiic 
 Botany," pp. 419-426; Carpenter's "The Microscope and its Revela- 
 tions, "pp. 516-554; Goebel's "Classification of Plants," pp. 17-19; Stras- 
 burger and Hillhouse's "Practical Botany," pp. 210-213; Strasburger 
 Noll, Schenck, and Schimper's " Lehrbuch der Botanik," pp. 273, 274. 
 
 1 The pupil should be given gatherings both of recent and of fossil 
 Diatoms for examination. He should also be encouraged to collect mate- 
 rial for himself. The teacher can easily arrange a series of Practical 
 Studies on any forms that are conveniently obtained in the locality. 
 
III. 
 
 THE FISSION PLANTS. 
 
 The Fission Plants (JSchizophytes) naturally fall into 
 two classes: 
 
 CLASS I. THE BLUE-GREEN SLIMES (Cyanophycece). 
 CLASS II. THE BACTERIA {Schizomycetes). 
 
 CLASS I. The Blue-Green Slimes ( Cyanophycece) are 
 chlorophyl-bearing plants. They therefore belong to 
 the Algae, using this term in its broader sense. They 
 differ so much, however, in life history from the rest of 
 the Alg83 that they cannot be brought into classification 
 with them. On the other hand, they show certain resem- 
 blances in their structure and modes of development with 
 the Bacteria. They agree with the Bacteria in forming 
 resting spores, in multiplying by cell division, in not mul- 
 tiplying sexually, and in secreting heavy hyaline gelati- 
 nous envelopes. It therefore seems appropriate that the 
 Blue-Green Slimes and the Bacteria should be considered 
 by themselves. The Blue-Green Slimes also contain in 
 addition to chlorophyl the green coloring matter a 
 blue coloring matter pJiycocyanin. This is another 
 characteristic separating them from the rest of the Algae. 
 The two colors combined give the plants a bluish tinge. 
 
 No sexual reproduction is known to occur in this class. 
 There is consequently no alternation of generations from 
 sporophyte to gametophyte. The plant is the sporophyte. 
 
 Scattered through the protoplasm are granules that 
 are supposed to partake of the nature of nuclei, though 
 no true nuclei are found. The plants of this class occur 
 
 59 
 
60 PRACTICAL BOTANY. 
 
 in greater or less abundance in the gatherings from stag- 
 nant pools and ditches and in masses on moist rocks. 
 There are five orders in the Cyanophyceee. They are 
 the Chroococcacece, Nostocacece, Rivulariece, Oscillatoriece, 
 and Scytonemece. 
 
 In the Chroococcaceae the cells are enveloped in a trans- 
 parent gelatinous covering. The cells are found singly, 
 or associated in different small groups, which result from 
 the repeated division of single cells. Groups of three are 
 common. These plants occur as slimy growths in damp 
 places and in stagnant water, usually associated with other 
 kinds of plants. The two most common forms are Chro- 
 ococcus and Grloeocapsa. These are very simple organisms. 
 They are distinguished from other organisms by the uni- 
 
 FIG. 30. Gloeocapsa, magnified. 
 
 formity in the distribution of the minute blue-green 
 granules through the protoplasm and by their gelatinous 
 envelopes. In Gloeocapsa the envelope has two distinct 
 layers, which in the older forms are quite dark, facts that 
 serve to distinguish it from Chroococcus. The cells divide 
 by partitions running in all directions through the parent 
 cell and thus give rise to groups of cells. 
 
 The Nostocaceae form filaments which distinguish them 
 from other plants containing the blue-green coloring mat- 
 ter characteristic of this class. The filaments in some of 
 the species are more or less coiled in gelatinous envelopes. 
 The cells of the filaments are not uniform throughout, but 
 there occur at intervals larger cells that receive the name 
 heterocysts. There are three modes of reproduction. 
 
THE FISSION PLANTS. 
 
 61 
 
 First, by division of the cells in a direction transverse to 
 the length of the filament. Second, by the formation of 
 resting spores that develop into new filaments. Third, in 
 a special way by the formation of what 
 are called hormogonia. The parts of 
 the filaments between the heterocysts 
 escape from the gelatinous covering 
 after it has become more or less de- 
 cayed and dissolved. After a time 
 each of these fragments becomes in- 
 vested with a new gelatinous covering FIG. 31. A Nostoc. An- 
 and develops into a new filament by o^^WAft^rCook 1 ) 
 the division of its cells. 1 
 
 The Rivularieae are found as minute masses of dark 
 blue-green color in sluggish streams and in standing 
 water. The filaments radiate from the center of the 
 mass. The masses are seldom more than one or two 
 millimeters in diameter. 
 
 The Oscillatorieae occur as a dark blue-green scum on the 
 surface of stagnant water, about watering troughs, on wet 
 rocks, on Lily pads, and in similar locations. Examined 
 under the microscope, the filaments are seen to oscillate 
 slowly from side to side, a phenomenon that has not as 
 yet been satisfactorily explained. The plants multiply by 
 
 FIG. 32. Oscillaria, magnified. A single plant in the vegetative condition. 
 The filament has resulted from repeated transverse divisions of the cells. 
 
 the transverse division of the cells. Resting spores are 
 also formed, which continue the existence of the plant in 
 the dried state. 
 
 1 The teacher might arrange a series of Practical Studies, involving the 
 observation of these facts, on any species of Nostoc that is available. 
 
62 PRACTICAL BOTANY. 
 
 OSCILLATORIE^E. PRACTICAL STUDIES. 
 
 1. Collect a considerable quantity of the dark blue- 
 green plants from any of the above-mentioned locations, 
 dry and pulverize it, and place it in a clear glass dish 
 with some water for several hours. The water dissolves 
 the coloring matter known as phycocyanin and becomes 
 bluish. Remove the water, add strong alcohol, and boil. 
 The alcohol becomes yellowish green by dissolving out 
 the chlorophyl. 
 
 2. Mount a little of the fresh Blue-Green Slime in 
 water, i.e., place it on a microscope slide in a small drop 
 of water and cover with a cover glass. Under both low 
 and high powers of the microscope study the oscillations 
 of the filaments. Notice the tendency of the filaments 
 to radiate from a center. 
 
 3. Study the cells of a filament. Note the finely 
 granular protoplasm and its uniform distribution in the 
 cell. Compare a branch of Nostoc, .noting the sizes of 
 the cells and the positions of the heterocysts or enlarged 
 cells in the Nostoc. Find short filaments of Nostoc that 
 have broken off at the heterocysts to form hormogonia. 
 Such filaments are frequently found in stagnant water. 
 Draw part of a filament of Oscillaria and one of Nostoc, 
 showing the characteristic structures. 
 
 4. Observe the gelatinous sheath inclosing the fila- 
 ment. This is much more distinct in some species than 
 in others. In some species it is wholly wanting. In diffi- 
 cult cases it is best seen at the broken ends of filaments. 
 
 5. Notice the turgidity of the cells, i.e., their swollen 
 appearance, due to the fact that the internal pressure of 
 the water that has been absorbed by the protoplasm is 
 greater than the external pressure. This is best observed 
 at the broken ends of filaments where the cell wall is 
 bulged out by the internal pressure. 
 
THE FISSION PLANTS. 63 
 
 6. In each of two test tubes containing a small quantity 
 of ordinary water place a little of the Oscillaria and set 
 the two tubes in a sunny window, having first wrapped 
 one of them in thick, opaque paper to shut out the light. 
 All conditions are the same for the two tubes except the 
 light. After a day or two examine. What conclusion do 
 you draw as to the necessity of the light for the healthy 
 growth of the plant ? 
 
 7. Place a little Oscillaria in a test tube with ordinary 
 water and set in a window. By its side place some of the 
 Oscillaria in water that has been boiled to expel the car- 
 bon dioxide which is contained in all natural water. 
 From time to time compare the plants in the two tubes. 
 What conclusion do you draw as to the necessity of car- 
 bon dioxide for the healthy growth of the plant? 
 
 References for Reading. Goebel's "Classification of Plants," pp. 
 20-23 ; Vines' " Text-Book of Botany," pp. 231-233 ; Bennett and * 
 Murray's " Cryptogamic Botany," pp. 426-449. 
 
 CLASS II. The Bacteria (Schizomycete*). These plants 
 are also known as Fission Fungi. That the Bacteria belong 
 in this place in the classification admits of serious doubts. 
 To find that they are related to any other group of plants 
 is equally, if not more, difficult. Some authorities place 
 them by themselves as a group of. the Protista, organ- 
 isms that possess characteristics of both plants and ani- 
 mals. Others class them as undoubted Fungi, but they 
 differ too much in their life history from the rest of 
 the Fungi to be treated with them. Resemblances to the 
 Blue-Green Slimes in their modes of reproduction by the 
 transverse division of cells, and in the formation of resting 
 spores to continue their life in time of drought, make it 
 proper that they should be considered in this place. The 
 plant is the sporophyte ; there is no alternation of genera- 
 tions. 
 
64 PRACTICAL BOTANY. 
 
 The nutrition of the Bacteria is in general that of sap- 
 rophytic plants, i.e., of those that live on decomposing 
 organic matter. Some forms live as parasites. This is 
 the fact in the case of the forms which thrive in the liv- 
 ing tissues of animals, producing disease. At least three 
 species Bacillus virens, Bacterium chlorinum, and Bacte- 
 rium viride are known to contain chlorophyl, and their 
 nutrition must be in part or wholly holophytic, i.e., like that 
 of the green plants. Bacillus amylobacter also produces 
 a substance which, when treated with a solution of iodine, 
 gives a blue color which is characteristic of the reaction 
 of starch. Starch is the product of chlorophyl-beariiig 
 plants. Some species live and multiply in solutions that 
 contain no organic matter, a fact which tends to support 
 the theory of evolutionists that the earliest forms of life 
 were Protista, and that plants and animals have developed 
 from these by gradual evolution in different directions, 
 which have been determined by local conditions. 
 
 Many forms of Bacteria possess the power of moving 
 from place to place. These motions are in some cases 
 believed to be produced by the action of cilia ; in other 
 cases it is believed that they are caused by contractile 
 movements of the protoplasm. 
 
 The ordinary mode of multiplication of Bacteria is by 
 the transverse fission, of the cell. In some cases the 
 newly formed cells separate ; in other cases they remain 
 in contact, held together by a hyaline, gelatinous secre- 
 tion, forming filaments of some length. Another mode of 
 continuing the existence of the organisms, which obtains 
 in some species when the conditions of nutriment and 
 moisture are unfavorable for the fission of the cells, is 
 by the formation of resting spores. These spores form in 
 the center of most of the cells, one in each. They are 
 the resting condition of the organism and possess much 
 greater vitality than the cells. In the spore condition 
 
THE FISSION PLANTS. 65 
 
 the Bacteria may exist for indefinite periods of time, and 
 will endure much higher temperatures than the ordinary 
 forms. In this condition they are wafted about from 
 place to place in the air. When they meet with condi- 
 tions favorable to the life of the organism the spores 
 develop into cells, which multiply by the usual process 
 of fission. 
 
 Bacteria occur everywhere, accomplishing both good and ' 
 harm. The air, in its purest condition, contains numerous 
 spores. Putrefaction and fermentation of all kinds are 
 brought about by the direct agency of these organisms. 
 It is settled beyond dispute that many infectious diseases 
 are caused by Bacteria. Other Bacteria are not only 
 harmless but are believed to be essential to life in aiding 
 jiL-the digestion of the food. Some are profitably culti- 
 vated and sold to the makers of butter and cheese for 
 producing desired states and conditions. Other forms 
 are absolutely essential to the life of the higher plants 
 in bringing about nitrification in the soil, thereby furnish- 
 ing food materials for plants. 
 
 Bacteria exert a very important influence on the sub- 
 stances in which they grow. In the case of the pathogenic, 
 or disease-producing Bacteria, by-products, known as pto- 
 maines and toxins, are formed. These poisonous products 
 are the active influences in causing the disease. These 
 poisons have been isolated from the bodies of animals that 
 have died of different diseases. When tried on animals 
 known to be capable of taking these diseases, they are found 
 to work with great virulence. Notable instances of toxins are 
 the poisons produced by the Bacteria that cause the changes 
 in fish, meat, and ice cream. It is fortunate, however, for 
 man and animals that the products formed by far the 
 greater number of Bacteria are not poisonous, so that the 
 Bacteria which we are constantly taking into our systems 
 with our food and water only in exceptional cases work 
 
 CLARK'S HOT. 6 
 
66 PRACTICAL BOTANY. 
 
 injury. Some putrefactive Bacteria act as organized fer- 
 ments. The conversion of the sugar of milk into lactic 
 acid by Bacterium lactis in the souring of milk, and the 
 production of acetic acid from alcohol and oxygen by 
 Bacterium aceti in the souring of wine, are examples. 
 The nitrification of the soil already mentioned is still an- 
 other example of the action of a bacterial ferment. 
 
 Various classifications of Bacteria have been proposed, 
 but none are very satisfactory on account of the difficulties 
 in the way of their study, and because of the still unde- 
 veloped state of bacteriology as a science. It is not yet 
 settled that forms which are now generally considered as 
 genera may not be different stages in the life history of 
 the same species, so that the study of the morphology of 
 Bacteria gives very indefinite results. It is, however, 
 convenient to distinguish the different forms in a rough 
 way, and the following names have been adopted : Bacterium 
 denotes a short, thick, straight rod; Bacillus, a longer, 
 slimmer, straight rod ; Leptothrix, .unbranched filaments 
 in which the segments can usually be distinguished only 
 after treatment with stains ; Micrococcus, a small sphere ; 
 Vibrio, Spirochceta, Spirillum, coiled forms. De Bary 
 illustrates the three principal forms by " a billiard ball, a 
 lead pencil, and a corkscrew." 
 
 BACTERIA. PRACTICAL STUDIES. 
 
 1. Mount a little of the fur from your teeth in a drop 
 of water. Scrape the teeth just under the gums with a 
 knife point. Place a little of the scrapings in a drop of 
 water on a cover glass. Put another cover glass upon it, 
 press and rub the two cover glasses together until there 
 is a thin film on each. Mount by inverting one of the 
 cover glasses on a small drop of water on a microscope 
 slide. Examine with high power and find Micrococci, 
 
FIG. 33. Forms of Bacteria. 1, 2, 4, and 5, Micrococci; 3, zoogloea stage 
 of Micrococci ; 7, sarcina or packet forms of Micrococci resulting from 
 successive divisions in different directions; 8, 9, and 10, zoogloea stages 
 of Bacilli; 11 and 12, forms of Bacterium; 14, Leptothrix filaments; 
 15 and 10, Bacilli and Spirilla, showing spores; 17, Vibriones; 18, 19, 20, 
 and 21, Spirilla ; 22, Spirochaetse ; 23, zoogloea stage of Spirochsetse. 
 
 07 
 
68 PRACTICAL BOTANY. 
 
 Bacilli, and Spirilla. The comma-shaped forms resemble 
 the Comma bacillus of cholera. Run iodine solution under 
 the cover glass and observe that the longer rods are made 
 up of segments. They are Leptothrix forms. Draw. 
 
 2. Steep some vegetable matter of any kind in water. 
 Filter the solution into two flasks and boil for twenty 
 minutes. Stop both flasks with cotton- wool plugs. After 
 twenty-four hours repeat the boiling with the cotton-wool 
 plugs in the flasks. After another twenty-four hours 
 repeat the boiling. Now set the flasks away for several 
 days, allowing the cotton wool plug to remain undisturbed 
 in one; removing it from the other. 
 
 Examine the flasks daily. Account for the fact that 
 the liquid in the closed flask remains unchanged, while 
 that in the open flask becomes turbid. Notice that a skin 
 forms on the surface of the liquid in the open flask, -- the 
 pellicle or zoogloea, stage of Bacteria. This pellicle begins 
 to form as soon as the conditions become unfavorable for 
 further growth by cell division. It is during this stage 
 that resting spores are principally formed. 
 
 Examine under the microscope daily some of the liquid 
 from the open flask, using the high power. There will 
 usually be found at first a short rod form with rounded 
 ends and a constriction at the middle, Bacterium termo. 
 Later the longer rods and Leptothrix filaments of Bacillus 
 subtilis will be abundant. Other forms may be present. 
 
 3. Let five ounces of Pasteur's fluid with much sugar 
 receive a little yeast and work for a day or two. Kill the 
 yeast by heating above 50 C. Set aside for two or three 
 days and then examine the liquid below the zoogloaa. 
 Spread a little on a cover glass in a thin, even layer, dilut- 
 ing with water if necessary, and let it dry in the air. 
 Then, holding the cover glass, prepared side up, with the 
 forceps, pass it several times back and forth through the 
 hot air just above a gas flame to fix the Bacteria thoroughly 
 
THE FISSION PLANTS. 69 
 
 to the cover glass. Be careful not to burn. Float the 
 cover glass, prepared side down, on a solution of gentian 
 violet for ten minutes or longer. Wash by immersing in 
 water, let it dry in air, and pass through the hot air above 
 a flame. Invert the cover glass on a small drop of Canada 
 balsam on a slide. Preserve as a permanent mount. 
 
 4. Examine a bit of the pellicle formed on the Pasteur's 
 solution and also some of that on the solution of vegetable 
 matter. Observe that the Bacteria are motionless and 
 that they are imbedded in a transparent, gelatinelike 
 mass. 
 
 5. Allow a piece of raw fish or meat to stand in a vessel 
 of water for some days. Examine from time to time for 
 Bacteria. The succession of forms that will appear will 
 afford good material for instructive study. Among other 
 forms, numerous motile spiral forms will be found, 
 Spirilla and Spirochsetse. Draw some of the larger forms. 
 
 6. In a similar way study the Bacteria that will surely 
 be found in any other putrefying substances. 
 
 7. After Bacteria have been found in abundance in 
 the Pasteur's solution (see Number 3), place a little of 
 the solution in each of two test tubes. Wrap one of the 
 tubes in thick, opaque paper. Set the two tubes aside 
 for two or three days or more, with all other conditions 
 the same for both. Determine whether light is necessary 
 for the growth of the Bacteria. 
 
 References for Reading. Parker's "Elementary Biology," pp. 82- 
 94 ; Bidgood's " Elementary Biology," pp. 59-71 ; Klein's " Micro- 
 Organisms and Disease " ; Woodhead's " Bacteria and their Products " ; 
 Huxley and Martin's "Practical Biology," pp. 408-414; Vines' " Text- 
 Book of Botany," pp. 280-283 ; Goebel's " Classification of Plants," 
 pp. 24-27; Sachs' "Physiology of Plants," pp. 384-386; Schenck's 
 " Manual of Bacteriology " ; Strasburger and Hillhouse's " Practical 
 Botany," pp. 221-224; the author's "Practical Methods in Micros- 
 copy," 2d ed., pp. 171-197; Strasburger, Noll, Schenck, and Schim- 
 per's " Lehrbuch der Botanik," pp. 269-272. 
 
IV. 
 
 THE ALGJE. 
 
 The Algae are all chlorophyl-bearing plants. A very 
 large number of plants is here included. They are all 
 comparatively simple, but differ among themselves widely 
 in the degree of complexity of structure. They all live 
 in the water, though certain forms can exist in a dried-up, 
 inactive condition for indefinite periods of time ; these 
 latter forms multiply and develop only when moisture is 
 present. 
 
 In the processes of reproduction there is a considerable 
 range of variation. It is believed that both a sexual and 
 an asexual mode of reproduction occur in nearly all cases; 
 this point is not, however, settled in quite a number of 
 families, owing to the lack of sufficient investigation. 
 The mode of asexual multiplication differs in the different 
 families from the simple fission of the cells to the forma- 
 tion of nonmotile tetraspores in one class up to the for- 
 mation of self-motile zoospores, which is the prevailing 
 mode. 
 
 The possession of chlorophyl is not the principal reason 
 for associating together the plants known as Algee ; it is 
 the general similarity of the course of development of the 
 plants which has determined this point in the classification. 
 Neither is it merely the possession of the green, brown, 
 and red colors which determines the separation of the 
 Algae into their three principal classes: it is rather be- 
 cause, in each of these classes, the course of development 
 shows distinctive characteristics. 
 
 70 
 
THE ALG^E. 71 
 
 The principal classes are: 
 
 CLASS I. THE GREEN ALG^E (Chlorophycece). 
 CLASS II. THE BROWN ALG^E (Phceophycece). 
 CLASS III. THE RED ALG^E (Rhodophycece or Floridece). 
 
 CLASS I. The Green Algae (Chlorophycece). Simplicity 
 in the cell structure of the thallus is a characteristic of 
 the Green Algse. The position of the cilia at the ex- 
 treme tip of the zoospores is a further characteristic. The 
 plants are either single cells, filaments of cells, or super- 
 ficial cell surfaces, approaching the structure of solid cell 
 aggregates in the Stoneworts. The color is a pure green 
 except in some resting spores and in the reproductive 
 branches of the Stoneworts, which become red, brown, 
 or black by the formation of decomposition products in 
 the chlorophyl. 
 
 There is in many cases an alternation of generations 
 from sporophyte to gametophyte. The asexual multipli- 
 cation is in some cases by the simple fission of cells; in 
 others by the formation of ciliated zoospores ; in some 
 cases no asexual multiplication is known to occur. The 
 sexual multiplication is in some plants by the union of two 
 cells that are apparently just alike. When union takes 
 place between cells of the same form, it is said to be isoga- 
 mous. This union is called conjugation ; the cell that 
 results is called a zygospore. In other plants the sexual 
 multiplication is by the union of one cell with another of 
 quite different appearance. The male gamete is called an 
 antherozoid or spermatozoid ; the female gamete, an oo sphere. 
 The cell which results from this union is called an oospore, 
 and the union is said to be heterogamous or oogamous. 
 
 The subdivisions of the Green Algse are the Siphonece 
 or Cceloblastce, Volvocinew, Protococcacece, and Confervoi- 
 dece. The Conjugate and Characece are considered to be 
 forms collateral with the Confervoideae. 
 
72 
 
 PRACTICAL BOTANY. 
 
 The Siphoneae or Coeloblastae. These are branched 
 filamentous plants, each consisting of one cell, there being 
 no transverse divisions except where the reproductive 
 
 FIG. 34. Vaucheria. Filaments of the plant in the vegetative condition, 
 showing the mode of branching and the lack of partitions. 
 
 organs are formed. The protoplasm is continuous through- 
 out the filaments. The plants vary considerably in size, 
 and occur under somewhat different conditions. They 
 are of common occurrence in both fresh and salt water. 
 
THE ALG^E. 
 
 73 
 
 The Siphonere are well represented by the Vaucheriaceae 
 or Green Felts. These are for the most part fresh-water 
 plants, though a few species are found in salt water. 
 They grow in the water and on the bottom and sides of 
 ponds and ditches, and on the wet ground around springs, 
 forming feltlike masses of a dark 
 green color. They are abundant 
 in damp places in greenhouses 
 on the ground, and on the sur- 
 face of the soil in the beds and 
 in the flower pots. The lack of 
 partitions across the filaments at 
 once distinguishes these plants 
 from the other Green Algse. 
 The protoplasm does not fill the 
 filaments but, leaving the cen- 
 tral portion empty, forms a thin 
 lining next to the cellulose wall. 
 Minute chlorophyl granules, to- 
 gether with numerous little 
 shining drops of oil, are scat- 
 tered regularly through the pro- 
 toplasm. Numerous nuclei are 
 present, but they are difficult of 
 demonstration. 
 
 No alternation of generations is known to exist in the 
 Siphoneye. The plant is the gametophyte. 
 
 FIG. 35. Vaucheria. 6, fruit- 
 ing filament ; c, antherid- 
 ium; d, oogonium; e, resting 
 spore. Magnified. 
 
 VAUCHERIA. PRACTICAL STUDIES. 
 
 1. Examine with the naked eye and with a hand mag- 
 nifier a quantity of Vaucheria. Notice its dark green 
 color and feltlike appearance. 
 
 2. Mount a little in water and examine with the low 
 power. To secure good mounts care must be exercised, 
 
74 PRACTICAL BOTANY. 
 
 as the plant is very delicate. Place a mass of the 
 Vaucheria in water and agitate the water until some of 
 the plant filaments separate from the mass, free from 
 adhering dirt. Transfer some of these filaments to a 
 slide with a camel's hair brush. To prevent crushing the 
 plant support the cover glass with pieces of very thin 
 cover glass, or even with bits of paper. Notice that each 
 plant is made up of a single branched cell. Look for 
 colorless rhizoids, which may be found if the specimen 
 grew on the surface of soil. Draw a typical filament. 
 
 3. Observe the green chromatophores scattered uni- 
 formly throughout the cell. Treat with iodine solution. 
 Is starch present ? Iodine solution turns starch blue or 
 blue black. Treat a quantity of Vaucheria with alcohol 
 for some minutes. Note the color of the alcohol. What 
 is the effect on the color of the Vaucheria ? To a little 
 of the alcoholic solution of chlorophyl in a test tube add 
 an equal volume of benzol and shake. The benzol, which 
 separates and rises to the top, extracts a blue-green color, 
 leaving the alcohol colored yellow green. The starch is 
 formed in the chlorophyl bodies and is dependent upon 
 the healthy condition of the chlorophyl. 
 
 4. Place some Vaucheria in ordinary water and another 
 portion in water that has been boiled to drive out the 
 carbon dioxide. Set both in the sunlight for some hours. 
 Observe whether bubbles of gas rise in equal abundance 
 from both. The gas is oxygen. Chlorophyl-bearing plants 
 decompose carbon dioxide, assimilate the carbon, and set 
 oxygen free. Test some of the Vaucheria from each 
 vessel for starch. Is carbon dioxide necessary for the 
 production of starch ? Let both vessels stand two or 
 three days. Is carbon dioxide necessary for the healthy 
 growth of the plant ? 
 
 5. Place some Vaucheria in each of two vessels of ordi- 
 nary water. Expose one to direct sunlight and exclude 
 
THE ALG^E. 75 
 
 the light entirely from the other, having all other condi- 
 tions the same. After two or three days determine 
 whether the sunlight is necessary for the healthy develop- 
 ment of the plant. 
 
 6. In a fresh mount of Vaucheria look for bright shin- 
 ing oil globules scattered among the chromatophores. 
 Treat with a one per cent solution of osmic acid. This 
 demonstrates the presence of oil globules by turning them 
 black. 
 
 7. Run under the cover of a fresh mount ten per cent 
 salt solution and study the primordial utricle or layer of 
 protoplasm which lines the cell. The salt solution finds 
 easy entrance through the cellulose cell wall, but does not 
 so easily find entrance to the cell contents. It also extracts 
 water from 'the cell contents, which consequently assume 
 a diminished volume. This treatment is called plasmolyz- 
 ing the cell. 
 
 This experiment is also very instructive as illustrating 
 the manner in which the solutions that furnish nutriment 
 to plants which grow wholly immersed in water find en- 
 trance to the cells. As a further illustration, tie pieces of 
 bladder over the ends of a short piece of glass tube, of 
 a diameter of about half an inch, having filled the tube 
 with a saturated solution of sugar in water. Immerse in 
 water, and after a time the bladder diaphragms will be 
 bulged out because water has passed through them into 
 the sugar solution by endosmosis ; sugar also passes out by 
 exosmosis, as may be determined by tasting the water or 
 submitting it to chemical tests. 
 
 8. Run dilute caustic potash under the cover of another 
 preparation and study the cell wall. Treat still another 
 mount with Schultze's solution ; this solution stains nor- 
 mal cellulose blue or violet. Is the cell wall composed of 
 normal cellulose? 
 
 9. Keep some of the Vaucheria moist and in the dark 
 
76 PRACTICAL BOTANY. 
 
 for some time previous to the examination. Mount some 
 in water without a cover glass and look for filaments with 
 enlarged ends. If present, find as many different stages 
 of development as possible. This is the asexual mode of 
 reproduction. The ends of the filaments enlarge and be- 
 come cut off from the rest of the filament by a septum ; 
 the protoplasmic contents assume an ovoidal form and 
 become invested with cilia arranged in pairs; the end 
 of the filament opens, and the zoospore swims out by the 
 action of its cilia. The motion of the zoospore may con- 
 tinue for only a few minutes, or it may last for some 
 hours. As soon as it comes to rest it loses its cilia, 
 develops a cell wall, and grows into a new plant. The 
 observer who succeeds in finding these zoospores is re- 
 warded by the sight of one of the most beautiful objects 
 in the plant world. The zoospores are gonidia. 
 
 The observation of the formation of zoospores in a spe- 
 cies of Vaucheria by the botanist linger in 1826 was the 
 discovery of the fact that certain plants pass through a 
 motile stage in their existence. The discovery of proto- 
 plasm and the correction of the older idea that the cell 
 walls possess life was a natural sequence to this discovery. 
 No other discovery has had so much to do with the revo- 
 lution that botanical science has undergone in the last 
 half century. 
 
 10. Find filaments bearing the sexual reproductive or- 
 gans. In most species of Vaucheria both the male and 
 female organs are borne on the same filament, i.e., the 
 plants are monoecious. These organs originate as lateral 
 branches near together on the same side of the filament. 
 (See Fig. 35, c and d.) 
 
 As the oogonium matures, it assumes a shape that has 
 been described as "like a bird's head"; a septum forms 
 at its base which separates it from the filament, thus form- 
 ing the ovary ; its distal end becomes gelatinized and 
 
THE ALG7E. 77 
 
 breaks away, leaving the naked protoplasm within ex- 
 posed. This protoplasm is the female gamete ; it is some- 
 what ovoidal in shape, is coarsely granular, and is of a 
 dark green color. 
 
 The antheridium is longer and more slender and is 
 curved. It is lighter in color, as there is but little chlo- 
 rophyl present. The distal end becomes cut off from the 
 rest by a transverse partition ; the protoplasm of this por- 
 tion breaks up into numerous antherozoids, each having 
 a pair of flagella, the male gametes. 
 
 When fully mature, the antherozoids swim out through 
 the upturned outer end of the antheridium and find their 
 way to the entrance of the oogonium. One, at least, of 
 the antherozoids fertilizes the ovum. A resting spore is 
 thus formed, which assumes a reddish-brown color, be- 
 comes encysted in a thick cellulose wall, and develops 
 oil globules in the interior. After its period of rest, the 
 resting spore develops into an ordinary Vaucheria plant, 
 which passes through several generations by the asex- 
 ual mode of reproduction before resting spores are again 
 formed. Draw a typical pair of the reproductive organs. 
 
 References for Reading. Parker's "Practical Biology," pp. 169- 
 175 ; Dodge's " Elementary Practical Biology," pp. 267-272 ; Boyer's 
 " Elementary Biology," pp. 124-127; Bower's "Practical Botany," pp. 
 429-436 ; Goebel's " Classification of Plants," pp. 32-34 ; Strasburger 
 and Hillhouse's "Practical Botany," pp. 250-254 ; Sachs' " Physiology 
 of Plants," pp. 732-734 ; Bennett and Murray's " Cryptogamic Botany," 
 pp. 280-282; Carpenter's "The Microscope," pp. 491-493. 
 
 The Volvocineae. The characteristic that distinguishes 
 these plants is the formation of a coenobium, which is a 
 colony composed of cells that result from repeated fissions 
 of a mother cell. The number of cells that compose the 
 colony is always some multiple of two. These cells are 
 held together in regular form by a sheath of a gelatinous 
 nature. Here are included some forms of singular beauty 
 
78 
 
 PRACTICAL BOTANY. 
 
 and interest. Among the common organisms are the 
 following : 
 
 Pandorina is a sphere made up of sixteen minute cells 
 inclosed in a gelatinelike mass. Each cell is provided 
 with a pair of flagella, which project through the gelati- 
 nous envelope. 
 
 The reproduction of the plant is effected in two ways, 
 asexually and sexually. The asexual reproduction is by 
 the breaking up of each of the sixteen original cells into 
 , sixteen still more minute 
 
 cells. The gelatinous 
 covering then dissolves 
 and sets these sixteen 
 young groups of cells 
 free. Each group be- 
 comes invested with an 
 envelope of its own and 
 develops into a full-sized 
 sphere. 
 
 FIG. 36. - Pandorina morum Ehrb. a, Tne beginning of the 
 
 swarming coenobium inclosed in a gel- sexual prOCCSS is similar 
 
 atinous sheath ; b, c, swarm cells ; d, e, j. J.-L 1 TT Vi -F 
 
 conjugation of gametes;/, resting spore. *P kne asexual. Jiacn OI 
 
 (X 500.) (From Bennett and Murray, the Original sixteen cells 
 
 after Pringsheim.) , , . , . . 
 
 breaks up into sixteen 
 
 cells, each of which is set free by the breaking away of 
 the gelatinous covering. Each cell is provided with two 
 flagella which enable it to move about. Two of these 
 cells meeting (Fig. 36, d and e) unite their contents into 
 a spherical mass which becomes invested with a cell wall. 
 The sphere thus formed is the resting spore. (Fig. 36,/.) 
 After a time, when the conditions for growth are favor- 
 able, the cell wall decays and sets free the two or three 
 little cells that have formed within it. Each of these 
 cells has a pair of flagella. After a period of activity, 
 it comes to rest, and the cell contents divide and sub- 
 
THE ALG^E. 
 
 79 
 
 divide to form sixteen cells covered with a gelatinous 
 envelope, thus producing a new plant similar in all re- 
 spects to the original. 
 
 Volvox globator is another quite common organism. 
 It is a gametophyte. This tiny little organism, which 
 has long been an object of peculiar interest to micros- 
 copists, is the best known plant of its class. It reaches 
 a size just visible to the naked eye, and is found floating 
 on the water in still pools. A good way to look for it 
 is to place quantities of 
 pond weeds and scums 
 in glass dishes, allow 
 them to stand undis- 
 turbed for a time, and 
 then search with a hand 
 magnifier for little green 
 specks rolling through 
 the water. Volvox was 
 long supposed to be an 
 animal; later it was re- 
 garded as a colony of an- 
 imals. Professor Stein, 
 an eminent German bi- 
 ologist, describes it as 
 an animal, in a work 
 published in 1878. Biologists now generally class it as a 
 colony of plants, though some prefer not to express a posi- 
 tive opinion. The colony is spherical in shape, the inte- 
 rior being hollow. The shell of the sphere, so to speak, 
 is composed of a great many little green cells. These 
 cells are larger at one end than at the other, and the little 
 end, which has a pair of flagella, protrudes from the sur- 
 face of the sphere. The colony is motile, the motion 
 being produced by the lashing of the water by the flagella. 
 Under their combined influence the colony rolls or glides 
 
 FIG. 37. Volvox globator, showing the 
 formation of daughter colonies in the 
 interior. 
 
80 PRACTICAL BOTANY. 
 
 along, or simply rotates in its position without motion 
 from place to place. 
 
 The whole colony is green in color because of the 
 presence of chlorophyl granules in the protoplasm of the 
 flagellate cells. These cells closely resemble the flagellate 
 cells of Protococcus pluvialis, and could hardly be distin- 
 guished from them were it not for the manner in which 
 they form spherical aggregations, while the cells of Pro- 
 tococcus naturally separate. 
 
 The reproduction is by both the asexual and the sexual 
 ways. The asexual multiplication occurs in the earlier 
 part of the season. A flagellated gonidial cell divides 
 and subdivides into many parts, which escape into the 
 interior of the mother colony, where they unite to form 
 a new colony. 
 
 The sexual multiplication occurs late in the season. 
 Some of the flagellated cells develop into sperm cells, the 
 male gametes ; others develop into germ cells, the female 
 gametes. Both germ cells and sperm cells may be pro- 
 duced by the different differentiation of the flagellated 
 cells of the same colony, or they may be formed on dif- 
 ferent plants. When the germ cells have matured, they 
 are loosened from their positions in the shell of the colony 
 and pass into the hollow interior. In the sperm cells a 
 great many antherozoids or minute cells provided with 
 flagella are developed. These are set free by the break- 
 ing down of the wall of the cell in which they are formed, 
 and, swimming about, find their way into the interior of 
 the colonies containing the germ cells, which they meet 
 and fertilize. There results a resting spore with a thick 
 cell wall. After a period of rest, the resting spore, when 
 favorable conditions exist, resumes active life. Its pro- 
 toplasm breaks up into a great many small cells which 
 assume the spherical form and grow to be a full-sized 
 colony. 
 
THE ALG^E. 81 
 
 References for Reading. Carpenter's "The Microscope," pp. 479- 
 485 ; Goebel's " Classification of Plants," pp. 34-38 ; Bennett and 
 Murray's "Cryptogamic Botany," pp. 292-295; Parker's "Elementary 
 Biology," pp. 267-270 ; Sachs' " Physiology of Plants," pp. 728-730 ; 
 Vines' " Text-Book of Botany," pp. 237, 238. 
 
 The Protococcaceae. A large number of primordial 
 plants are included in this class ; but, inasmuch as their 
 life histories are only imperfectly known, it is not certain 
 that plants described under different names are not dif- 
 ferent forms of the same plant. In some plants no alter- 
 nation of generations from gametophyte to sporophyte is 
 known ; in other cases such an alternation is distinct. 
 
 Among the most common plants are the different forms 
 of Protococcus. The commonest of these is Protococcus 
 viridis. Protococcus pluvialis is a form containing enough 
 of a red pigment to give a decided red spot to each cell; 
 it is found in stagnant rain water. Protococcus nivalis, 
 or red snow, is the interesting plant that sometimes coats 
 the snow with red in a single night 
 in the higher latitudes and on the 
 mountains. 
 
 Other common forms are Chloro- 
 coccus, occurring in small aggre- 
 gations of cells, each of which is 
 surrounded by a comparatively thick 
 envelope of a gelatinous nature , Ra- FlG . 38. _ scenedesmm ob- 
 vhidium, occurring as long, slightly tys ' us Me > T - ( x 400. ) 
 
 e (From Bennett and Mur- 
 
 curved cells pointed at each end, ray .) 
 
 either singly or in small groups, with FlG - 39 - - Kaphidium fai- 
 
 6 J catum Ktz. ( X 800. ) 
 
 the Cells Crossing One another at (From Bennett and Mur- 
 
 their middle portions ; Scenedesmus, ray ^ 
 occurring as crescent-shaped cells, usually in groups of four, 
 not crossing one another. Tetraspora, as the name im- 
 plies, occurs in groups of four cells, which closely resemble 
 the nonmotile cells of Protococcus, but are imbedded in 
 
 CLARK'S BOT. 6 
 
82 
 
 PRACTICAL BOTANY. 
 
 I o 
 
 QG 
 
 an abundant gelatinous substance. This plant shows finely 
 the typical multiplication by cell division. The hyaline 
 
 envelope holds the cells in posi- 
 tion, and besides single cells, two, 
 
 four, and eight celled colonies 
 are arranged with great regu- 
 larity. Tetraspora may be found 
 on the bottom and on rocks in 
 clear, swift-running streams. 
 
 Pediastrum occurs in colonies 
 made up usually of sixteen cells. 
 These form a flat disk which 
 
 floats on the water. 
 BO 
 
 FIG. 40. Tetraspora lubrica. 
 The transparent gelatinous 
 substance which surrounds 
 the cells and holds them in 
 position is not shown in the 
 figure. (From Gray.) 
 
 Hydrodictyon, or the 
 Water Net, is common 
 in some places. It at- 
 tains a considerable size, 
 sometimes being six or 
 seven inches in diame- 
 ter. It is made up of 
 a green open network 
 of filaments or tubular 
 cells. 
 
 The asexual reproduc- 
 tion is brought about by 
 the formation of a great 
 number of swarm spores 
 in certain of the tubular 
 cells. If the cell is ob- 
 
 FiG.41. Pediastrumgranulattim. (X400.) 
 A, a disk of cells adhering to one an- 
 other ; at f/, the innermost layer of the 
 wall of a cell is just issuing from the cell, 
 and contains the daughter cells formed 
 by division of the green protoplasm ; at 
 t, various states of division of the cells ; 
 sp, slits in the walls of cells which have 
 discharged their contents. B, the inner 
 lamella of the wall of the mother cell 
 disengaged from the cell and much en- 
 larged ; b contains the daughter cells 
 #, which are in lively swarming motion. 
 C, the same family of cells four hours 
 and a half after its birth; four hours 
 after the small cells have come to rest 
 they have arranged themselves into a 
 disk, which is already beginning to de- 
 velop into such a one as A. (From 
 Goebel, after A. Braun.) 
 
THE ALG^E. 83 
 
 served at the right time, these swarm spores may be seen 
 in active motion. The motile condition does not last long, 
 but the spores arrange themselves in a methodical way in 
 the cell. The cell wall now breaks down, and the colony 
 of little cells develops into a full grown Water Net, 
 which escapes through the gelatinous wall of the mother 
 colony. 
 
 There is also a sexual method of reproduction. Enor- 
 mous numbers of microzoospores are formed in certain of 
 the tubular cells of the mother colony. By the breaking 
 down of the cell wall, these microzoospores escape. Each 
 has a red spot known as the eye spot. Each also has 
 four flagella. After a period of motility, they come to- 
 gether in pairs and form green zygospores enveloped with 
 a wall of cellulose. This is the resting spore. It closely 
 resembles the resting spore of Protococcus. Buried in the 
 mud at. the bottom of ponds and streams, these resting 
 spores retain their vitality against drought for a long 
 time, but will not endure exposure to strong light. 
 When the conditions are again favorable for growth, the 
 endochrome, or colored contents of the spore, separates 
 into either two or four parts, the cellulose wall breaks 
 away, and the newly formed zoospores work their way 
 out of the cell by means of the two flagella with which 
 each is provided. They are not very active. They soon 
 become angular in shape, in which condition they rest for 
 a time. They then divide and subdivide, forming numer- 
 ous microzoospores, which are active for a time. These 
 then arrange themselves in the net form, develop a new 
 gelatinous covering, and grow very rapidly into a full 
 sized Water Net. The alternation of generations is clearly 
 seen in Hydrodictyon. The plant itself is the gameto- 
 phy te ; the resting zygospores and the angular resting 
 spores represent the sporophyte. 
 
 The other plants of this class are not so abundant as 
 
84 PRACTICAL BOTANY. 
 
 Protococcus, and yet they are frequently found in gather- 
 ings from still water. 
 
 References for Reading. Bennett and Murray's " Cryptogamic 
 Botany," pp. 296-298; Carpenter's "The Microscope," pp. 495-498; 
 Goebel's "Classification of Plants," pp. 39-41. 
 
 PKOTOCOCCUS. PRACTICAL STUDIES. 
 
 Protococcus viridis is abundant on the north side of 
 old unpainted buildings and fences and on trees, forming 
 a very noticeable green incrustation ; it is especially dis- 
 tinct in wet weather. It may be obtained for study at 
 any season of the year from these sources. It also fre- 
 quently occurs during hot 
 weather in abundance in 
 stagnant pools of water. 
 
 1. Place a quantity of 
 Protococcus in alcohol for 
 |c several hours and observe 
 the yellowish-green color 
 \ imparted to the alcohol 
 |) by the chlorophyl. Mount 
 Sfy some of the cells so 
 r yj treated and observe that 
 the color has been en- 
 
 FIG. 42. Protococcus in the vegetative tirely removed. 
 
 condition, showing the mode of multi- 2. Mount a little fresh- 
 plication by cell division. 
 
 ly gathered Protococcus 
 
 in water. Notice that while many cells occur singly, others 
 occur in variously arranged groups. (See Fig. 42.) The 
 positions of the cells in groups show that the organism is 
 reproduced by cell division. Observe a reddish spot or 
 tint in many of the cells. Hsematococcus, a form of Pro- 
 tococcus found in stagnant rain water, receives its name 
 from the abundance of this red pigment. The chlorophyl 
 
THE ALG^E. 85 
 
 is collected in masses scattered through the cells the 
 chlorophyl bodies or chromatophores. Draw a single cell 
 and a group of cells, showing the minute structure. 
 
 3. Run a little iodine solution under the cover glass ; 
 the cell contents take a yellowish-brown color, showing 
 that protoplasm is present. A nucleus containing a 
 nucleolus can be seen in each cell unless the iodine solu- 
 tion is too strong and gives too intense a coloration. 
 The cell wall is unaffected by the iodine. Draw and 
 compare with drawing under Number 2. 
 
 4. Run sulphuric acid into the preparation that was 
 stained with iodine in Number 3. The cell wall turns 
 blue or violet. It is, therefore, composed of cellulose 
 such as is found in ordinary plants. Treat a fresh mount 
 with Schultze's solution, which should give the same 
 result. 
 
 5. Place pieces of bark bearing Protococcus in a glass 
 of water and expose to the sunlight for several days. 
 Observe that bubbles of gas rise from the water. It is 
 oxygen. Protococcus growing in pools t)f stagnant water 
 under favorable conditions gives off oxygen so freely that 
 a dense, frothy scum forms on the surface of the water. 
 If some Protococcus from such a pool be placed in a test 
 tube inverted over mercury, the oxygen gas may be col- 
 lected in such quantity that it may be tested by a spark. 
 
 6. Examine scrapings from the bark used in Number 5, 
 or Protococcus from a stagnant pool, under high power. 
 The mount will be found to be swarming with rapidly 
 moving organisms. These are the zoospores, or motile 
 forms of Protococcus. Large forms, megazoospores, and 
 small ones, microzoospores, will be present. It is hard to 
 persuade one's self that they are not animals. (Fig. 43, 
 B.) The motion is produced by the rapid lashing of the 
 water by two flagella, which extend from the anterior end 
 of the body of the organism. These can be seen under 
 
86 
 
 PRACTICAL BOTANY. 
 
 high power on motile forms that have come to rest. It is 
 much easier to see them in stained preparations. Run a 
 
 minute drop of iodine 
 solution under the cover 
 glass and watch its ap- 
 proach to the moving 
 organisms. As the or- 
 ganism dies the flagella 
 come into distinct view. 
 The flagella are believed 
 to be projections of the 
 protoplasm, and their 
 
 FIG. 43. - Protococcus. a, an encysted cell mo vements are produced 
 
 preparing to set free its four megazoo- 
 spores; b, a megazoospore or large mo- 
 tile form. 
 
 by the alternate con- 
 strictions of the proto- 
 plasm on their opposite sides. Draw a cell showing fla- 
 gella. The rapid movements of the motile forms, and the 
 fact that some species have contractile vacuoles, a char- 
 acteristic of the lowest forms of animals, have led to 
 doubts as to the classification of Protococcus. Some emi- 
 nent scientists class it as a plant ; others as an ' animal. 
 As already noted, the 
 possession of flagella in- 
 dicates close relation- 
 ship with the Volvoci- 
 nese. It is known that 
 after a time the motile 
 forms come to rest, draw 
 in their flagella, and be- 
 come invested with a 
 thick cell wall. They 
 
 are now resting spores. F IG- 44. Protococcus. An encysted cell 
 
 preparing to set free microzoospores. 
 
 6. Pmd large en- 
 cysted cells of Protococcus in which the cell contents are 
 broken up into separate parts. The megazoospores are pro- 
 
THE ALG^E. 
 
 87 
 
 duced by the division of the cell contents into four parts 
 (Fig. 43, a); the microzoospores by the division of cell 
 contents into many parts. (Fig. 44.) 
 
 References for Reading. Parker's " Elementary Biology," pp. 23- 
 35; Bidgood's "Elementary Biology," pp. 45-58; Dodge's "Practical 
 Biology," pp. 39-46 ; Huxley and Martin's " Practical Biology," pp. 
 389-395 ; Arthur, Barnes, and Coulter's " Plant Dissection," pp. 22-27 ; 
 Bower's " Practical Botany," pp. 439, 440 ; Bennett and Murray's 
 " Cryptogamic Botany," pp. 415-419 ; Carpenter's " The Microscope," 
 pp. 473-477. 
 
 The Confer voideae. The plants of this class are either 
 branched or unbranched filaments of cylindrical cells, or 
 
 FIG. 45. Chaetophora. The mode of branching is shown ; also the formation 
 of motile zoospores in maturing cells of the branches. 
 
 are cell surfaces. The sexual reproduction is in some 
 plants isogamous, i.e., it is between elementary cells that 
 cannot be distinguished as male and female. These cells 
 are ciliated and motile ; they may develop from any of the 
 cells. The asexual multiplication is by means of ciliated 
 zoospores, which may also form in any of the cells. These 
 plants grow by the transverse division of an apical cell or 
 
88 PRACTICAL BOTANY. 
 
 of cells that are intercalated in the filaments. Common 
 plants are Chcetophora and Cladophora. Cladophora, or 
 Water Flannel, is very common. It grows in running 
 water, forming long, dark-green stringy masses attached 
 to some fixed support at one end. It is made up of branch- 
 ing filaments, formed of elongated cylindrical cells, with 
 thick stratified walls. The branches develop from a sort 
 of bud formation near the top of the parent cell. As the 
 new branch forms, it becomes separated from the parent 
 cell by a partition wall that forms close to its base. The 
 cells are lined with protoplasm, and are also divided by 
 thin plates of protoplasm into a number of vacuoles. 1 
 
 ' 
 
 & 
 
 1 
 
 FIG. 46. Sea Lettuce (Ulva). 
 
 Another common plant, Sea Lettuce ( Ulva), is recog- 
 nized by its resemblance to the leaves of garden lettuce ; 
 it grows on the rocks and timbers in brackish and salt 
 water. 
 
 1 Chsetophora, or Cladophora, affords good material for Practical 
 Studies. 
 
THE ALG.E. 
 
 89 
 
 The asexual reproduction is by the successive division 
 and redivision of the cells in particular directions. In 
 outward appearance the plant resembles the higher Flower- 
 ing Plants, but a more minute examination reveals only 
 the simplest structure of aggregations of cells produced by 
 cell division. There is wanting entirely anything like 
 differentiation of the cells to form tissues of different 
 kinds. The cells are held in posi- 
 tion by an investing membrane, but 
 this membrane bears little resem- 
 blance to the epidermis of the higher 
 plants. Again, the different parts 
 of the plant differ as little in func- 
 tion as in form, any part being capa- 
 ble of reproducing the plant. 
 
 The sexual reproduction begins 
 by the division of the endochrome, 
 or colored contents, of some of the 
 cells into many portions. These 
 portions become motile, the cell wall breaks down, and 
 zoospores, which are provided with two or four flagella, 
 swim out into the water. The zoospores are of two sizes. 
 The larger ones, those having four flagella, are called mega- 
 zoospores ; the smaller ones are microzoospores. These 
 spores resemble very closely the motile forms of Proto- 
 coccus. 
 
 The megazoospores cling to some supporting object and 
 develop asexually by cell division into plants; the micro- 
 zoospores unite in pairs and form zygospores. The 
 zygospores grow into new plants. The zygospore repre- 
 sents the sporophyte; the ordinary form is the gameto- 
 phyte ; the megaspores are gonidia. 1 
 
 1 These spores are easily obtained by allowing some of the Sea Lettuce 
 to go to decay in a jar of sea water. Arrange Practical Studies of Sea 
 Lettuce. 
 
 FIG. 47. Sea Lettuce. 
 The individual cells are 
 shown held together 
 hy the investing mem- 
 brane. 
 
90 
 
 PEACTICAL BOTANY. 
 
 Other plants are heterogamous, i.e., the sexual repro- 
 duction is by the union of cells distinctly different from 
 each other. Important orders are the Sphceroplece, (Edo- 
 goniece, and Coleochcetece. 
 
 The (Edogonieae are to be looked for in stagnant and 
 flowing water, either in masses by themselves, or in asso- 
 
 48 49 
 
 FIG. 48. CEdogonium, showing splitting of cells and escape of the ciliated 
 
 zoospores. 
 FIG. 49. CEdogonium. a, zoospore; b-e, young plants. Magnified. 
 
 ciation with other plants. They do not usually grow 
 independently, but are supported by other plants, or are 
 attached to stones and the debris that accumulates in still 
 water. The color is green, or brownish-green. The en- 
 larged cells that they bear at intervals distinguish them 
 from other Green Algse. 
 
 The asexual reproduction of GEdogonium presents some 
 points of interest. Large oval zoospores are formed in 
 
THE ALGJR. 
 
 91 
 
 cells that develop near the upper ends of the branches. 
 When ripe, the cells split almost entirely across, the two 
 portions bend apart, and the zoospore, which has a number 
 of flagella at its smaller and colorless end, swims out. 
 After a period of activity, the zoospore becomes encysted 
 and attaches itself to some fixed object by its smaller end, 
 which becomes disk-shaped and acts as a sucker. The 
 larger end then grows by 
 the usual process of cell 
 division into a new plant. 
 (See Fig. 49.) 
 
 The zoospores of some 
 species develop in another 
 way. These zoospores, 
 which are smaller than the 
 common ones, affix them- 
 selves by their disk-shaped 
 ends to filaments bearing 
 oogonia. Here they de- 
 velop into filaments of a 
 few cells, the end cell be- 
 coming an antheridium, 
 which liberates anthero- 
 zoids to fertilize the eggs 
 in the oogonia. 
 
 In the sexual reproduc- 
 tion the OOgOnia develop FIG. 50. (Edogonium. 
 
 as enlarged cells at inter- 
 vals on the filament. The 
 antheridia develop in other cells on the same or on an- 
 other filament. Flagellated antherozoids, set free from 
 the antheridia, find their way to the ripened egg cells, de- 
 veloped in the oogonia, and fertilize them. The oospore 
 thus formed develops a thick reddish-brown wall and be- 
 comes a resting spore, which ultimately develops into a 
 
 a, filament; 6, 
 showing oogonium ; c, showing oogo- 
 nium and resting spore. Magnified. 
 
92 PRACTICAL BOTANY. 
 
 new plant. The oospore is the sporophyte; the plant 
 itself is the gametophyte. 1 
 
 References for Reading. Goebel's " Classification of Plants," pp. 
 44-46; Bennett and Murray's "Cryptogamic Botany," pp. 222-225, 
 Vines' " Text-Book of Botany," pp. 248, 249 ; Carpenter's " The Micro- 
 scope," p. 502. 
 
 The Coleochaeteae resemble the Red Seaweeds in a num- 
 ber of particulars, and are regarded by some as forming a 
 link between the Green and Red Algae. The color is 
 bright green. They may be found on the leaves and 
 stems of Water Lilies as disks one or two millimeters in 
 diameter. These disks are made up of branching rows of 
 cells radiating from the central part. If plants on which 
 they grow are placed in the light in glass vessels, they 
 often leave their positions and seek the sides of the con- 
 taining vessel. Examined under the microscope, numer- 
 ous hairs are found on the upper surface. 
 
 The asexual reproduction is by the formation of flagel- 
 lated zoospores. Any of the cells may produce these. 
 When the zoospore is ripe, a round opening forms in the 
 cell wall and the zoospore escapes. It then develops by 
 cell division into a new plant. 
 
 The sexual organs are produced in the terminal cells of 
 the branches. The end cells elongate, and the contained 
 protoplasm develops into the female reproductive organ, 
 or carpogonium, which is a specialized form of oogonium. 
 The antherozoids are produced in elongations from neigh- 
 boring cells. (See Fig. 51, og and an.) The fertilization 
 of the carpogonium by the antherozoid has never been ob- 
 served, but there is no doubt that it occurs. A covering 
 or pericarp now grows from the cells just below the fer- 
 
 1 CEdogonium is very common and is unusually good material for a 
 series of Practical Studies. Have on hand fresh gatherings ; also some 
 that is going to decay in a vessel of water. In this way the different 
 forms are almost sure to be found. 
 
THE AI.GM. 
 
 93 
 
 tilized carpogonium and envelops it. The pericarp and 
 carpogonium together constitute a spore fruit. This spore 
 fruit preserves the life of the plant until the following 
 season. Then, under favorable conditions, a number of 
 flagellated zoospores are formed and liberated, which, after 
 
 FIG. 51. A, part of a fertile thallus of Coleochsete pulvinata, showing the 
 aiitheridia, an, and the oogonia or carpogonia, og, in the process of for- 
 mation. (X 350.) B, ripe oogonium in its rind. C, germinating fructi- 
 fications of C. pulvinata, in the cells of which the swarm spores are formed. 
 D, swarm spores. (B-D X 280.) (From Goebel, after Pringsheim.) 
 
 a period of activity, develop by the asexual process into 
 new plants. The spore fruit is the sporophyte ; the plant 
 itself is the gametophyte. 
 
 References for Reading. Goebel's " Classification of Plants," pp. 
 46-48 ; Bennett and Murray's " Cryptogamic Botany," pp. 220-222 ; 
 Vines' "Text-Book of Botany," pp. 249, 250; Bower's "Practical 
 Botany," pp. 419, 420. 
 
 The Conjugatae. The sexual reproduction in this class 
 is by the formation of zygospores by the conjugation of 
 cells that are apparently just alike, i.e., it is isogamous. 
 The asexual reproduction is by the transverse fission of 
 
94 
 
 PRACTICAL BOTANY. 
 
 the cells. There is no 
 alternation of genera- 
 tions. The plant is the 
 gametophyte. The three 
 subdivisions are the 
 Desmidiece, Zygnemece, 
 and Mesocarpece. 
 
 The Desmidieae were 
 long classed as animals. 
 There is now considered 
 to be no doubt that 
 they belong to the plant 
 
 world. The Desmids are fresh-water plants. They are 
 microscopic in size and are of a vivid green color. They 
 
 FIG. 52. Desmids. a, Closterium lunula 
 in the incipient stage of transverse di- 
 vision; b,Euastrumdidelta. Two cells, 
 still adherent, which have resulted from 
 the division of a single cell. Magnified. 
 
 FIG. 53. A, Desmidium Swartzii Ralfs; B, Micrasterias rotata Grev. ; C, 
 Euastrum rostratum Ralfs; D, Cosmarium ccelatum Ralfs; E, Xanthi- 
 dium cristatum Breb.; F, Staurastrum Arachne Ralfs; G, Clo*terium 
 Dianse Ehrb. ; H, Docidium baculum Breb. (All from Bennett and 
 Murray, after Ralfs, and variously magnified.) 
 
THE ALG.K. 
 
 95 
 
 usually occur isolated, although they are sometimes seen 
 in short filaments, for they grow by the binary division of 
 the cells, and, as in the case of Protococcus and other one 
 celled plants, the cells sometimes remain adherent for a 
 time. The cells are bilaterally symmetrical, i.e., the two 
 halves of each cell are just alike. This fact helps to dis- 
 tinguish some forms from Diatoms. Another distinguish- 
 ing characteristic is the possession of projecting points 
 
 Fro. 54. Desmids. 1, Micrastenas papillifera ; 2, Micrastenas morsa ; 
 3, Cosmarium polygonwn; 4, Xanthidium aculeatum; 5, Staurastrum 
 furcatum ; 6, Euastrum oblongum ; 7, Penium Brebissonii ,- 8, Closterium 
 lunula ; 9, Xanthidium octocorne ; 10, two views of Staurastrum alternant ; 
 11, Cosmarium tetraophthalmum ; 12, Aptegonum desmidium. The figures 
 are all highly magnified. (Kerner and Oliver.) 
 
 or spines. These two facts and the bright green color 
 are great helps in their identification. 
 
 The cell contents are inclosed in a cellulose wall of con- 
 siderable firmness, and a more or less distinct gelatinous 
 covering envelops the cell wall. The protoplasm contains 
 chlorophyl and its product starch, and is arranged in bi- 
 laterally symmetrical patterns in the two halves of^ the 
 
96 
 
 PRACTICAL BOTANY. 
 
 cell, making the Desmids very attractive objects. The 
 ability which they possess to move about adds to the fas- 
 cination of their study under the microscope. 
 
 A great many varieties of Desmids are found. They 
 are to be looked for associated with plants growing in the 
 water and in the mud on the bottom of slow-flowing 
 
 FIG. 55. Zygospores of Desmids. A, Euastrum pectinatum Breb., showing 
 the zygospore and the empty cell envelopes of the cells that united. ( x 400.) 
 B, Peninm margarltaceum Breb. (X 300.) C, Closterium rostratvm Ehrb., 
 early stage, showing two cells just throwing out the connecting tube through 
 which the contents of the cells will pass to unite. (X 200.) D, Desmidium 
 Swartzii Ralfs. (X 600.) (All from Bennett and Murray, after Ralfs.) 
 
 streams, and in the shallow pools of somewhat clear water 
 in swamps and by the roadsides in spring and early sum- 
 mer. Water that is decidedly stagnant or that which 
 flows rapidly will not yield many forms. 
 
 The Desmids multiply asexually by the formation of a 
 partition that separates the two halves of an individual 
 
THK ALG^K. 97 
 
 cell. (See Fig. 52, a.) Each of these halves develops 
 until it is again bilaterally symmetrical, when the process 
 of cell division may be again repeated. 
 
 The Desmids are also reproduced in the sexual way by 
 the conjugation of two individual cells. (See Fig. 55.) 
 The zygospore thus formed grows by the process of cell 
 division. The conjugation seems to take place to give 
 new strength and vigor to the plant. 
 
 References for Reading. Carpenter's "The Microscope," pp. 509- 
 516; Bennett and Murray's " Cryptogam ic Botany," pp. 268-272; 
 Goebel's " Classification of Plants," pp. 50-52. 
 
 The Zygnemeae are very common and familiar objects, 
 some of them forming great masses upon the surface of 
 stagnant pools and ditches. They are commonly known 
 as pond scums. When in active growth the masses are 
 of a vivid though somewhat yellowish green. The plants 
 are unicellular, but as the cells are joined together by a 
 gelatinous covering, they form long unbranched filaments, 
 or linear aggregates. The gelatinous covering gives them 
 a slippery feeling when a mass is taken in the hand. 
 
 
 FIG. 56. Zygnema. a, a single cell ; 6, part of a filament whioh has resulted 
 from repeated transverse divisions of cells. Magnified. 
 
 There is a large number of species which are distin- 
 guished by the different arrangements of the chlorophyl 
 granules and bands. The disgusting masses of slimy ma- 
 terial are resolved into forms of great beauty when seen 
 under the microscope. In some species the chlorophyl 
 CLARK'S BOT. 7 
 
98 PRACTICAL BOTANY. 
 
 bodies tire scattered quite regularly over the entire sur- 
 face of the cell. In others they collect into two somewhat 
 starlike masses connected by a narrow band, giving a 
 shape resembling a dumb-bell. In others they collect into 
 spiral bands. The last forms are known as Spirogyra, 
 of which there are many varieties. 
 
 The asexual reproduction is by the transverse fission of 
 the cells. It is the usual process of the division of the 
 protoplasm and the formation of a cellulose wall across the 
 cell. The division takes place in the dark. It is best 
 observed by keeping the plants in a totally dark place for 
 some hours and then examining at once. This mode of 
 reproduction accounts for the long unbranched filaments. 
 
 The sexual reproduction may be seen at various seasons, 
 but is more likely to be met with in spring or in summer. 
 When the plant is at this stage, it takes on a brownish 
 color. The male and female filaments cannot be distin- 
 guished from each other, even under the microscope, but 
 when two filaments of opposite sexes happen to be in 
 proximity to each other, projections develop on the adja- 
 cent cell walls until they meet. (Fig 57, J?.) The cell 
 walls break away at the junction, and the contents of the 
 male cell are emptied into the other cell. A zygospore is 
 thus produced that becomes encysted and falls to the bot- 
 tom of the water, where, imbedded in the mud, it pre- 
 serves the life of the plant until the next season. On the 
 return of spring the zygospore grows in the asexual way 
 into a new filament. This is gonidial reproduction. 
 
 SPIROGYRA. PRACTICAL STUDIES. 
 
 1. Observe the light green color of the plant when seen 
 in mass. Notice that most species are slippery to the touch. 
 Place a little in water on a glass slip, hold the slip over a 
 white surface, and notice that the plants form fine uri- 
 
THE ALGJE. 
 
 99 
 
 FIG. 57. Spirogyra. .4, one whole cell and parts of two others, showing the 
 spiral chromatophore and, at d, a nucleus with distinct nucleolus suspended 
 in the center of the cell by bands of protoplasm. B, two filaments of a 
 different species of Spirogyra, showing three stages in the process of con- 
 jugation ; the cells dd are just preparing to connect by means of a tube 
 which forms itself from the projecting cell walls ; the cell g has given up the 
 greater part of its contents to the cell opposite ; at e a zygospore has formed 
 from the contents of the two opposite cells. C shows still a different kind 
 of chromatophore, and at e the formation of a zygospore by parthenogenesis. 
 
 branched filaments of uniform diameter ; use a hand mag- 
 nifier if necessary. 
 
 2. Let a quantity of Spirogyra stand in alcohol for a 
 short time. Then notice the color of the alcohol both by 
 reflected and by transmitted light. Describe the colors. 
 Notice also that the immersed filaments of the Spirogyra 
 are now colorless. 
 
100 PRACTICAL BOTANY. 
 
 3. Mount a very little of the Spirogyra in water. Ex- 
 amine with the low power and notice that each filament is 
 made up of cells which are just alike. The plant is uni- 
 cellular, although at first sight it seems to have many 
 cells. The long filaments are to be accounted for by the 
 fact that one mode of reproduction, the asexual, is by 
 the transverse division of the cells, the new cells being 
 held together, end to end, by a very delicate, gelatinous 
 membrane. Any of the cells may divide. 
 
 4. Examine with the high power. Notice the spiral 
 bands of chlorophyl the chromatophores or chlorophyl 
 bodies. The number of these bands differs in different 
 species. Several species may be present in the mount. 
 If not, mount specimens obtained from different localities 
 until a number of different forms of the chromatophores 
 have been observed. Draw three cells of each species 
 found. 
 
 5. Notice the roundish bright spots that occur at inter- 
 vals in the chromatophores. These are the pyrenoids. 
 
 6. Run iodine solution under the cover glass. Focus 
 upon filaments that are just beginning to take the stain. 
 If the Spirogyra has been in the sunlight for some time, 
 a ring of dark blue, almost black, particles will be seen 
 around each pyrenoid. These are starch granules. Keep 
 some Spirogyra in the dark for several hours. Test for 
 starch. Do you find it ? 
 
 The chromatophores of chlorophyl-bearing plants are 
 the laboratories in which the starch is manufactured. 
 Keep some Spirogyra for one or two hours in water that 
 has been boiled to expel the carbon dioxide. Test for 
 starch. Do you find it ? If so, is it as abundant as in 
 Spirogyra kept in water from which the carbon dioxide 
 has not been removed ? What conclusion do you draw 
 as to the necessity of carbon dioxide in the formation of 
 starch? Keep Spirogyra in ordinary water in the sun- 
 
THE ALGJE. 101 
 
 light ; notice bubbles of gas given off by the plant. This 
 gas is oxygen set free in the chemical changes that occur 
 in the formation of the starch. 1 ; i% V 
 
 In a vessel containing healthy Spirogyra ^rovYing^ki 
 Sachs' solution in the sunlight, arrangte a/feft&tAfte 'kO'C'oi-' 
 lect the gas given off. The tube is filled with the solu- 
 tion and supported bottom up with its mouth just below 
 the surface of the solution. Let the stem of an inverted 
 funnel rise into the tube, the flaring portion of the funnel 
 being in position to catch the bubbles of gas. Let the 
 apparatus stand until a quantity of the gas has collected, 
 agitating the Spirogyra below the mouth of the funnel 
 from time to time to dislodge the bubbles which cling to 
 the plant. Test the gas by introducing a spark on the 
 end of a splinter of wood. The spark glows more brightly, 
 or kindles into a flame, showing that the gas is oxygen. 
 
 7. Run glycerine under the cover glass of a specimen 
 that has been treated with iodine solution. Note that the 
 slightly stained protoplasm shrinks from the cell wall. 
 The cells may also be plasmolyzed by running ten per cent 
 salt solution under the cover. The protoplasm contracts 
 and the primordial utricle is brought into view. Notice 
 the large centrally situated vacuole. 
 
 A short piece of glass tubing closed at both ends and 
 covered with paper gives a good idea of the Spirogyra cell. 
 The paper represents the transparent cell wall ; the glass 
 represents the thin lining of protoplasm or primordial 
 utricle ; the hollow interior, which in the Spirogyra is, 
 of course, filled with cell sap, represents the vacuole. The 
 nucleus is suspended in the center of the vacuole. 
 
 8. Run solution of caustic potash under the cover glass. 
 This brings the cell wall into more prominent view. Trace 
 a filament to its end. Notice that the filament is of uni- 
 form width, with perhaps an occasional accidental enlarge- 
 ment or contraction, the cells being of the same shape with 
 
102 PRACTICAL BOTANY. 
 
 the exception of the end cell, which differs from the others 
 
 only in having its extremity more rounded. 
 
 .'9. Run* Schiiltee's solution under the cover glass of a 
 g fresh .mount. .NoUce and describe the effect on the cell 
 ; wall and ion -the "Cell' contents. 
 
 10. Find the nucleus in a fresh mount. In some spe- 
 cies the nucleus is very prominent ; in others it can be 
 made out only after special treatment. In difficult cases 
 leave some Spirogyra in a one per cent solution of picric 
 acid for several hours, wash out the acid in water, followed 
 with 35 per cent alcohol, stain in Grenadier's borax car- 
 mine, wash again in 35 per cent alcohol, and mount in 66 
 per cent glycerine. 
 
 By searching material from different localities, good 
 specimens are usually found which show the nucleus with- 
 out this special treatment. Draw a cell, showing all the 
 details of structure, especially the nucleus, nucleolus, and 
 the manner in which they are suspended in the center of 
 the cell by strings of protoplasm running to the pyrenoids. 
 (Compare Fig. 57, A and B.) Treat different mounts of 
 material showing the nucleus with iodine, alcohol, ten per 
 cent salt solution, and with different stains. 
 
 11. Find material in the conjugating condition. Here 
 again it may be necessary to search the material from 
 several localities. Find, if possible, specimens in which 
 the zygospores are formed in the cells of one of the fila- 
 ments, and others in which they are formed in the conju- 
 gating tubes between the filaments. Draw in detail 
 typical cases. 
 
 12. Try to find material in which the contents of the 
 cells of a filament have become aggregated into spores 
 without conjugating with the cells of another filament. 
 Such cases may be recognized by the fact that the cell 
 walls are still entire and show -no indications of having 
 given out conjugating tubes, or of having received such 
 
TIIK ALGJE. 
 
 103 
 
 tubes from another tilament. (See Fig. 57, (7, e.) These 
 spores are produced by parthenogenesis. 
 
 13. Place some freshly gathered vigorous Spirogyra in 
 a refrigerator over night. In the early morning examine 
 for the division of the cells by the asexual process. This 
 division takes place, under natural conditions, at about 
 the middle of the night. Cold delays the process. Make 
 drawings showing as many different stages as are found. 
 
 References for Reading. Parker's "Elementary Biology," pp. 149- 
 200; Goebel's "Classification of Plants," pp. 48-50; Bennett and 
 Murray's " Cryptogam ic Botany," pp. 264-266; Vines' "Text-Book 
 of Botany," pp. 244-246; Sachs' "Physiology of Plants," pp. 727, 
 728 ; Huxley and Martin's " Practical Biology," pp. 396-407 ; Arthur, 
 Barnes, and Coulter's "Plant Dissection," pp. 33-42; Bessey's "Essen- 
 tials of Botany," pp. 122, 123; Campbell's "Structural and Systematic 
 Botany," pp. 30-33; Dodge's "Practical Biology," pp. 51-61; Boyer's 
 "Elementary Biology," pp. 121-124; Strasburger and Hillhouse's "Prac- 
 tical Botany," pp. 207-209, 246, 247 ; Bower's " Practical Botany," pp. 
 442-446. 
 
 The Mesocarpeae are 
 distinguished from the 
 Zygnemese by the arrange- 
 ment of the chlorophyl 
 in straight bands in the 
 longitudinal direction of 
 the cell rather than in 
 spiral coils and dumb-bell- 
 shaped figures. The sex- 
 ual multiplication is by 
 a process of conjugation 
 similar to that of the 
 Zygnemese ; the asexual 
 reproduction is by the 
 separation and subsequent 
 fission of the cells of the 
 filaments, 
 
 FIG. 58. Mesocarpus. a, conjugating 
 cells ; 6, vegetative cells. 
 
104 PRACTICAL BOTANY. 
 
 References for Reading. Bennett and Murray's " Cryptogamic 
 Botany," pp. 260-263; Vines' "Text-Book of Botany," p. 246; Goe- 
 bel's " Classification of Plants," p. 49 ; Carpenter's " The Microscope," 
 p. 478 ; Campbell's " Structural and Systematic Botany," p. 33. 
 
 The Characeae or Stone worts. The Characese differ so 
 much from all the plants below them and from all those 
 above them that it is difficult to deter- 
 mine their position. Their place is far 
 from settled, and writers of the highest 
 authority differ in opinion in regard to 
 them. They rank decidedly higher in 
 complexity of structure than any of the 
 plants thus far considered. A large num- 
 ber of species is found in the various parts 
 of the world. Some occur in almost every 
 locality. The species are all comprised in 
 two genera, Chara and Nitella, which may 
 in general be distinguished by the fact 
 that a transverse section of the stem of 
 Nitella is like the section of a single hol- 
 low tube; a similar section of Chara is 
 like the section of a tube surrounded by a 
 number of smaller tubes. A surface view 
 of the portion of a stem of Nitella between 
 two nodes shows a single large cell ; a similar surface view 
 of Chara shows a number of cortical cells overlying the 
 large central cell. A few species of Chara do not have 
 the cortical cells. The leaflets are single celled in Chara ; 
 usually more than one celled in Nitella. The plants may 
 be found in sluggish fresh-water streams and in ponds. 
 They vary in color from a light to a very dark green. 
 They grow attached by rootlets to the mud on the bot- 
 tom. Some species grow only partly submerged ; others 
 are wholly covered by the water. The latter may be 
 looked for by raking the bottom of ponds in the shallow 
 
THE ALG^E. 
 
 105 
 
 water near the bank. The plant stem may be only a few 
 inches in length, or it may reach a length of some feet. 
 
 FIG. 60. Cham fragilis. E is a single leaf, consisting of one cell and show- 
 ing the neutral line ; the arrows show the movement of the protoplasm in 
 cyclosis. B is a ripening antheridium. A is an archegonium showing the 
 mature egg cell surrounded by spiral cells and surmounted by a crown of 
 cells. D is a manubrium with its surrounding cells. At C are represented 
 the filaments of cells in which the antherozoids are produced. F and G 
 show the ciliated antherozoids after they have been set free. The cortical 
 cells on the stem are not shown in the figure. All are highly magnified. 
 
 The diameter is seldom much greater than two or three 
 millimeters. 
 
 The leaves grow in whorls from points on the stem 
 called nodes. The lengths of stem between the nodes 
 
106 PRACTICAL BOTANY. 
 
 are called internodes. The stem also sends out branches 
 from the axils of the leaves at the nodes, and each branch 
 repeats the structure of the main stem. All the older 
 portions of the plants have the cell walls thickened by 
 deposits of carbonate of lime, which gives the plants their 
 common names, Stonewort and Brittlewort. The main 
 stem and each of the branches is tipped with an apical 
 bud, which is composed simply of the young cells that are 
 to develop into a new node and internode of the stem and 
 a new whorl of leaves. 
 
 The sexual reproductive organs are borne on the leaves 
 on the upper part of the plant. They are just visible to 
 the naked eye. The antheridium is spherical in shape, 
 and is of an orange-red color ; it grows on the under side 
 of the base of a bract or leaflet. (Fig. 60, B.) The arche- 
 gonium is oval in shape, of a dark green, brown, or black 
 color, and grows in the axil of the bract or leaflet, just 
 above an antheridium. (Fig. 60, A.) Both are modified 
 leaves. In one species, Ohara crinita, the archegonium is 
 capable of germinating without having been fertilized by 
 the antherozoids, i.e., the plant is reproduced partheno- 
 genetically. 
 
 No asexual reproduction by spores is known to exist in 
 any of the Characese. There is therefore no alternation 
 of generations. The plant is the gametophyte. A vege- 
 tive reproduction by means of branches which fall off 
 from the mother plant and grow into new plants occurs, 
 
 THE CHARACE.E. PRACTICAL STUDIES. 
 
 1. Detach an entire plant of Chara or Nitella from the 
 tangled mass in which it grows. Place it in a shallow dish 
 of water. Examine with a magnifying glass. Find the 
 rhizoids or rootlets. Do you find them at more than one 
 node ? Do you find them on the internodes ? Are they 
 
THE ALG^E. 107 
 
 of the same color as the stem ? Count the leaves in each 
 whorl. Is the number the same ? State what number 
 you find. Measure the lengths of the internodes. Are 
 they all of the same length ? Describe the reproductive 
 organs as they appear under the hand magnifier. Also 
 the apical buds. Draw the entire plant on as large a 
 scale as your notebook allows. 
 
 2. Obtain, if possible, plants of both Chara and Nitella. 
 Examine under the low power. Draw and label an inter- 
 node of each. Cut cross sections of both, holding the 
 specimen between two pieces of pith. Draw and label 
 a cross section of each. Examine any of the internodes 
 of a Nitella plant or one of the youngest leaves of Chara. 
 Are the chlorophyl bodies arranged in any definite way ? 
 Notice the neutral zone that contains no chlorophyl bodies. 
 In what direction does it extend? (See Fig. 60, E.~) 
 
 3. Under both low and high powers examine any of 
 the cells of Nitella or the youngest leaves of Chara for 
 cyclosis or rotation of the protoplasm. Handling the 
 specimen often causes the cyclosis to stop. In that case, 
 place plenty of water under the cover glass and put the 
 slide in a warm place for fifteen or twenty minutes, and 
 the cyclosis will again start. Focus into the cell below 
 the chlorophyl bodies. Draw a cell, showing the neutral 
 line, and indicate the direction of the currents by arrows. 
 From time to time the currents stop and after an interval 
 begin in the opposite direction. The cells of Nitella show 
 cyclosis better than any other known plants. 
 
 4. Keep some Chara or Nitella in alcohol until the 
 chlorophyl has been removed. Mount in alcohol and run 
 iodine under the cover glass. Is starch present ? In 
 another mount of fresh or alcoholic material determine 
 whether the cell walls are composed of normal or fungous 
 cellulose. 
 
 5. Examine fresh young terminal leaves of Chara or 
 
108 PRACTICAL BOTANY. 
 
 Nitella in water. Find chlorophyl bodies that are under- 
 going division ; they are recognized by constrictions at 
 the middle of the cells. Draw. 
 
 6. Cut off the end of a young internodal cell and press 
 the protoplasmic contents out into a drop of water on a 
 glass slip. Examine with high power. Describe the 
 changes that occur as the cell contents mix with the 
 water. Do you recognize starch granules ? Use iodine 
 solution if necessary. Notice also numerous large and 
 small masses of proteinaceous matter floating in the 
 colorless protoplasm. Do not confound these with the 
 chlorophyl bodies. 
 
 7. Dissect a terminal bud with needles and mount in 
 water. Run iodine solution under the cover glass. Find 
 the apical cell. Has it more than one nucleus ? Observe 
 the cells below the apical cell and see, if you can, how the 
 nodes, internodes, and leaves result from the division and 
 subdivisions of the apical cell. Draw. The apical cells 
 of Chara and Nitella have been favorite objects for the 
 study of the division of the cell on account of the large 
 nuclei and the clearness of the successive steps in their 
 differentiation. The plant increases in length by the 
 division of these apical cells. In this respect there is a 
 decided advance over plants in which any of the cells 
 may divide. 
 
 Place a healthy plant in water in the sunlight. Notice 
 the number and measure the lengths of the internodes. 
 After some days notice if there has been any increase in 
 the number of internodes and in their lengths. 
 
 8. Study the antheridium. It may be recognized by 
 the naked eye or a magnifying glass as an orange-colored 
 sphere. (Fig. 60, .#.) The color is due to a pigment which 
 results from the ripening of the chlorophyl bodies that line 
 the inner surface of the cells. Notice under high power 
 several circular cells on the surface. There are eight of 
 
THE ALG^E. 109 
 
 these on each antheridium. Each of these circles is the 
 outer end of a cylindrical cell which extends inward 
 towards the center. These eight cylindrical cells are the 
 manubria or handles. Draw an antheridium, taking pains 
 to represent clearly the circular cells and the polygonal 
 cells which surround them. 
 
 By pressure on the cover glass crush an antheridium. 
 Find a manubrium. (Fig. 60, D.) On its inner end 
 notice an irregularly spherical cell, the capitulum ; smaller 
 spherical cells, the secondary capiiula, project inward from 
 the capitulum, and from each of these grow long filaments 
 composed of minute cells. (Fig. 60, (7.) Each of these 
 cells produces an antherozoid (Fig 60, .F), a motile cell 
 which bears two long flagella at its anterior pointed 
 end. Each antheridium bears between 20,000 and 40,000 
 of these antherozoids. If the antheridium is of the right 
 degree of maturity, the antherozoids can be seen in the 
 cells of the filaments, or swimming about free in the 
 water. Find them if possible. Stain with iodine after 
 they are found, to bring their very delicate transparent 
 flagella into view. Under the cover of another mount 
 run a very little gentian violet and look for the anthero- 
 zoids in the cells of the filaments. This treatment will 
 also frequently show the divided nuclei in cells near the 
 ends of the filaments that are undergoing division. Draw 
 all that you have seen. 
 
 9. Study the archegonium. This also may be recog- 
 nized by the naked eye or magnifying glass as an ovoid 
 brown, green, or black body situated in the axils of the 
 leaflets or bracts. (Fig. 60, A.) Find archegonia in dif- 
 ferent stages of development. Under high power notice 
 the spiral cells that envelop the egg cell. Focus below 
 the spiral cells on a young archegonium and make out all 
 you can of the egg cell. Notice the crown of cells at the 
 apex of the archegonium. If possible, examine the crown 
 
110 PRACTICAL BOTANY. 
 
 in both Chara and Nitella and state how many cells com- 
 pose it in each. When the egg cells are ready for fer- 
 tilization, antherozoids, which have been set free in the 
 water by the ripening of the antheridium, swim to the 
 crown, find passage down through a central opening be- 
 tween its cells, enter, and fertilize the egg. The egg now 
 matures, protected by its covering of cells. In time the 
 archegonium drops off from the mother plant, sinks to the 
 bottom in situ, or is carried by currents to other localities. 
 When the conditions are again favorable, it germinates 
 and produces a new plant. Draw an archegonium. 
 
 References for Reading. Bidgood's "Elementary Biology," pp. 
 85-111; Parker's "Elementary Biology," pp. 206-220; Bennett and 
 Murray's " Cryptogamic Botany," pp. 173-183 ; Goebel's " Classifica- 
 tion of Plants," pp. 52-64 ; Carpenter's " The Microscope," pp. 505- 
 509 ; Sachs' " Physiology of Plants," pp. 95, 96, 453, 454 ; Strasburger 
 and Hillhouse's "Practical Botany," pp. 37, 202 f, 254 g; Vines' 
 " Text-Book of Botany," pp. 251-255 : Huxley and Martin's " Practi- 
 cal Biology," pp. 430-442 ; Dodge's "Practical Biology," pp. 273-284; 
 Boyer's " Elementary Biology," pp. 128-133 ; Campbell's " Structural 
 and Systematic Botany," pp. 37-40 ; Bessey's " Essentials of Botany," 
 pp. 180-182; Bower's "Practical Botany," pp. 409-418. 
 
 CLASS II. The Brown Algae (Phaiophyceoe). A decided 
 advance in the tissues of the plant thallus arid the position 
 of the cilia on the sides of the base of the pointed end of 
 the zoospores, are characteristics which distinguish the 
 Brown Algae from the Green Algae. Chlorophyl is pres- 
 ent, but is rendered invisible by the presence of a brown 
 coloring matter, pJiycophcein, which is probably a dif- 
 ferentiation product from the chlorophyl. The fertili- 
 zation is isogamous in the lowest plants ; in the higher 
 forms it is oogamous. In many of the plants of this 
 group, however, the process of the sexual fertilization is 
 still unknown. There are two subdivisions based on the 
 character of the swarm spores, the Phceosporece and the 
 
THE ALG^E. Ill 
 
 Fucacece. In the former the swarm spores are of the same 
 size and form, though it is believed that some are asexual 
 propagative cells and others are sexual cells or gametes, 
 which conjugate. In the Fucaceae the male elements are 
 minute antherozoids, each provided with a pair of cilia; 
 the female elements are comparatively large oospheres 
 not provided with cilia. 
 
 In some cases there is a distinct alternation of genera- 
 tions ; in others there is none or it is doubtful. 
 
 The Phaeosporeae. The Kelp and Laminaria of the 
 seashore are well-known plants, many of them showing a 
 considerable degree of differentiation. The differentia- 
 tion of structure is shown- in the stemlike stalk and in 
 rootlike appendages that enable it to cling to some fixed 
 support. In the Pacific and South Atlantic oceans, a 
 giant kelp is found, of 800 or 900 feet in length. 
 
 Zoospores provided with two flagella each are known ta 
 be formed in some of the cells, but the union of the 
 zoospores to form zygospores from which new plants can 
 develop has been observed in only a few cases. 
 
 The Fucaceae or Rockweeds. These plants are all 
 inhabitants of the salt water. The ordinary Rockweeds 
 are types. They grow attached to the rocks by a disk- 
 like expansion of the root ends, so to speak. The stem 
 divides and develops into expanded portions which resem- 
 ble leaves, being flat, and possessing an enlargement like 
 a midrib. The plants have at intervals air sacs, which are 
 evidently nature's provision for buoying them up. 
 
 The only approach to asexual reproduction in Rock- 
 weeds is. the formation of little shoots on the edges of the 
 larger branches. It is possible that these separate from 
 the parent plant and grow into new plants ; this, however, 
 is not established, and asexual reproduction is not posi- 
 tively known to occur. The alternation of generations is 
 therefore unknown. 
 
112 
 
 PRACTICAL BOTANY. 
 
 FIG. til. Fucus vesiculosus. An entire frond is represented, the lower part 
 at C, the upper part at D. At C is seen the disk by which the plant was 
 attached to a rock or other support. At M are seen the enlarged ends of 
 branches bearing the conceptacles in which the reproductive cells are pro- 
 duced. At 6, antheridia with paraphyses are represented ; at c, an oogo- 
 nium with paraphyses ; at d, a ripened oogonium with egg cells ready to 
 burst forth. 
 
 The sexual reproduction is better understood. Certain 
 branches become swollen at the ends. In these enlarge- 
 ments the sexual organs develop. The antheridia may be 
 
THE ALG^E. 113 
 
 seen in sections through these enlargements as orange- 
 yellow masses ; the oogonia are borne either in the same 
 cavities or in cavities on other plants. The eggs that 
 develop in the oogonia are set free into the water, and 
 the flagellated antherozoids, liberated from the antheridia, 
 find and fertilize them. This, at least, is the belief ; but 
 the actual entrance of the zoospore into the egg has never 
 been observed. After fertilization, the egg secretes a wall 
 about itself, enlarges, attaches itself to some fixed support, 
 and grows into a fully developed plant. 
 
 FUCUS VESICULOSUS. PRACTICAL STUDIES. 
 
 Fucus vesiculosus, or Bladder Wrack, is the most widely 
 distributed of the Rockweeds. The frond or thallus is 
 wide and flat. The air sacs, which are conspicuous, are 
 arranged in pairs on the distinctly dichotomously divid- 
 ing frond. (Fig. 61, (7andD.) 
 
 1. Observe, if possible, the plants growing in their 
 natural positions attached to the rocks. Draw an entire 
 plant, labeling the attachment disk, stipe, frond, midrib, 
 air sacs, and the enlarged ends of branches which bear 
 the conceptacles containing sexual reproductive organs. 
 
 2. Thoroughly dry and pulverize some of the Rock- 
 weed, and place it in cold fresh water. The water soon 
 takes on a brownish color, due to the special pigments 
 which give the brown and olive colors to the plant. 
 
 Place pieces of fresh Rockweed in alcohol. The alcohol 
 dissolves the chlorophyl and assumes a yellowish-green 
 color. 
 
 3. Place a piece of the frond that has been preserved 
 in alcohol between two pieces of pith and cut thin trans- 
 verse sections. Mount in glycerine. Notice the differ- 
 ences between the centrally situated medullary cells and 
 the cortical cells. Can you make out an epidermis ? The 
 
 CLARK'S BOX. 8 
 
114 PRACTICAL BOTANY. 
 
 increase in thickness of the frond is effected by the divi- 
 sion of the outer cells of the cortex. Draw the entire 
 section. Test for starch. Is it present ? Run Schultze's 
 solution under the cover of another preparation. Are 
 the cell walls composed of normal cellulose ? 
 
 4. With the hand magnifier notice the distinct notch 
 in the ends of the branches that do not bear concepta- 
 cles, i.e., those that are not swollen. Then make longi- 
 tudinal thin sections through the notches, using alcoholic 
 material. Mount in glycerine. In some of the sections 
 a well-defined four-sided apical cell will be found, sur- 
 rounded by cells which have had their origin in the seg- 
 mentation of the apical cells. Some difficulty will be 
 experienced in finding the apical cell. It is by this form 
 of cell division that the plant increases in length. Ob- 
 serve also in this section the distinction of medullary, 
 cortical, and epidermal cells. 
 
 5. Make sections, both transverse and longitudinal, 
 through the air sacs. (Fig. 61, _Z?.) Do you find the 
 same distinctions of medullary, cortical, and epidermal 
 tissues that you have already found in the transverse and 
 longitudinal sections of the frond? Do the structures 
 found help you to judge how the air sacs were formed ? 
 
 6. Examine with a hand magnifier the conceptacles on 
 branches that were gathered at high tide and have hung 
 about six hours in a cool place. The male and female 
 conceptacles are borne on different plants in the case of 
 Fucus vesiculosus. The male are distinguished from the 
 female by an orange-colored exudation. Notice the warty 
 appearance of the conceptacles. (Fig. 61, M.) Also the 
 ostiole, or stoma, at the apex of each wart. (This is seen 
 in section in Fig. 62, 1.) In many cases tufts of delicate 
 hairs project from the ostioles. 
 
 7. Using alcoholic material, make thin transverse and 
 longitudinal sections through a branch bearing male con- 
 
FIG. 62. 1, longitudinal section through a male conceptacle of Fucus vesicu- 
 losus, showing the cavity nearly filled with antheridia surrounded by para- 
 physes ; 2, some of the antheridia and paraphyses more highly magnified ; 
 3, ripened antheridia allowing the antherozoids to escape; 4, an egg cell 
 like those in Fig. 63, 4, surrounded by antherozoids. All much magni- 
 fied. (From Kerner and Oliver, after Thuret.) 
 
 115 
 
116 PRACTICAL BOTANY. 
 
 ceptacles. (Fig. 62.) Examine with low power. What 
 is the shape of the conceptacles ? Do you find numerous 
 hairs or paraphyses in the conceptacles ? Do they in some 
 cases project through the ostiole ? Are they branched or 
 unbranched ? Are they unicellular or multicellular ? Draw 
 a conceptacle, showing all you can see under low power. 
 Find small ovoid antheridia borne on the paraphyses, 
 using the high power. (These are seen in Fig. 61, 6, and 
 Fig. 62, 2.) Draw several antheridia, showing their 
 attachment to the paraphyses. Can you distinguish the 
 antherozoids in the antheridia ? Mount in sea water a 
 drop of the orange-colored exudation mentioned above 
 and examine it for moving antherozoids. (See Fig. 62, 3 
 and 4.) These observations are difficult. 
 
 8. Examine under low power transverse and longitudi- 
 nal sections through an alcoholic branch bearing female 
 conceptacles. (See Fig. 63.) What is the shape of the 
 conceptacles? Notice the oogonia. (Fig. 61, c and d, 
 and Fig. 63, 2.) In what part of the conceptacle are 
 they located ? How do they compare in size and shape 
 with the antheridia ? Both the oogonia and the antheridia 
 are modifications of paraphyses. Draw the conceptacle, 
 showing all you can see under low power. 
 
 Examine the oogonia under high power. Notice the 
 transparent covering. Test it with Schultze's solution. 
 Is it cellulose ? In material collected in autumn, find 
 oogonia undergoing division into oospheres. (Fig. 61, 
 cZ, and Fig. 63, 2, 3, and 4.) Make out, if you can, the 
 number of the oospheres. If material bearing the motile 
 antherozoids has also been found, mount some of the 
 antherozoids and oospheres in the same drop of water 
 and watch for the entrance of the antherozoids into the 
 oospheres. Draw. Does each oosphere have a nucleus ? 
 
 References for Reading. Goebel's "Classification of Plants," pp. 
 65-73; Carpenter's " The Microscope," pp. 554-559 ; "Vines' Text-Book 
 
THE AL6JE. 
 
 117 
 
 of Botany," pp. 263-267 ; Bennett & Murray's " Cryptogamic Botany," 
 pp. 228-236; Dodge's "Practical Biology," pp. 285-296; Bower's "Prac- 
 tical Botany," pp. 391-408 ; Campbell's " Structural and Systematic 
 Botany," pp. 42-48; Bessey's "Essentials of Botany," pp. 144-147. 
 
 FIG. 63. 1, longitudinal section through a female conceptacle of Fucus vesicu- 
 losus, showing oogonia preparing for division and surrounded by paraphy- 
 ses ; 2, an oogonium and several paraphyses more highly magnified ; 3, an 
 oogonium with the egg cells all ready to burst through the surrounding 
 membrane ; 4, the same after the membrane has burst and set the egg 
 cells free. All much magnified. (From Kerner and Oliver, after Thuret.) 
 
118 PRACTICAL BOTANY. 
 
 CLASS III. The Red Algae (Rhodophycece or Floridece). 
 These are for the most part the Red Seaweeds. A few 
 live in fresh water. They are chlorophyl-bearing, but the 
 green is obscured by the presence of a red coloring matter, 
 phycoerythrin. In some instances the color is brown, 
 yellow, dull white, or even green. The Red Algae are 
 distinguished from the Brown and Green Alga3 by the 
 higher development of the sexual reproductive organs. 
 The higher differentiation and development of the vegeta- 
 tive organs also place these plants above all other Algse 
 in the classification. 
 
 The reproductive processes in the Red Algse resemble 
 very much those already described for the Coleochgetese, 
 though they are in general of a higher order of develop- 
 ment. There are, of course, variations in the different 
 species. The asexual reproduction is by the formation of 
 nonmotile tetraspores in the terminal cells of branches or 
 in any of the cells of special branches. The sexual repro- 
 duction, which has been less frequently observed, does 
 not usually occur on plants that reproduce themselves 
 asexually, though in some instances both modes of repro- 
 duction have been known to occur in the same individuals. 
 The alternation of generations is well marked in many 
 plants ; the ordinary form is the gametophyte. 
 
 The plants may be either monoecious or dioecious. 
 The antheridia may consist of a single cell each, or they 
 may consist of a number of cells. The antheridia do not pro- 
 duce true antherozoids, but rather naked masses of proto- 
 plasm without cilia or other means of locomotion. They 
 are transported by currents in the water and, as there is 
 reason to believe, by fish which feed on seaweeds, until 
 they come in contact with the female organ of reproduc- 
 tion, the procarp, which in many respects resembles the 
 pistils of the Flowering Plants. The result of the fer- 
 tilization of the procarp is a carpospore, but the variations 
 
THE ALGJE. 
 
 119 
 
 and complications in the process are so many that they 
 cannot be detailed here. 
 
 Many of the Red Algte are of great beauty on account 
 of their red and purple colorings, and on account of their 
 delicate, graceful forms. The Red Algae grow in the 
 ocean in a somewhat narrow border along the coasts. 
 Many forms grow at some depth in the water. These 
 deep sea forms are often the most delicate and beautiful. 
 The seas in warmer climates abound in these plants, but 
 the waters of colder regions, even within the Arctic circle, 
 produce some forms. 1 
 
 References for Reading. Vines' " Text-Book of Botany," pp. 267- 
 272 ; Goebel's " Classification of Plants," pp. 73-80 ; Carpenter's " The 
 Microscope," pp. 559-561 ; Bennett & Murray's "Cryptogamic Botany," 
 pp. 191-203. 
 
 1 In places where the Red Algae are easily obtainable, Practical Studies 
 may be arranged on many different forms. 
 
V. 
 
 THE FUNGI. 
 
 The Fungi include a very large number of chlorophyl- 
 less saprophytic or parasitic plants. A saprophytic plant 
 is one that lives by the absorption of decaying organic 
 matter ; a parasite lives on other living organisms, robbing 
 them of the nourishment they have prepared for them- 
 selves. In some cases the same organisms may live either 
 as saprophytes or parasites. Some of the Fungi are organ- 
 isms of very low development ; in others the development 
 has reached a considerable degree of complication. In the 
 higher forms the development of mycelial rhizoids is 
 marked ; these are the fine threads of the mycelium of the 
 plant which permeate the substratum on which the plant 
 grows and absorb from it nutrient materials; in many 
 cases this mycelium acts as a ferment on the substances in 
 the soil, causing their decomposition and preparing them 
 to become food for the plant. There is in no case a tend- 
 ency to the formation of leaves. The most striking char- 
 acteristic of these plants is the absence of chlorophyl ; this 
 fact alone, however, does not determine their separation 
 into a subdivision by themselves. That separation is based 
 rather upon morphological characteristics. The plant 
 body is a thallus that develops by apical growth into root 
 hyphce, the mycelium, or branches below the surface of the 
 substratum on which the plant grows, and shoot hyphce, or 
 branches above the surface. A few forms that do not 
 develop by apical growth, such as the yeast plants, for 
 example, are classed as Fungi on account of resemblances 
 
 120 
 
THE FUNGI. 121 
 
 in other particulars, seeming to be more nearly related to 
 these than to any other plants. 
 
 Botanists are divided in opinion as to whether the Fungi 
 have developed independently from a common origin or 
 are a heterogeneous group that has resulted from the de- 
 generation of different chlorophyl-bearing plants. The 
 weight of authority seems to be in favor of the latter view. 
 So strong is the resemblance in the life history of many of 
 the Fungi to algal forms, that both are placed in the same 
 classes in some schemes of classification, the Fungi being 
 treated simply as degenerate forms of Algse. 
 
 Vegetative reproduction occurs in several different 
 ways, which will be considered in connection with different 
 plants. Sexual reproduction is known in some families, 
 but in the majority of cases the propagation is by asexual 
 processes. Reproduction by parthenogenesis occurs in 
 some forms. These plants are remarkable for polymor- 
 phism, i.e., they occur in different forms at different stages 
 of their existence. Polymorphism greatly complicates the 
 difficulties of the study of the Fungi, especially in matters 
 of classification. Our knowledge of these plants is still 
 very incomplete, owing to the difficulties in the way of 
 their study and the immense number of forms. There 
 are six classes : 
 
 CLASS I. THE CHYTRIDIE^E. 
 
 CLASS II. THE SMUT FUNGI (Ustilaginece) . 
 
 CLASS III. THE MOLDS AND MILDEWS (Phy corny cetes). 
 
 CLASS IV. THE SAC FUNGI (Ascomycetes). 
 
 CLASS V. THE RUSTS (JEcidiomycetes or Uredinece). 
 
 CLASS VI. THE TOADSTOOLS AND THEIR ALLIES (Basi- 
 diomycetes) . 
 
 CLASS I. The Chytridieae. These are very simple 
 organisms. Alternation of generations from gametophyte 
 to sporophyte is known in some forms. Asexual repro- 
 
122 
 
 PRACTICAL BOTANY. 
 
 duction by zoospores or zoogonidia also occurs. The 
 plants of this class are found as parasites on algae ; some- 
 times also on Flowering Plants, and on animals and Fungi 
 which live in the water. Relationship can be traced 
 between members of this class and members of several of 
 the higher classes of Fungi. 
 
 References for Reading. GoebePs " Classification of Plants," p. 85; 
 Vines' " Text-Book of Botany," pp. 285, 286 ; Bennett and Murray's 
 " Cryptogamic Botany," pp. 344-347 ; Carpenter's " The Microscope," 
 p. 565. 
 
 CLASS IT. The Smut Fungi (Ustilaginece). The Smuts, 
 or Bunts, are parasites on various flowering plants. They 
 
 are especially common on the 
 grasses, causing diseases which 
 are sometimes very destruc- 
 tive to the cultivated grasses. 
 The attack of the smuts is in 
 most cases confined to some 
 particular part of the plant, 
 as the leaf, the stem, or the 
 flower, on which they form 
 spots that are brown or yel- 
 low during the early stages, 
 but become black as the spores 
 ripen. In some cases the 
 smut spreads through all the 
 different parts of the plant. 
 The course of development of these Fungi, so far as it 
 is known, is believed to be as follows : The black resting 
 spore germinates into a promyceliuvi, a minute plant of 
 few cells. The promycelium bears male and female spo- 
 ridia; spores from these unite and the zygospore thus 
 formed develops into a mycelium; this mycelium produces 
 another crop of the black resting spores. The promyce- 
 lium is the gametophyte; the mycelium is the sporophyte. 
 
 FIG. 64. Wheat bunt (Tilletia 
 caries) . (Kellerm au . ) 
 
66 
 
 FIG. 65. Smut spores of Tilletia caries, p, the promycelium ; a bears young 
 sporidia ; in b, the sporidia have connected by conjugating tubes to form 
 zygospores ; c shows a portion of the mycelium which has developed from 
 a zygospore, and which bears a gonidium at s', filled with the black spores. 
 (After Tulasne.) 
 
 FIG. 66. Resting spores germinating. A, of Tilletia caries; B, of Ustilago 
 receptaculorum. (Vines.) 
 
 FIG. 67. Oats smut (Ustilago carbo). (After Smith.) 
 FIG. 68. Part of smutted ear of Corn. (After Tulasne.) 
 123 
 
124 
 
 PRACTICAL BOTAN Y. 
 
 The Ustilago maydis, the smut that attacks Indian Corn, 
 will serve as an example of these plants. It attacks the 
 corn in different places the stem, leaf, tassel, and the 
 ear. The diseased portions of the corn grow to ah abnor- 
 mal size, and all the tissues within the epidermis gradually 
 give place to the developing spores. These spores form 
 
 FIG. H9. Smut spores germinating. (Kellerman.) 
 
 in such quantity that the epidermis is finally broken 
 through, and the black, smutlike spores are scattered to 
 the wind. 
 
 References for Reading. Goebel's " Classification of Plants," pp. 
 85-88 ; Cooke's " Introduction to the Study of the Fungi," pp. 251- 
 258; Vines' "Text-Book of Botany," pp. 308-310; Bennett and Mur- 
 ray's " Cryptogamic Botany," pp. 349-352. 
 
THE FUNGI. 125 
 
 CLASS III. The Molds and Mildews (Phy corny cetes). - 
 The most important plants of this class are the Black 
 Molds, the Mildews and Rusts, and the Water Molds. 
 
 The Black Molds {Mucorinece) . The Mucorinece are 
 among the commonest of the molds. They are found in 
 abundance on moist, decaying organic matter. They are 
 saprophytic in their nourishment. The plants grow from 
 rootlike filaments which interlace just above or just be- 
 neath the surface of the substance on which the mold 
 grows. This interlacing rhizoid is called a mycelium. 
 From it delicate stalks or hyphse rise tipped with en- 
 larged masses which are sporangia filled with spores. As 
 the spores ripen they become dark colored so that the 
 mold, which was in the earlier stages colorless or white, 
 turns black. 
 
 The reproduction is ordinarily asexual by the spores 
 already mentioned. These spores dry up and are carried 
 about in the air. They, retain their vitality indefinitely. 
 When they fall on decaying organic matter under suit- 
 able conditions of temperature and moisture, they develop 
 at once by cell multiplication into new plants. 
 
 The sexual process of reproduction is of much less fre- 
 quent occurrence than the asexual process. Two hyphse, 
 which must, of course, be of opposite sexes, send out pro- 
 jections to meet. These projections are then separated 
 from the hyphse that produce them by the growth of a 
 cellulose wall. The meeting ends of the projections break 
 away, and the contents of the two cells mingle in one. 
 The resulting zygospore becomes encysted in a wall 
 that is sometimes covered with curious protuberances. 
 According to Strasburger, it is easy to raise the zy go- 
 spores in moist chambers by sowing the asexual spores 
 on thick plum juice mixed with 10 to 20 per cent of 
 ethyl alcohol. Zygospores are also said to be formed in the 
 spring of the year on Mucor that grows on horse manure. 
 
FIG. 70. Mucor mucedo. A, a portion of the mycelium with hyphae, 1, 1, 
 rising from it bearing sporangia, 2, 2 ; B, a piece of a hypha, showing the 
 structure; C, a young sporangium, showing the formation of the partition 
 which cuts it off from the hypha ; D, a nearly ripe sporangium, filled with 
 spores, and showing the columella extending into it; E, a fully ripened 
 sporangium discharging its spores and mucilage ; F, a part of E more highly 
 magnified ; G, the columella with the collar attached ; H, spores beginning 
 to germinate ; I, the same developing into mycelia ; K^-K 5 , five stages in 
 conjugation, showing the progress from the beginning of the conjugation 
 in K l up to the complete zygospore in K 5 ; L, L, ferment cells that have 
 developed from submerged hyphae. (Parker.) 
 
 126 
 
THE FUNGI. 127 
 
 It is thought that the zygospore formed by some species 
 does not develop. In the case of other species, it is known 
 that, after a period of rest, the zygospore develops hyphse 
 which bear sporangia, but does not develop a mycelium. 
 The spores borne in these sporangia develop in the asexual 
 way into new plants. These new plants multiply in the 
 asexual way, and it is probable that it is only after a num- 
 ber of generations have been produced that the sexual 
 process is repeated to reinvigorate the plant. 
 
 A third process of reproduction sometimes occurs. By 
 this process asexual spores, chlamydospores, are formed 
 in starved filaments of the mycelium. 
 
 The black molds may be sought on decaying moist 
 bread, on preserved fruits, and, in general, on decaying 
 organic matter. 
 
 The molds that develop on and in the bodies of cer- 
 tain insects, especially on flies and caterpillars, are closely * 
 related to the black molds. The growth of these molds 
 constitutes a disease which kills the insect. The mold 
 continues to grow after its death. It is frequently seen 
 fastening its victim to the walls of a room or to a window 
 pane. , The disease is communicated from one insect to 
 another by the spores that the mold produces. The 
 spores are borne about in the air, and if one happens to 
 fall on a moist portion of an insect, the disease results. 
 It is said that in the West Indies it is not at all uncom- 
 mon to see insects related to our wasp flying about with 
 plants, as large as the insects themselves, growing from 
 some part of their bodies. 
 
 MUCOR. PRACTICAL STUDIES. 
 
 Keep a piece of wet bread in a moist chamber until a 
 moldy growth appears on its surface. Some of this 
 growth will almost certainly be Mucor stolonifer. A 
 
128 PRACTICAL BOTANY. 
 
 similar cultivation on fresh horse manure will produce 
 Mucor mucedo. Mucor can be distinguished from other 
 growths, in part by the greater size ; in part by the black 
 color of its spores ; and in part by the fact that in young 
 plants there are no septa except those which cut off 
 the spherical spore-bearing knobs, the sporangia, from 
 their hyphse. In older plants septa are sparingly formed, 
 but are far less numerous than in other growths likely to 
 be present. 
 
 This is the first plant thus far studied among the Fungi 
 which shows even a rudimentary differentiation into root 
 and shoot ; among the Algse a similar differentiation has 
 been noted in the case of the Characeae. The aerial shoots 
 do not show any differentiation into leaves, nor do they 
 in any way function as leaves. They do not contain 
 chlorophyl, and cannot assimilate carbon dioxide, even if 
 it makes its way into them by osmotic action. The root 
 hyphse, on the contrary, show in quite a marked degree 
 something that is similar to the root pressure which is 
 characteristic of the higher plants. They take in water 
 by osmotic action so vigorously that it is forced up into 
 the aerial branches with energy enough, in some cases, to 
 burst through the walls of the sporangia. 
 
 1. Tear off a very little of the growth and mount in 
 water. Examine the mycelium (the interlacing rhizoid 
 portions) and the hyphse (the erect aerial stalks) for 
 septa. Examine the sporangia which tip the hyphse. 
 The cell walls of the older sporangia are densely covered 
 with crystals of calcium oxalate, which dissolve the in- 
 stant they touch the water, setting the inclosed spores 
 free, together with the mucilage which surrounds them 
 in the sporangia. The young sporangia retain their 
 spherical shapes. 
 
 2. Notice an ovoidal projection of the hypha into the 
 sporangium. This is the columella. In some cases where 
 
TIIK FUNGI. 129 
 
 the spores have been completely set free, a ringlike pro- 
 jection around the base of the columella may be seen. 
 This is the collar. 
 
 3. Run iodine solution under the cover glass. The 
 protoplasmic cell contents are slightly stained, the cell 
 wall is not affected, no blue color of the starch reaction 
 is seen, but some spots of a brownish color show the pres- 
 ence of glycogen a substance closely related to starch. 
 
 4. Treat another mount of the hyphse with one per cent 
 osmic acid. Granules in the protoplasm turn brown, 
 showing the presence of oil. 
 
 5. Run Schultze's solution under the cover glass of a 
 fresh specimen and examine the cell wall. The cell wall 
 is stained violet. Is it composed of ordinary cellulose or 
 fungous cellulose ? 
 
 6. Make hanging-drop cultures of the spores. Cement 
 rings of gutta percha or metal to glass slips to serve as 
 culture chambers. Smear the tops of the rings with vase- 
 line. Now place drops of Pasteur's solution, or of the 
 rich juice made by stewing apricots in water and sugar, 
 on the centers of cover glasses. Sow spores of Mucor in 
 these drops. Invert the cover glasses carefully over the 
 rings and press them down into the vaseline, thus forming 
 air-tight, moist chambers. Set aside in warm places and 
 examine from day to day to watch the development of 
 the spores. Make drawings, showing the development at 
 successive stages. 
 
 7. Place a piece of bread bearing a healthy growth of 
 Mucor in a position where the light is equally strong on 
 all sides. Observe after a time that the aerial hyphse 
 grow straight upwards ; they are negatively geotropic. 
 Observe that the root hyphge groAV downwards ; they 
 are positively geotropic. 
 
 8. Place a healthy growth of Mucor in a position where 
 the light is much stronger on one side. After a time 
 
 CLARK'S BOX. 9 
 
130 
 
 PRACTICAL BOTANY. 
 
 notice that the aerial hyphse turn towards the light ; they 
 are positively heliotropic. 
 
 References for Reading. Goebel's "Classification of Plants," pp. 
 90-92 ; Vines' " Text-Book of Botany," pp. 287-289 ; Carpenter's 
 " The Microscope," pp. 569-571 ; Bennett and Murray's " Crypto- 
 gamic Botany," pp. 335-343 ; Strasburger and Hillhouse's " Practical 
 Botany," pp. 255, 256 f; Parker's "Practical Biology," pp. 158-168; 
 Bidgood's "Elementary Biology," pp. 72-79; Bower's "Practical 
 Botany," pp. 497-502 ; Huxley and Martin's " Practical Biology," pp. 
 420-429 ; Cooke's "Introduction to the Study of Fungi," pp. 226-229. 
 
 The Mildews and White Rusts (Peronosporece). These 
 are especially important members of the class on account 
 
 of their destructive ef- 
 fects on valuable food 
 plants. They may be 
 found on the Grape as 
 mildew, Peronospora viti- 
 cola. One species, Phy- 
 tophthora or Peronospora 
 infestans, causes a Potato 
 disease; another species, 
 Cystopus candidus, grows 
 on Lettuce, Radish, and 
 Shepherd's Purse ; an- 
 other on Spinach, Pero- 
 nospora effusa; another, 
 
 FIG. 71. Diseased Potato leaf. A Po- n . *i7v 
 
 tato leaf infected with downy mildew, Cystopm Ultl, grows On 
 
 Peronospora infestans. The figure Pigweed ill late autumn, 
 
 shows portions of the leaf covered rr^^ ^ j j/u 
 
 with a dense mass of the Fungus which The ra P ld spread ot these 
 
 when mature turns the leaf dark 
 brown or black. (After Marshall.) 
 
 diseases IS Caused by 
 ,, ,. . ,, 
 
 the dissemination of the 
 spores by the wind. The spores fall on the plants, and 
 develop, sending their rhizoids through the stomata or 
 the thin, moist epidermis of the leaves, developing hau- 
 storia a special form of mycelium growth in the 
 
FIG. 72. Section of Potato leaf, showiiig development of mildew, Perono- 
 spora infestans. The figure shows the mycelium, o, interlaced among the 
 cells of the potato leaf ; the stalk, or hypha, 6, passing through a stoma ; 
 and the gonidia, c, c, which bear the spores. (After Marshall.) 
 
 FIG. 73. Surface of Potato leaf greatly magnified, showing germinating 
 spore entering breathing pore at a, and going through epidermis at c. 
 Another spore that has not begun to germinate is seen at 6. (Ward.) 
 
 131 
 
132 PRACTICAL BOTANY. 
 
 cells of the plant on which they are parasitic. Some of 
 these plants live, under different conditions, either as para- 
 sites or saprophytes. Some grow in the dead bodies of 
 animals. An alternation of generations occurs, at least 
 in most species. The ordinary form of the plant is the 
 gametophyte. 
 
 Stalks rise from the mycelium of mildews through the 
 stomata, and develop at their ends gonidia filled with 
 spores. Late in the season a special kind of gonidium, 
 known as a perithecium, is developed which bears the 
 spores that continue the life of the plant through the 
 winter. The gonidia of the white rusts are developed in 
 chainlike rows just below the epidermis. The oogonia 
 and antheridia of the sexual reproduction are also pro- 
 duced beneath the epidermis in the intercellular spaces of 
 the host plant, on branches of the stalks or hyphse. 
 
 CYSTOPUS CANDID US. PRACTICAL STUDIES. 
 
 Obtain some Shepherd's Purse or some Purslane, and 
 some of the flowers of Radish, affected with Cystopus. 
 Preserve in alcohol. Alcoholic material may be used for 
 all the observations except Number 3. 
 
 1. Notice the sori or white spots formed by the Fungus 
 on the leaves. Find some that are beginning to form 
 under the epidermis. As the Fungus develops, the epi- 
 dermis gives way and the Cystopus is exposed to the air. 
 Shake a matured and dry specimen over a dark surface, 
 and some of the asexual spores will fall out. 
 
 2. With the forceps tear off some of the white growth 
 and mount in water. Examine with high power. Numer- 
 ous ovoid asexual spores of Cystopus will be found. If 
 the specimen was not too dry, some will be found still con- 
 nected in short chains. Do you find chlorophyl bodies? 
 Test for starch. Is it present ? 
 
THE FUNGI. 
 
 3. Place some fresh leaves, bearing Cystopus, in. a warm, 
 moist chamber over night. In the morning mount some of 
 the white growth in water. After an hour or so examine 
 for motile zoospores which have escaped from the spores. 
 After watching their motion for a time, run iodine solu- 
 tion under the cover glass and determine whether or not 
 the motion is produced by cilia. Draw. The zoospores 
 remain motile only a short time. They then grow by cell 
 division and produce new plants of Cystopus. 
 
 4. Under the cover of a preparation similar to that in 
 Number 2 run Schultze's solution. Is the cell wall com- 
 posed of ordinary or of fungous cellulose? 
 
 5. Macerate in caustic potash for some time small pieces 
 of the leaf bearing the Cystopus, taking care to put in as 
 little as possible of the healthy parts of the leaf. Then 
 tease out the Cystopus in a drop of water on a glass slip, 
 add a drop of Schultze's solution, cover and examine. 
 Find tangled masses of the mycelium which have been torn 
 out of their positions in the cells of the host plant. Do 
 you find septa? Draw a portion of the mycelium, show- 
 ing the hyphaB and the chains of asexual spores in position 
 on the hyphse. 
 
 6. Place a leaf bearing sori between two pieces of pith 
 and cut delicate transverse sections through the sori, 
 keeping the pith and razor wet with alcohol. Examine 
 some of the sections, applying Schultze's solution. If the 
 sorus was young, the gonidiophores (stalks bearing the 
 asexual spores) will be found just below the epidermis of 
 the host. If the sorus was old, the epidermis of the host 
 will have broken away and its edges will be turned out. 
 Look for haustoria, the minute transparent globular 
 suckers which the Cystopus sends into the cells of the 
 host to rob them of their contents. These will be most 
 easily found in the youngest sori. Draw several, showing 
 their attachment to the mycelium. If they cannot be 
 
134 PRACTICAL BOTANY. 
 
 found in the sori on the leaves, look for sori on the pedicels 
 of the youngest flowers of Radish ; section, and examine. 
 It is not always easy to obtain material for this and the 
 following observation. 
 
 7. Stain thin sections of the diseased flowers of Radish 
 with Schultze's solution and examine for the organs of the 
 sexual reproduction. The nearly spherical oogonia and 
 antheridia take a deep red stain. The antheridia are 
 smaller than the oogonia. Draw a typical pair. Notice 
 the ova in the oogonia. Find also in mature oogonia the 
 oospores which result from the fertilization of the ova. 
 These oospores are the resting spores. Protected by the 
 greatly thickened tissues of the flowers, they lie dormant 
 through the winter. In the spring they are set free by 
 the decaying of the flowers, are scattered about by the 
 wind, and falling on favorable plants produce new crops 
 of Cystopus. 
 
 It may in some cases be possible to see a fine tube con- 
 necting the antheridium with the oogonium. Were the 
 antheridium necessary in all cases for the fertilization of 
 the egg cell, the connecting tube would be seen in many 
 cases, but it is probably the fact that fertilization is in 
 most cases by parthenogenesis. 
 
 References for Reading. Goebel's " Classification of Plants," pp. 
 92-96 ; Vines' " Text-Book of Botany," pp. 291-293 ; Cooke's " Intro- 
 duction to the Study of Fungi," pp. 230-232 ; Bessey's " Essentials of 
 Botany," pp. 139-143; Bennett and Murray's "Cryptogamic Botany," 
 pp. 323-332 ; Arthur, Barnes, and Coulter's " Plant Dissection," pp. 
 43-51; Bower's "Practical Botany," pp. 491-496; Strasburger and 
 Hillhouse's " Practical Botany," pp. 256 f-258 ; Carpenter's " The 
 Microscope," pp. 567, 568; Sachs' " Physiology of Plants," pp. 370-390. 
 
 The Water Molds (Saprolegniece). These are sapro- 
 phytic or parasitic plants that grow on the bodies of fishes 
 in the water, and in the case of a few species in the living 
 tissues of animals. It is this plant that causes a disease 
 
THE FUNGI. 
 
 135 
 
 which is very destructive to salmon. These plants closely 
 resemble Vaucheria in the process of reproduction, both 
 sexual and asexual. The alternation of generations is 
 well marked. The plant AMya prolifera is a type. It 
 may be easily raised by placing dead flies in water. 1 
 
 Fio. 74. Water Mold, a, end of filament, showing the partition cutting 
 off the protoplasm near the end from the rest of the filament ; b, same, 
 with protoplasm divided into escaping zoospores; c, zoospores inside a 
 filament ; d, filament showing oogonium and antheridium ; e, filament after 
 fertilization of oogonium. Magnified. 
 
 After a few days, transparent or whitish branched fila- 
 ments grow from various parts of their bodies. In gen- 
 eral outline the tubular partitionless filaments resemble 
 1 Arrange Practical Studies of this plant. 
 
136 PRACTICAL BOTANY. 
 
 the branching filaments of Vaucheria. In the methods of 
 reproduction the resemblance is also striking. The asex- 
 ual reproduction is by the formation of zoospores or zoogo- 
 nidia, which develop in special cells that become cut off 
 from the rest of the filament by transverse partitions. 
 The zoospores are flagellated and swim about in the cell 
 in which they are formed before they are liberated by the 
 decay of the cell wall. They are then set free and swim 
 about in the water for a time. They finally develop into 
 new filaments of the plant. 
 
 The sexual reproduction is as follows : Globular oogonia 
 are developed at the extremities or at points along the 
 sides of the branches. The antheridia are borne on the 
 extremities of small branches that develop just below 
 the oogonia. (Fig. 74, d and e.) The antheridia pene- 
 trate the oogonia, but the actual transfer of antherozoids, 
 or of protoplasm in any form, into the oogonia has never 
 been observed. The egg cells are believed to be fertilized 
 parthenogenetically, i.e., without receiving the contents 
 of the male elements. The fertilized eggs are discharged 
 and grow into new plants. 
 
 Parasites that grow on pond scums, Desmids, Dia- 
 toms, and other fresh-water plants, are related to the 
 Saprolegriiese, as also are parasites that may be found 
 on the Plantain, the Mints, the Evening Primrose, and 
 some leguminous plants. 
 
 References for Reading. Vines' "Text-Book of Botany," pp. 293, 
 294 ; Goebel's " Classification of Plants," pp. 96-99 ; Cooke's " Intro- 
 duction to the Study of Fungi," pp. 233, 234 ; Bennett and Murray's 
 " Cryptogamic Botany," pp. 332-334 ; Bessey's " Essentials of Botany," 
 pp. 136-139 ; Carpenter's " The Microscope," p. 569. 
 
 CLASS IV. The Sac Fungi (Ascomycetes). The dis- 
 tinguishing feature of this class is the formation of spores 
 in sacs or asci. These sacs are club shaped or globular. 
 The class is a large one and includes many common plants, 
 
THE FUNGI. 
 
 137 
 
 FIG. 75. Grape Mildew, Uncinula ampelopsidis. b, a small piece of myce- 
 lium bearing liaustoria at d, d, and spores at e ; c, a spore germinating ; 
 a, a perithecium, i.e., a spore case that develops late in the season. (After 
 Scribner.) 
 
 which grow as parasites on living plants or as saprophytes 
 on decaying plants. Besides the characteristic reproduc- 
 
 FIG. 76. Apple Powdery Mildew, a, mycelium bearing hyphae, c, which in 
 turn bear chains of summer spores, 6 ; cl, perithecium or winter spore case. 
 Magnified. (After Burrill.) 
 
 tion by ascospores, many of these plants bear ordinary 
 spores in gonidiophores that are raised on stalks. There 
 
138 
 
 PRACTICAL BOTANY. 
 
 is a recognized alternation of generations, though in many 
 species the sexual forms have become suppressed through 
 degeneration. Besides the undoubted Ascomycetes there 
 are plants that are doubtfully placed here. Among the 
 more common plants of the class are the blights that 
 grow on the Lilac (Micro splicer a friesii), on Hops (Podo- 
 
 sphcera castagnei), on 
 the Cherry and Apple 
 ( Podosphoera tridac- 
 tyla), on the Willow 
 ( Uncinula adunca), on 
 Peas (Erysiphe martii), 
 on Grasses (Erysiphe 
 graminis), on Butter- 
 cups (Erysiphe commu- 
 m'), on Celery (Oer- 
 cospora apii). Other 
 members of the class 
 are the common molds 
 the herbarium mold 
 (Eurotium), the blue 
 mold ( Penicillium ). 
 The Truffles are inter- 
 esting members of the 
 class. They are na- 
 tives of Europe, in some 
 parts of which they are 
 cultivated J:QE. the market ; they occur to some extent in 
 America. The spore fruits are produced in the ground. 
 They are very large, being sometimes six inches in diam- 
 eter. These are the edible parts, and they are highly 
 prized as an article 'of food. One of the doubtful orders 
 includes ordinary yeast (Saccharomyces cerevisice) and 
 other related yeasts. Here also belong certain Lichen- 
 forming Fungi. 
 
 FIG. 77. A vertical section through an 
 apothecium of the Lichen, Anaptychia 
 ciliaris, showing the spores in various 
 stages of advancement in the asci, 1, 2, 3, 
 4 ; p, the paraphyses of the hymenium ; 
 y, the subhymenial layer ; m, the loose 
 fungal constituents. (Goebel.) 
 
THE FUNGI. 
 
 139 
 
 References for Reading. Goebel's " Classification of Plants," pp. 
 100-114; Vines' "Text-Book of Botany," pp. 298-303; Bennett and 
 Murray's " Cryptogamic Botany," pp. 353-381; Bower's "Practical 
 Botany," pp. 470-472 ; Strasburger and Hillhouse's " Practical 
 Botany," pp. 269-271 ; Cooke's "Introduction to the Study of Fungi," 
 pp. 164-172 ; Bessey's " Essentials of Botany," pp. 155-165 ; Carpen- 
 ter's " The Microscope," pp. 571-574. 
 
 The Lichens, often popularly mistaken for Mosses, 
 grow everywhere on stones, trees, fences, and the ground. 
 They are for the most part Sac Fungi ; a few belong with 
 the Toadstools. Until within recent years they were 
 thought to be independent plants, but they are now 
 known to be parasites of a very peculiar kind. The 
 plants upon which they grow belong to the lowest orders 
 of the green plants, such as Protococcus, Chroococcus, 
 Gloeocapsa, and Nostoc. The Fungi grow in such a way 
 that they entirely envelop the 
 host plant, which seems to gain 
 a decided advantage from the as- 
 sociation, so that it often grows 
 in places where it could not 
 possibly exist without the pro- 
 tection and moisture afforded 
 by the enveloping Fungus. Such 
 growth of plants in interde- 
 pendence upon one another is 
 known as symbiosis or commen- 
 salism. 
 
 The thallus of the Lichen 
 sometimes clings closely to the 
 supporting surface. Such Li- 
 chens are called crustaceous. 
 (Fig. 78.) Sometimes the thal- 
 lus is flat, but has curled or crisped edges. Such Lichens 
 are called foliaceous. (Fig. 79, B.) Sometimes the Lichens 
 
 FIG. 78. ^, Graphit 
 
 crustaceous Lichen ; B, a 
 small portion of the same 
 more highly magnified; C, 
 Pertusaria Wulfeni, also a 
 crustaceous Lichen. (Goebel.) 
 
140 
 
 PRACTICAL BOTANY. 
 
 are attached to the supporting surface by a very small 
 area and rise from it with branching treelike forms. 
 Such Lichens are called fruticose. (Fig. 79, A.) 
 
 The sexual reproduction is known to exist in Lichens, 
 at least in some species, but is as yet imperfectly 
 understood. 
 
 By the asexual method of reproduction, spores are 
 produced in sacs. (Figs. 77 and 81.) These sacs are 
 
 Fia. 79. A, Usnea barbata, a fruticose Lichen; B, Sticta pulmonacea, a 
 foliaceous Lichen ; a, a, a, in both figures, apothecia. (Goebel.) 
 
 sometimes wholly inclosed in the tissues of the Lichen ; 
 sometimes they are grouped in circular masses that show 
 conspicuously as disks on the surface of the thallus. 
 (These may be seen in Figs. 78, 79, and 82.) They 
 are to be studied by making sections through these disks. 
 Material for practical work may be kept in the dry 
 condition indefinitely ; upon being wet, the dried Lichen 
 resumes its active existence. 
 
THE FUNGI. 
 
 141 
 
 THE LICHENS. PRACTICAL STUDIES. 
 
 1. Observe Lichens in their natural locations on trees, 
 stones, fences, and the ground. Some, the crustaceous 
 Lichens, are so closely attached to the substratum that 
 they cannot be removed entire. Others, the foliaceous, 
 are attached in only a few places by rootlike processes 
 called rhizines (Fig. 80, r,r); 
 
 the edges of the crustaceous 
 Lichens are more or less 
 curled or crinkled. Still 
 others, the fruticose Lichens, 
 are attached in only one 
 place, and rise in branching 
 shrublike forms from their 
 substratum. 
 
 2. Find Lichens bearing 
 disk or cup-shaped spots. 
 These are the fructifications, 
 the apothecia. They will be 
 more minutely studied later. 
 At present find as many dif- 
 f erent kinds of Lichens bear- 
 ing apothecia as possible. 
 (See Figs. 78, 79, 82.) 
 
 FIG. 80. A transverse section 
 through a foliaceous Lichen, not 
 passing through an apothecium; 
 o, epidermal layer of the upper 
 side ; g, the gonidial layer ; m, the 
 loosely arranged algal layer ; r, r, 
 rhizines. (Goebel.) 
 
 3. Place pieces of any 
 foliaceous Lichen that is not 
 gelatinous between pieces of pith, and cut vertical sections 
 not passing through an apothecium. Mount in water. 
 The water causes the tissues to swell to such an extent 
 that it is not easy to make sections which will show all the 
 structures fully. A number of sections should therefore 
 be cut and the most favorable selected. 
 
 Beginning at the upper surface, observe that the tissues 
 have become differentiated to form a more or less colored 
 
PRACTICAL BOTANY. 
 
 outer layer or epidermis. Beneath the epidermis is a layer 
 of dense, colorless, fungal tissue. Below this is a layer 
 containing green cells of the algal constituents of the 
 Lichens. These green cells were formerly thought to be 
 the fructifications, and were called gonidia, which name is 
 
 still retained. Notice 
 that the hyphse of the 
 Fungi are in close con- 
 tact with the algal cells. 
 Passing below the algal 
 layer, the fungal tissue 
 becomes looser, and the 
 interlacing, branching, 
 colorless tubular cells of 
 
 FIG. 81. Section through the apothecmm 
 
 of Anaptychia ciliaris. m, the algal which it is Composed 
 
 portions; g, the gonidial portions; h, s h ow morp r l ear l v fheir 
 the hymenium; y, the subhymenial 
 
 layer. A small portion of this apothe- fungal nature. On the 
 
 cium may be seen more highly magni- l nwpr ;,] n f fh p QPP firm 
 
 fied in Fig. 77. (Goebel.) L W6r S1Cle Ol tne sectlon 
 
 the tissue passes again 
 
 into an epidermis. In favorable places the threadlike, 
 projecting rhizines may be seen. Repeat these observa- 
 tions on sections cut from a piece of Lichen that has been 
 kept in alcohol. Keep the specimen wet with alcohol 
 while cutting the sections, and mount the sections in 
 alcohol. (Compare Fig. 80.) 
 
 4. Cut transverse sections of the stem portion of the 
 fruticose Lichen Usnea barbata. (Fig. 79, A.) This Lichen 
 grows in abundance on old trees. It may be recognized by 
 its decidedly shrublike form, its round stem, its conspicuous 
 apothecia, which are flattened expansions of the thallus, 
 and its general bristling, bearded appearance. Mount the 
 sections in water. Observe how closely the cross section 
 of the stem of this Lichen simulates the stems of the 
 higher plants. On the outside the fungal tissue is differ- 
 entiated to resemble an epidermis ; then comes a layer of 
 
THE FUNGI. 143 
 
 dense fungal tissue which corresponds to a cortex ; inside 
 this is the green, gonidial layer, extending completely 
 around the stem ; inside the gonidial layer the fungal tis- 
 sue becomes looser ; in the center of the stem the fungal 
 tissue again becomes dense and of a more or less reddish 
 color. Repeat the observations on sections of alcoholic 
 material. 
 
 Remembering that all green, chlorophyl-bearing plants 
 require the sunlight, is the position of the Protococcuslike 
 algal constituents, as observed in the foliaceous and fruti- 
 cose Lichens in this and the preceding section, favorable 
 for their healthy development ? Remembering that these 
 Algae require moisture for their growth, is their envelop- 
 ment in the tissues of the Fungus favorable for their 
 development ? 
 
 5. Treat sections, not passing through apothecia, of 
 foliaceous and fruticose Lichens with iodine solution. Do 
 you find any indications of the presence of starch in the 
 fungal portions ? In the algal portions ? 
 
 6. In the Lichens thus far studied the algal constituents 
 have occupied a definite position separated from the fun- 
 gal constituents. Such Lichens are called 
 heteromerous. In certain gelatinous Li- 
 chens the algal constituents are scattered 
 
 without definite arrangement throughout 
 the thallus. Such Lichens are called homoi- 
 omerous. Make and examine sections of 
 such Lichens, which may be found in moist 
 
 T , i T -i i FIG. 82. Collema 
 
 locations on the ground and on rocks. puiposum, age- 
 (See Fig. 83.) Treat with iodine and latinous Lichen, 
 with Schultze's solution. 
 
 7. Make vertical sections through the apothecia of 
 Usnea barbata. Sections cut in paraffin from material 
 fixed in picric acid or corrosive sublimate, stained in 
 hsematoxylin or fuchsin, and mounted permanently in 
 
144 PRACTICAL BOTANY. 
 
 balsam or glycerine, are best for this observation. 1 Sec- 
 tions cut from fresh material and mounted in water or 
 glycerine will do. On the upper portion of the apothe- 
 cium, just below the epidermis, find ovoidal cells, the 
 
 asci, arranged perpen- 
 dicularly to the surface, 
 large end outward ; each 
 ascus, or sac, contains a 
 number of spores. Be- 
 tween the asci are long 
 narrow cells, also ar- 
 ranged perpendicularly 
 
 FIG. 83. -A vertical section through the to the surface; these are 
 gelatinous Lichen, Leptogium scotinum, 
 howing the algal constituents scat- paraphyses. The asci 
 
 and Paraphyses together 
 make up the hymenium. 
 (Compare Figs. 77 and 81.) Just below the hymenium 
 is the subhymenial layer, composed of dense, interlacing 
 fungal elements. Below this is the layer bearing the 
 algal constituents, which extend entirely around the sec- 
 tion. Inside the algal layer the fungal constituent be- 
 comes looser for a space, but in the central portions again 
 becomes dense. 
 
 Treat a section passing through the apothecium, made 
 from fresh material and mounted in water, with very 
 dilute iodine solution. The tissues of the hymenium 
 take on a blue color the starch reaction. Treatment 
 with Schultze's solution gives a similar result. The cell 
 walls of the hymenial tissues are composed of modified 
 cellulose, known as starch cellulose. Do iodine solution 
 and Schultze's solution give the blue color in other 
 portions of the fungal constituents ? In the algal con- 
 
 1 For the processes used in the preparation of vegetable specimens for 
 sectioning and mounting consult the author's "Practical Methods in 
 Microscopy," Chap. VII. 
 
THE FUNGI. 145 
 
 stituents ? The production of the spores is a result of a 
 conjugation, the study of which is too difficult for begin- 
 ners. Male gametes, spermatia, conjugate with female 
 gametes, trichogynes, inside the tissues of the hyphre. 
 The resulting apothecia emerge to the surface, where the 
 spores are exposed directly to the open air in gymno- 
 carpous Lichens, or are ejected through minute orifices in 
 the angiocarpous Lichens when the dried apothecium is 
 wet. 
 
 The spores germinate into hyphse, but this development 
 soon ceases and the hyphse die, unless they come in con- 
 tact with cells of the Algae with which they are associated 
 in forming the Lichen. When the hyphae and the Algse 
 come together, the development of each goes on vigor- 
 ously. The Algse, protected and furnished moisture by 
 the Fungus, take in carbon dioxide from the air and 
 mineral elements from the moisture. The rhizines of the 
 Fungus, in the case of many foliaceous Lichens, take up 
 mineral matters from the substratum, and even decom- 
 pose the substance of rocks and convey to the Algse the 
 inorganic materials necessary for the formation of proto- 
 plasm. As the protoplasm increases, the cells enlarge 
 and multiply by cell division. At the same time the 
 parasitic Fungus draws abundant sustenance from the 
 well-nourished cells of the Algae. 
 
 8. Besides the reproduction by spores, there is also a 
 vegetative reproduction by means of soredia. Select a 
 specimen of Usnea barbata that bears few or no apothecia, 
 and that appears powdery at least in places. Material 
 secured as soon as it has dried after a rain is best. Brush 
 some of the powder into a drop of water on a slide, and 
 examine under high power. Single algal cells and groups 
 of algal cells associated with fungal hyphse will be seen. 
 These are the soredia in their elementary stages. More 
 advanced stages will also be found. In these the hyphse 
 CLARK'S BOX. 10 
 
146 
 
 PRACTICAL BOTANY. 
 
 have grown towards each other on what was the outer 
 end of the soredium, as it grew 011 the parent Lichen, 
 forming an arch over the algal portions. The soredia 
 separate from the Lichens as they dry after rain, and are 
 then blown about by the wind. This mode of distribution 
 of the soredia and spores explains the abundance and wide 
 distribution of Lichen growths. (See Fig. 84). 
 
 FIG. 84. A, B, C, soredia of Usnea barbata in their earliest stages; D, E, 
 the same developing arched growths of the fungal constituent; a, b, c, 
 soredia of Physcia parietina in different stages of development. (From 
 Goebel, after Scliwendener.) 
 
 The arching growth of the hyphae over the Algae at 
 the outer end of the soredium also illustrates the typical 
 method of growth in much the largest number of heter- 
 omerous Lichens. The Fungus grows in advance, and 
 leads the way for the Algae. In a few heteromerous 
 Lichens the Algae grow in advance of the Fungi. In the 
 homoiomerous Lichens it has not yet been determined 
 whether the Fungus or Alga grows in advance. 
 
 References for Reading. Goebel's "Outlines of Classification," 
 pp. 114-126; Sachs' "Physiology of Plants," pp. 391, 514; Vines' 
 " Text-Book of Botany," pp. 319-320 ; Bennett and Murray's " Crypto- 
 gamic Botany," pp. 318-322 ; Bower's " Practical Botany," pp. 473- 
 480 ; Bessey's " Essentials of Botany," pp. 165-169 ; Strasburger and 
 Hillhouse's "Practical Botany," pp. 202-270; Carpenter's "The 
 Microscope," pp. 576-579 ; Geddes' " Chapters in Modern Botany," 
 pp. 114-119. 
 
THE FUNGI. 
 
 147 
 
 The Black Fungi (Pyrenomycetes) are important plants 
 of this class. Familiar examples of these are the black 
 knots common on Cherry and Plum trees. These plants 
 produce filaments which lie dormant under the bark until 
 the spring of the following year, when they develop rapidly, 
 producing a disease of the branch on which they grow by 
 causing an abnormal de- 
 velopment of the bark. 
 The gonidia formed by 
 the asexual process may 
 be studied on the surface 
 edge of thin sections of 
 the knot made in the late 
 spring ; the ascospores of 
 the sexual process may be 
 studied in thin sections 
 cut in the winter. The 
 spores may then be seen 
 in their sacs, and by the 
 
 FIG. 85. Claviceps purpurea, the Fungus 
 that produces ergot on Rye. A, a scle- 
 rotium or ergot that forms in the heads 
 of Rye, bearing seven stromata or fruc- 
 tifying heads; B, one of these heads 
 seen in section, showing the peri- 
 thecia, cp, which bear the asci; C, 
 a peritheciura containing asci more 
 highly magnified ; D, a single ascus 
 discharging its spores, sp. (From 
 Sachs, after Tulasne.) 
 
 sides of the sacs slender 
 filaments, the so - called 
 paraphyses. 1 
 
 There are many species 
 of Black Fungi. The 
 black spots that develop 
 on the leaves and bark of 
 
 different kinds of trees, 
 
 and ergot, a parasite on heads of rye and other grains, are 
 
 among them. 
 
 References for Reading. Vines' " Text-Book of Botany," pp. 301, 
 302; Bower's "Practical Botany," pp. 481-483; Cooke's "Introduc- 
 tion to the Study of Fungi," pp. 197-220; Bessey's "Essentials of 
 Botany," pp. 163-165. 
 
 1 Have on hand material collected at the different seasons, and pre- 
 served in alcohol or formalin. Arrange Practical Studies. 
 
148 PRACTICAL BOTANY. 
 
 The Saccharomyces, or Yeast Plants, are by some authori- 
 ties classed with the Bacteria. Their proper place in the 
 scheme of classification has not been determined. The 
 formation of ascospores under certain conditions of ex- 
 istence, and their resemblance in other respects to the 
 Ascomycetes, are strong reasons for placing them in this 
 class. 
 
 The yeast cell is ovoidal in shape. It consists of a 
 very delicate transparent wall of cellulose, inclosing proto- 
 plasm. More or less distinct, noncontractile vacuoles 
 may be seen. The vacuoles are simply spaces in the 
 interior of the cell not filled by the protoplasm. They 
 are, of course, filled with fluid. In some cells highly 
 refractive particles of fat and other granules, which are 
 the result of the nutritive processes of metabolism, are 
 found. The nucleus can be seen only after the use of 
 special staining processes which have been discovered 
 recently. 
 
 YEAST. PRACTICAL STUDIES. 
 
 Dissolve a yeast cake in water to which some sugar has 
 been added, or better in Pasteur's solution. After it has 
 been growing for some hours, place a drop of the fluid on 
 a glass slip and cover lightly with a cover glass. Examine 
 with high power. 
 
 1. Observe the prevailing ovoidal shape of the highly 
 transparent cells, being careful not to confound starch 
 granules that may be present with the yeast cells. If the 
 yeast is in an actively growing condition, the character- 
 istic mode of reproduction by budding will be seen. Bud- 
 ding is a modification of cell division in which one of the 
 newly formed parts is smaller than the other. The small 
 bud rapidly grows to the full size of the mother cell and 
 separates from it. The plant is, therefore, unicellular, 
 though retardation in the separation of the daughter cells, 
 
THE FUNGI. 149 
 
 due to the fact that the outer coating of the cell wall is 
 mucilaginous, frequently gives rise to chains or groups of 
 cells. Draw a single cell and groups of cells showing 
 buds. 
 
 2. Sow thin layers of yeast that is in the active bud- 
 ding condition on slabs of plaster of Paris or on freshly 
 cut surfaces of potato or turnip. The surface portions of 
 a cultivation of yeast obtained from a brewery are best 
 for this observation. Keep under bell jars, adding dis- 
 tilled water to the containing dish from time to time to 
 prevent the yeast from drying up. It is best to prepare 
 a number of these cultivations, as bacterial and fungoid 
 growths are likely to interfere. Examine mounts of the 
 yeast from the surface daily, after about a week, until 
 the contents of some of the cells are seen to have under- 
 gone division into two or four parts. The yeast cells are 
 starved, the vacuoles become larger and more numerous, 
 and, as a last effort to preserve life, the protoplasm divides 
 into what are virtually resting spores. These divided 
 cell contents indicate another method of reproduction. 
 They are known as ascospores or sac spores. They are 
 called sac spores because they are contained within the 
 wall of the mother cell as in a sac. Draw a typical cell. 
 
 3. Make a mount of actively growing yeast. Observe 
 the vacuoles clear spaces empty of protoplasm in the 
 central part of many of the cells. Between the vacuoles 
 and the surfaces of the cells observe the protoplasm, 
 which is quite clear in many of the cells ; in others, it 
 presents a granular appearance, due to the presence of 
 minute particles of oil and granules of proteinaceous 
 matter. 
 
 4. Study the cell wall. Press firmly on the cover 
 glass, and thus burst some of the cells. Observe the 
 colorless cell walls left empty of their contents. Run a 
 drop of magenta under the cover glass. The cell wall is 
 
150 PRACTICAL BOTANY. 
 
 not stained by this dye, but the cell contents take a pinkish 
 tinge. 
 
 Prepare another mount of the yeast, burst some of the 
 cells, and run iodine solution under the cover glass. The 
 cell wall is rendered more distinct, the protoplasm is 
 slightly colored, but none of the particles are stained 
 blue. Starch is therefore not present, consequently 
 chlorophyl is absent. These reactions are all more dis- 
 tinct, if, instead of using a fresh preparation, a thin layer 
 of the yeast is allowed to dry on the cover glass. A drop 
 of water is then placed on it, the cover glass is put in 
 position on a glass slip, and the iodine is applied. 
 
 Make another dry preparation on a cover glass, treat 
 with 70 per cent sulphuric acid for a few minutes, wash 
 out the acid with water, stain with dilute iodine solution, 
 and mount. The cell wall will be beautifully distinct in 
 some of the cells because of the shrinking of the proto- 
 plasm. 
 
 The cell contents may also be made to shrink by mount- 
 ing some fresh yeast and running a drop of a ten per cent 
 solution of common salt in water under the cover glass. 
 The shrinking of the cell contents is due to the fact that 
 the solution used passes freely through the cell wall itself, 
 but does not pass through the thin layer of the protoplasm 
 that lines the cell. This treatment is called plasmolyzing 
 the cell. 
 
 5. Prepare a dry layer of yeast on a slide and stain it 
 with Schultze's solution. This treatment stains the cell 
 walls of higher plants blue or violet, but gives a yellowish- 
 brown color to the cell walls of the Fungi. The material 
 of the cell wall is in this case fungous cellulose. That 
 fungous cellulose is closely related to ordinary cellulose is 
 proved by the fact that, after it has been treated with 
 dilute caustic potash for a long time, it gives the usual 
 blue or violet reaction with Schultze's solution. 
 
THE FUNGI. 151 
 
 6. Examine for the nucleus. Prepare a dry layer of 
 yeast on a cover glass ; fix the cell contents by allowing 
 the cover glass to remain in a strong solution of picric 
 acid for twenty-four hours. Wash thoroughly in water 
 to remove the picric acid, and stain in ammonia hoematoxy- 
 lin, which may be prepared by shaking some of the hyema- 
 toxylin crystals in distilled water to which a minute drop 
 of aqua ammonia has been added. Allow this stain to 
 act for several hours, but do not let it dry on the cover 
 glass. Wash thoroughly in water and mount. The 
 nucleus will now be seen in the center of the cells as a 
 small round mass more deeply stained than the rest of 
 the cell. 
 
 7. Prepare two test tubes containing actively growing 
 yeast. Wrap one in opaque paper. Stand the two tubes 
 in the bright light of a window. Prepare two other 
 tubes in the same way and stand in the diffused light of 
 the back part of the room. Does the presence or absence 
 of light affect the growth of the yeast ? 
 
 8. Grow yeast in Pasteur's solution in a flask, connect- 
 ing the flask by means of a delivery tube with a beaker of 
 clear lime water. After a time the lime water becomes 
 cloudy because of the formation of carbonate of lime 
 occasioned by the union of carbon dioxide, given off by 
 the growing yeast, with the lime water (calcium hydrox- 
 ide'). Distil what remains in the flask until about one 
 fifth of it passes over. Mix this distillate with potassium 
 carbonate and distil again. Observe a peculiar streaki- 
 ness on the neck of the retort ; this is characteristic of 
 alcohol. This distillate may further be proved to be 
 alcohol by its odor, by the fact that it will burn, and by 
 the green color and fruity odor produced when a little of 
 it is boiled after the addition of a few drops of a solution 
 of potassium bichromate and of sulphuric acid. A sub- 
 stance which has the power to effect decomposition as the 
 
152 PRACTICAL BOTANY. 
 
 yeast has decomposed the Pasteur's solution is called an 
 organized ferment. 
 
 References for Reading. Bidgood's " Elementary Biology," pp. 
 27-44; Parker's "Elementary Biology," pp. 71-81; Huxley and 
 Martin's "Practical Biology," pp. 377-388; Dodge's "Practical 
 Biology," pp. 28-39; Carpenter's "The Microscope," pp. 574, 575. 
 
 PENICILLIUM. PRACTICAL STUDIES. 
 
 Penicillium glaucum is one of the most common molds. 
 It is found on a large variety of substances that are 
 exposed to the air as a blue or green mold. It may be 
 raised for study by sowing its spores on Pasteur's solution 
 or on a decoction of vegetable matter, such as was used in 
 studying Bacteria. In fact, either of these solutions, left 
 exposed to the air, will generally bear the mold after a 
 few days. It first appears as minute tufts of cottonlike 
 filaments. These tufts enlarge in diameter and grow 
 thicker in the center. The inner portions gradually 
 change to blue, and finally to sage green, so that a well- 
 developed spot has a green center, surrounded by a ring 
 of blue and a second peripheral ring of white. 
 
 Penicillium glaucum resembles Eurotium somewhat in 
 its structure, but is readily distinguished from it by its 
 smaller size, by the color, and by the fanlike arrangement 
 of the spores in the heads. The formation of spore fruits 
 is known to occur, but their study is difficult for be- 
 ginners. 
 
 1. Cultivate some Penicillium on Pasteur's solution or 
 hay decoction. Carefully transfer one of the smallest 
 spots to a glass slip, keeping it right side up. Do not use 
 a cover glass. Examine with the lowest power. Notice 
 the mycelium, composed of interlacing filaments ; the 
 aerial hyphse rising erect into the air ; and the submerged 
 hyphse descending into the nutrient solution. 
 
THE FUNGI. 
 
 153 
 
 FIG. 86. 1, Mucor mucedo ; 2, longitudinal section of sporangium of same ; 
 3, fruit formation in same (see p. 125) ; 4, Asperyillus niger ; 5, longitudi- 
 nal section of a sporangium of same (related to Eurotium, see p. 155) ; 
 6, fructification of Penicillium crustaceum (after Brefeld) ; 7, fruit forma- 
 tion of Asperyillus (after Eidam) ; 8, Penicillium crustaceum ; 9, sporan- 
 gium of same (Kerner and Oliver). 
 
 2. With the forceps tear away some of the white fila- 
 ments of the outer ring. Mount them in 30 per cent 
 alcohol and examine under high power. What is the 
 shape of the distal end? Do these white filaments bear 
 gonidia? Are there septa across the filaments? Treat 
 with Schultze's solution. Are the cell walls composed of 
 ordinary or of fungous cellulose? 
 
154 
 
 PRACTICAL BOTANY. 
 
 3. Mount some of the filaments taken from the blue 
 ring in 30 per cent alcohol. Compare the distal ends of 
 these with those from the white ring. Do these bear 
 gonidia? Make another mount from the central green 
 portion. State how the distal ends of these compare with 
 the distal ends of filaments from the blue and white rings. 
 Compare the septa in the three mounts. Is Penicillium a 
 unicellular or multicellular plant? 
 
 4. Examine the gonidia. Show by a drawing the ar- 
 rangement of the spores. To the naked eye the spores in 
 
 mass appear blue or green. Can 
 you distinguish either of these 
 colors under the microscope? 
 The color is not due to chloro- 
 phyl. No chrornatophores can 
 be distinguished. Mount some 
 spores in alcohol, stain with 
 hyematoxylm, and try to make 
 out a nucleus. Treat another 
 mount of the spores with 
 Schultze's solution, and describe 
 the effects on the cell wall, nu- 
 
 ' 
 
 cleus, and cell contents. Treat 
 Bother mount with caustic pot- 
 ash and describe the effects. 
 
 5. Make hanging drop cultures of the spores. Set 
 aside in warm places and examine from day to day to 
 watch the development of the spores. Make drawings, 
 showing the development of successive stages. 
 
 6. Mount a little of the mycelium in 30 per cent alco- 
 hol, tearing it apart with needles. Notice the granu- 
 lar protoplasm. Do you find vacuoles ? Treat with 
 Schultze's solution. Of what kind of cellulose is the cell 
 wall composed? Mount some more of the mycelium in 
 alcohol, stain with haematoxylin, and make out the nuclei.. 
 
 FIG. 87. Pemcillium (jlaucum. 
 
 m, a portion of the mycelium ; 
 
THE FUNGI. 155 
 
 Show by a figure the manner in which the mycelium 
 branches. Are the branches of uniform diameter? If 
 not, state what differences you notice ; examine the ends 
 of the hyphie particularly. Treat another mount with 
 one per cent solution of osmic acid. A brown coloration 
 shows the presence of oil. This oil is one of the products 
 of the destructive metabolism of the protoplasm. 
 
 References for Reading. Parker's " Elementary Biology," pp. 184- 
 191; Bidgood's "Elementary Biology," pp. 80-84; Dodge's "Practical 
 Biology," pp. 297-300; Huxley and Martin's "Practical Biology," 
 pp. 415-426; Strasburger and Hillhouse's "Practical Botany," pp. 
 259-261. 
 
 EUROTIUM. PRACTICAL STUDIES. 
 
 Eurotium first appears as a white, cottonlike growth; 
 later yellow spots develop. It grows so readily on poorly 
 dried plant specimens that it receives the name Herbarium 
 Mold. It is also found on old leather, boot blacking, and 
 various other substances. 
 
 1. Mount a little Eurotium in water and examine the 
 mycelium under high power. Notice the septa. Draw a 
 typical case of branching. Run Schultze's solution under 
 the cover glass. Is the cell wall composed of normal or 
 of fungous cellulose? 
 
 2. Study the asexual reproduction. Are the gonidio- 
 phores branched or unbranched? Are they divided by 
 septa? Describe the manner in which the gonidia are 
 borne. Draw a gonidiophore to which a considerable 
 number of gonidia are still attached. 
 
 Make hanging drop cultures of the spores. Make draw- 
 ings on at least four different days, showing the progress 
 of the growth. 
 
 3. Study the sexual reproduction. Material for this 
 study is to be obtained from Eurotium that has been grow- 
 ing for some time. It may be recognized as suitable by 
 
156 
 
 PRACTICAL BOTANY. 
 
 the yellow color distinctly visible to the naked eye. Draw 
 a typical spore fruit. By pressure on the cover glass burst 
 some of the spore fruits and study the ascospores. Eight 
 
 ascospores are 
 borne in each 
 sac. Find as 
 many as possible 
 of the stages 
 in the develop- 
 ment of the spore 
 fruit. The be- 
 ginning of the 
 development is 
 by the out- 
 growth of a 
 spirally coiled 
 branch which 
 becomes the as- 
 cogonium. From 
 just beneath this 
 another branch, 
 the pollinodium, 
 rises, extending 
 to the top of 
 the ascogonium. 
 
 FIG. 88. Eurotium repens. A, a portion of the 
 mycelium bearing at st a gonidiophore, and at as a 
 young ascogonium ; B and C show the ascogonium 
 more advanced and enveloped in the pollinodium 
 p ; ZHs a fully matured ascogonium ; E and F are 
 sections through a young ascogonium ; G is one of 
 the asci or sacs that are borne in the ascogonium, 
 and H is one of the ascospores which are borne in 
 the ascus. (After Goebel.) See Fig. 86, 4 and 5. 
 
 It is supposed, 
 though this fact has not been proved, that the pollinodium 
 fertilizes the ascogonium. The ascogonium becomes en- 
 veloped in other branches which start from below its base 
 and tightly inclose it. The mature ascogonium bears 
 several sacs, each containing eight ascospores. 
 
 References for Reading. Bennett and Murray's "Cryptogamic 
 Botany," pp. 364-366 ; Huxley and Martin's "Practical Biology," pp. 
 419-427; Bower's "Practical Botany," pp. 484-490; Goebel's "Classi- 
 fication of Plants," pp. 105-107. 
 
THE FUNGI. 
 
 157 
 
 CLASS V. The Rusts (JEcidiomycetes or Uredinece). 
 The Rusts are parasites which infest the tissues of higher 
 land plants. They sometimes grow in the intercellular 
 spaces, and perhaps do no injury to their host. In other 
 cases they grow in the cellular tissues, often causing great 
 deformity and injury. (See Fig. 89.) The spores are 
 produced beneath the epi- 
 dermis of the host. They 
 are somewhat of the color 
 of iron rust, and so give 
 the common name to the 
 plant. Many species of 
 Rusts produce different 
 kinds of spores, but not 
 on the same plant. There 
 is a succession in their 
 development which re- 
 quires plants of different 
 kinds. A familiar exam- 
 ple of this is the Rust 
 that causes disease in Wheat. It is known as Puccinia 
 graminis. It has different kinds of spores. One kind 
 grows on the Wheat ; the other kind on Barberry bushes. 
 In the spring cuplike yellow clusters develop on the Bar- 
 berry leaves, producing spores called cecidiospores. These 
 spores are carried by the wind to Wheat fields, where 
 they grow and produce an entirely different kind of spore, 
 called uredospores. These new spores are carried to other 
 Wheat plants and develop. This continues as long as 
 the conditions are favorable. Late in autumn spores 
 with thick coats are produced, called teleutospores. These 
 develop in the spring on Barberry leaves into cuplike 
 clusters which bear the recidiospores. 1 
 
 1 Have on hand material collected from the different sources mentioned 
 and at the different seasons, and arrange Practical Studies. 
 
 FIG. 89. Section of Blackberry leaf, 
 showing development of Orange rust 
 spores. (After Clinton.) 
 
158 
 
 PRACTICAL BOTANY. 
 
 Another species of Rust, Puccinia rubigo-vera, affects 
 Wheat in the United States. This has no connection 
 
 FIG. 90. Clover Rust, c, cluster cups and aecidiospores ; d, uredospores; 
 /, uredo pustule on Clover leaf ; e, teleutospores ; g, cross section of Clover 
 stem, showing mycelium between cells ; also two teleutospores and one 
 uredospore. (After Pammel.) 
 
 with the Barberry, but its different stages are passed on 
 the Wheat and on plants of the Borage family. 
 
 The abnormal growth on the twigs of Cedar, known 
 as cedar apples, affords opportunity for the study of an- 
 
THE FUNGI. 
 
 159 
 
 other interesting Rust. These 
 cedar apples, if examined in 
 autumn or winter, are seen 
 to be covered with elevations 
 under the bark. They are 
 now in good condition for 
 study. Thin sections show 
 the spores in their sacs. The 
 bark over the elevations breaks 
 away in the spring and the 
 rust-colored spores appear on 
 the surface. These spores are 
 the teleutospores. They will 
 not grow on the Cedar, but 
 if, borne by the wind, they 
 fall on the leaves of the Apple 
 or Hawthorn, they grow and 
 
 a 
 
 FIG. 91. Cedar apples (Gymno- 
 sporangium davipes) . (Farlow.) 
 
 produce another kind of 
 spore the kind that 
 flourishes on Cedar. 
 
 The shape of the te- 
 leutospores determines 
 the classification of the 
 Rusts ; in all other 
 stages the different 
 kinds of Rusts resem- 
 ble one another so 
 much that they can- 
 not be distinguished. 
 
 No sexual reproduc- 
 tion is known, though 
 it is supposed that it 
 does exist. 
 
 FIG. 92. Corn Rust, Piiccinia maidis. a, 
 section of leaf, showing teleutospores; 6, 
 uredospores ; c, teleutospores. (Clinton.) 
 
 References for Reading. 
 Goebel's " Classification 
 of Plants," pp. 126-131; 
 
160 
 
 PRACTICAL BOTANY. 
 
 Carpenter's " The Microscope," pp. 565, 566 ; Vines' " Text-Book of 
 Botany," pp. 303-308 ; Bennett and Murray's " Cryptogamic Botany," 
 pp. 383-386; Cooke's "Introduction to the Study of Fungi," pp. 
 242-250. 
 
 CLASS VI. The Toadstools and their Allies (Basidiomy- 
 cetes~). This is a large class and contains a great variety 
 of forms, including some of the largest and handsomest of 
 the Fungi. They are for the most part saprophytes ; a 
 
 few are parasites. The 
 portion of the plant that 
 appears above the ground 
 or other substratum on 
 which it grows is the fruc- 
 tification. The plant itself 
 consists of delicate white 
 threads, the mycelium, 
 which ramify through the 
 substratum. Popularly the 
 principal members of this 
 class are divided into 
 Toadstools and Mushrooms. 
 Under the latter name are 
 included those forms that 
 may be used as food, and more particularly the species 
 that is largely cultivated for food, the Agaricus campestris. 
 From the botanical standpoint, there is no such classifica- 
 tion. The cultivated forms are propagated by placing 
 masses of humus containing the mycelium, which the 
 gardener calls spawn, in beds of prepared humus. The 
 mycelium spreads and bears repeated crops of Mushrooms. 
 The fructification of Toadstools is at first a more or less 
 egg-shaped body, the button, which is some days in forming 
 under the substratum. Then, if conditions are favorable, 
 it shoots up very quickly into the fully formed Toadstool. 
 A large number of Toadstools are edible, and many of 
 
 FIG. 93. A typical gill-bearing 
 Toadstool. (Weed.) 
 
THE FUNGI. 161 
 
 them are said to be most delicious and nutritious articles 
 of food. Directions are given in the books for dis- 
 tinguishing the edible forms from those that are not 
 edible. As a matter of fact, however, there are deadly 
 poisonous forms which so closely resemble nearly all the 
 edible forms that even the expert acknowledges the im- 
 possibility of describing so that one unfamiliar with them 
 may be at all sure of distinguishing the edible from the 
 poisonous. The only safe rule for the novice is not to eat 
 Mushrooms, unless under the guidance of some one who 
 has had experience. 
 
 All the more important species of Toadstools may be 
 brought under the following classification : 
 
 A. THE HYMENOMYCETES, bearing exposed spores. 
 
 I. The Agaricinece, or Gill-bearing Toadstools. 
 II. The Polyporiece, or Tube-bearing Toadstools. 
 
 III. The Hydnece, or Tooth-bearing Toadstools. 
 
 IV. The Clavariece, or Coral-shaped Toadstools. 
 
 B. THE GASTEROMYCETES, bearing internal spores. 
 
 V. The Puff Balls. 
 
 I. The Gill-bearing Toadstools (Agaricinece) . By far 
 the largest number of Toadstools are included among the 
 Agaricinese. They are distinguished at once from mem- 
 bers of the other divisions by the gills, or lamellce, situated 
 on the under side of the pileus, or umbrella-shaped top. 
 
 THE GILL-BEARING TOADSTOOLS. PRACTICAL STUDIES. 
 
 1. Obtain a number of different kinds of gill-bearing 
 Toadstools. In collecting, dig well into the ground, and 
 secure the entire fructification, together with some of the 
 mycelium. Compare the specimens as to height of the 
 stipe, or supporting stalk, and the shape, diameter, and 
 color of the pileus. ^** BB ** l "* s ' e *^ 
 
 CLARK'S HOT. -11 
 
162 
 
 PRACTICAL BOTANY. 
 
 Find forms that have an annulus, or ring, on the stipe, 
 a short distance below the pileus. This is the remnant 
 of the velum, or veil, which in the button stage enveloped 
 the whole fructification. As the button developed into 
 the full-sized Toadstool, the velum parted. Find remains 
 of it around the edge of the pileus. In some cases the 
 annulus is a true ring, and is movable up and down on 
 the stipe ; in other cases it is firmly attached to the stipe 
 and persists ; in others it disappears. 
 
 Find forms having a volva, or envelope, at the base, ex- 
 tending a short distance up the stipe. Toadstools having 
 
 a volva are to be avoided as poi- 
 sonous. Draw specimens, show- 
 ing all the points mentioned. 
 (See Fig. 94.) 
 
 2. Allow a number of differ- 
 ent kinds of Toadstools to 
 decay. Notice that some shrivel 
 up or decay in the ordinary way, 
 and others turn wholly into a 
 dark, inklike fluid. 
 
 3. Look for Toadstools grow- 
 ing in the woods. Dig up some 
 with considerable earth clinging 
 to the bases. Carefully pick 
 this away and notice the thread- 
 like root portions. These threads are the real plant. 
 They constitute the mycelium. Examine some of the 
 threads under the microscope. 
 
 4. Compare the gills of the different species. In some 
 they extend from the edge of the pileus to thejstipe. In 
 others some of the gills extend the entire distance from 
 the edge of the pileus to the stipe, and some extend only 
 part way. In some the gills do not quite reach the stipe. 
 In others they extend part way down on the stipe. In 
 
 Amn.nitn. rubescens. 
 ,.pilens; ^ an _ 
 nulus; V, volva. (After Le 
 Maout and Decaisne.) 
 
THE FUNGI. 163 
 
 some the gills are thin and sharp. In others they are 
 thick and blunt. Draw each different type found, show- 
 ing view of pileus from below. Notice and describe the 
 color of the gills in each different specimen. 
 
 5. Cutting the stipes close to the pileus, allow different 
 kinds of well-matured Toadstools to rest, gills downward, 
 for some time on sheets of paper. The spores will fall 
 out in abundance. Compare them as to color. The cul- 
 tivated Mushroom, Agaricus campestris, has dark purple 
 spores. Forms with white or light-colored spores are in 
 most cases poisonous. Examine the different kinds of 
 spores under high power. 
 
 6. Cut the stipes of different specimens transversely. 
 Notice and record whether the stipe is solid or hollow ; 
 whether it turns dark after being cut ; whether a juice 
 exudes, and, if one does, what its color is. Forms having 
 a juice, except those having a red juice, are believed to be 
 poisonous. 
 
 7. Cut vertically through a specimen that has both 
 volva and annulus so as to show a section through the 
 entire Toadstool from the base of the stipe to the top of 
 the pileus. Draw. 
 
 8. Make longitudinal microscopic sections of the stipe. 
 For this purpose the material must be hardened by treat- 
 ing pieces not more than half an inch square and quarter 
 of an inch thick with chromic acid for about 24 hours; 
 wash out the acid in water and keep the specimens a day 
 successively in 50, 75, and 90 per cent alcohol. Hold 
 the specimen between two pieces of pith when cutting 
 sections. Examine the sections in dilute glycerine under 
 both low and high powers, and determine that they are 
 made up of interwoven filaments or hyphse. Treat a 
 section with Schultze's solution, which stains normal 
 cellulose blue or violet, and fungous cellulose brown. 
 Is it composed of normal or fungous cellulose ? 
 
164 
 
 PRACTICAL BOTANY. 
 
 9. Make sections of the pileus so as to obtain transverse 
 vertical sections of the lamellae. A Toadstool just ready 
 to open should be used. Examine a 
 lamella under high power. The cen- 
 tral portion is the trama; compare its 
 structure with the structure of the stipe. 
 Outside of the trama are the subhyme- 
 nium and the Tiymenium. Projecting 
 from the hymenium are the basidia, 
 large cells having pointed extensions on 
 the outer ends. In some cases the spores 
 FIG. 95. A portion will be found still attached to these 
 show^g^tifman! P oints 5 in other cases they will have 
 ner in which the fallen off. What is the shape of the 
 
 a P and S th a e ie ceiis r be- s P ores ? These spores are sometimes 
 low it are cells of called basidiospores, from the manner in 
 
 the trama; b is aba- i i j_i i r _< , i 
 
 sidium; c, spores; wnich the J are borne. They are of the 
 the cells projecting type known as gonidia. Between the 
 
 upward between , .,. .. ., .. ,, .., 
 
 the basidia are basidia notice the projecting cells with 
 paraphyses. (After round ends ; these are paraphyses. Draw 
 a portion of the lamella, showing all the 
 parts seen. (See Fig. 95.) 
 
 II. The Tube-bearing Toadstools {Polyporieoe}. The 
 members of this group are also easily recognized. They 
 have the general umbrella shape of the gill-bearing forms, 
 but in place of the gills are numerous tubes arranged verti- 
 cally and parallel to one another. The commonest forms 
 belong to the genus Boletus. This genus includes many 
 poisonous species and a few highly prized edible species. 
 
 THE TUBE-BEAKING TOADSTOOLS. PRACTICAL STUDIES. 
 
 1. Collect as many different kinds of tube-bearing 
 Toadstools as you can find. Compare them as to color, 
 shape, and size of the pileus. Do you find any forms 
 with an annulus? Any with a volva? 
 
THE FUNGI. 165 
 
 2. Cut through the stipes transversely. Are the stipes 
 solid or hollow? If you find any that have juices, state 
 the color of the juices. Do the stipes darken after being 
 cut? 
 
 3. Cut through an entire Toadstool from the base of 
 the stipe to the top of the pileus. Draw. 
 
 4. Obtain spores by allowing some of the Toadstools 
 to remain tube-bearing side down on a sheet of paper. 
 Compare the colors of the spores. Examine them under 
 high powers. 
 
 5. Harden pieces of the tube-bearing portions in chro- 
 mic acid and make microscopic sections transversely 
 through the tubes. Under high power examine the 
 inner edges of the tubes for the hy menial layer, basidia, 
 paraphyses, and spores. 
 
 III. The Tooth-bearing Toadstools (Hydnece). These 
 have the umbrella shape of the two preceding groups, but 
 in place of the gills, or tubes, toothlike points extending 
 downward beneath the pileus. They are not very abun- 
 dant. They are said to be nonpoisonous, but are not 
 much sought after for food, with the exception of one or 
 two species, on account of their disagreeable bitter taste. 
 
 IV. The Coral-shaped Toadstools (Clavariece). These 
 are readily recognized from their shape. They are not 
 abundant. They are not poisonous, and are esteemed as 
 food. 
 
 V. The Puff Balls. These constitute only one of the 
 groups of the Gasteromycetes. They are closely related 
 to the Toadstools, though they present marked points of 
 difference. They are produced by a subterranean myce- 
 lium which decays from the base of the fructification as it 
 matures, and leaves the latter as a loose ball on the sur- 
 face of the ground. This ball is wholly inclosed. The 
 interior is at first white, but as it matures becomes one 
 mass of black spores. The Puff Balls are not poisonous, 
 
166 PRACTICAL BOTANY. 
 
 with the possible exception of one common species, and 
 are eaten when young and before the spores have begun 
 to turn dark. 
 
 References for Reading. Goebel's " Classification of Plants," pp. 
 131-139; Vines' "Text-Book of Botany," pp. 310-320; Bennett and 
 Murray's " Cryptogamic Botany," pp. 388-399; Parker's "Elementary 
 Biology," pp. 191-193; Bower's "Practical Botany," pp. 453-461; 
 Dodge's Practical Biology," pp. 301-307; Carpenter's "The Micro- 
 scope," pp. 575, 576; Gibson's "Our Edible Toadstools and Mush- 
 rooms " ; article by Gibson on Edible Mushrooms, in Harper's 
 Magazine for August, 1894 ; Cooke's " Introduction to the Study 
 of Fungi," pp. 119-163; Farlow's u Notes for Mushroom Eaters"; 
 Palmer's " About Mushrooms." 
 
VI. 
 
 THE BRYOPHYTES. 
 
 A higher differentiation of root, stem, and leaf distin- 
 guishes the Moss plants from plants of the preceding sub- 
 divisions. There is a distinct alternation of generations 
 from the gainetophyte, the ordinary Moss plant, to the 
 sporophyte, which develops in the archegonium on the 
 female gametophyte and there produces spores. The 
 differentiation into stem and leaf is outwardly quite well 
 marked, but the inner structure shows only slight progress 
 in these directions. Roots are represented by unicellular 
 or multicellular filaments called rhizoids. The stem shows 
 a decided tendency to. the formation of fibro vascular bun- 
 dles. Gonidia are not formed, but gemmce reproduce some 
 of the plants of this subdivision vegetatively. There are 
 no saprophytes or parasites. All the Bryophytes are 
 chlorophyl-bearing plants of holophytic nutrition. Much 
 moisture is necessary to their vigorous life ; hence they 
 are found in shady damp places on the ground, on the 
 lower parts of the trunks of trees, and on rocks. There 
 are two classes. 
 
 CLASS I. THE LIVERWORTS (Hepaticae). 
 CLASS II. THE MOSSES (Musci). 
 
 CLASS I. The Liverworts. The Liverworts are for the 
 most part low, flat, thalloid plants. They grow in moist 
 locations on the earth and on the rocks along streams and 
 ditches, and in great abundance on the soil in damp 
 greenhouses. The common Liverwort, Marchantia poly- 
 
 K>7 
 
168 
 
 PRACTICAL BOTANY. 
 
 FIG. 96. A mass of Marchantia poly- 
 morpha bearing the male inflores- 
 cence. (After Bennett and Murray.) 
 
 morplia, is one of the largest of the class and is well suited 
 for study. 
 
 There are two modes of asexual reproduction. By one, 
 buds or gemmae are formed in little cups or cupules which 
 
 grow on the upper surface 
 of the frond ; these, when 
 ripe, fall out and are scat- 
 tered over the ground, 
 where they take root and 
 produce new plants. By 
 the other mode new and 
 separate plants result from 
 the dying away of the old- 
 est portions of the frond. 
 The frond branches dicho- 
 tomously ; as the older 
 part dies, the branches 
 become separated, and each continues its existence as a 
 new plant. Reproduc- 
 tion by this mode is said 
 to be by innovation. 
 
 There is considerable 
 variation in the different 
 orders of Liverworts in 
 the positions of the or- 
 gans of reproduction. In 
 some orders both the 
 male and female inflores- 
 cences are borne on the 
 same plant ; that is, the 
 Liverwort is monoecious. 
 In other orders the plant 
 is dioecious. In the com- 
 mon Liverwort the male inflorescence is borne on umbrella- 
 shaped branches. The branches rise an inch or more from 
 
 FIG. 97. An antheridium of Marchantia 
 polymorpha. The antheridia are borne 
 on the upper surface of the umbrella- 
 shaped branches seen in Fig. 96. B 
 are antherozoids that have been set 
 free. (After Goebel.) 
 
THE BRYOPHYTES. 169 
 
 the frond, and the antheridia grow from the upper surface 
 of the scalloped-edged circular top. The antheridia are 
 modified hairs. The female inflorescence is borne on 
 branches of other plants of about the same height as the 
 male branches. The tops differ in that the lobes are 
 slender and are cut well in toward the center. The top 
 has been compared to a wheel without the rim. The 
 archegonia are borne on the under side, concealed in tis- 
 sues in the grooves of the rays. These are also modified 
 hairs. (See Figs. 96, 98, and 99.) 
 
 The antherozoids, borne in the antheridia, swim out 
 when there is moisture on the plant drops of dew are 
 sufficient and find their way to the archegonia. Pass- 
 ing down through the neck, they come in contact with the 
 egg cells, which they fertilize. A spore fruit results, and 
 the spores develop by fission of cells into small and simple 
 growths called protonemce, from which new plants arise. 
 (Figs. 97 and 101.) 
 
 COMMON LIVERWORT. 1 PRACTICAL STUDIES. 
 
 1. Examine with the naked eye a considerable number 
 of specimens of Liverwort. It is not possible to find all 
 the different stages of development at some seasons of the 
 year, and alcoholic material must then be used in part of 
 the work. Find, if possible, plants bearing cupules, some 
 bearing the male inflorescence, and some bearing the female 
 inflorescence. Notice how the plants branch. Examine 
 the end of each branch. What do you observe ? Do the 
 two parts which result from a given division develop into 
 branches of equal size ? Do you find a midrib ? If so, 
 can you trace it along the main stem of the thallus and 
 along the branches ? Measure and state the length and 
 breadth of several plants. Observe the color. Are all 
 1 Similar Practical Studies may be made of any other species of Liverwort. 
 
170 
 
 PRACTICAL BOTANY. 
 
 parts of the same color ? Carefully remove some of the 
 plants from the earth on which they grew and wash off 
 the dirt. Compare the proximal and distal ends. Do 
 you find that the stem rises as the continuation of a true 
 root? Notice the numerous hairy rhizoids. What color 
 
 FIG. 98. Portions of plants of Marchantia polymorpha showing the dicho- 
 tomous division. E shows two cases of the female inflorescence, cupules 
 on the left-hand branch, and rhizoids at the base ; M bears cupules. 
 
 are they ? Where are they situated ? Observe the cu- 
 pules on some of the plants. What is their shape ? Are 
 they sessile or raised on stalks ? Notice in them the little 
 buds or gemmae. Draw specimens, showing as many of 
 the points observed us you can. 
 
 Examine plants bearing male or antheridial branches. 
 
THE BRYOPHYTES. 
 
 171 
 
 Where on the thallus are the male branches borne? Meas- 
 ure and state the length of the pedicel, or stalk, in several 
 specimens ; also the diameter of the head, or receptacle. 
 Draw a receptacle seen directly from above, showing the 
 exact number of lobes. Notice grooves on the pedicel. 
 How many are there and where are they situated ? 
 
 Examine plants bearing the female or archegonial 
 branches. Where on the thallus are the female branches 
 borne ? What is the greatest length of pedicel that you 
 find? Do you find grooves on the pedicel? If so, what 
 is their number and where are they situated ? Draw a 
 receptacle seen from above, showing the number of lobes. 
 Also draw plants, showing the male and female inflo- 
 rescence. 
 
 2. With a magnifying glass examine the upper surface 
 of a thallus for rhomboidal areas or areolse. Observe that 
 there is a small opening in the 
 
 center of each areola. This is 
 a stoma, or breathing pore, and 
 is the first instance thus far met 
 of the occurrence of an organ 
 that is common to all the higher 
 plants. Do you find areolae and 
 stomata on the under surface of 
 the thallus ? Among the rhi- 
 zoids find purple and colorless 
 scales. On what parts of the 
 thallus do you find each ? Draw 
 some of the scales and hairs. 
 
 3. Study the structure of the 
 thallus, using first low, then 
 
 high power. Strip off some of the epidermis of the upper 
 surface and examine the areolee, epidermal cells, and 
 stomata. Draw a stoma as seen under high power, 
 showing the number and arrangement of the exterior 
 
 FIG. 99. A female inflores- 
 cence of Marchantia poly- 
 morpha. The archegonia are 
 borne among the hairs on the 
 under surface, which is pre- 
 sented to view in the figure. 
 (After Goehel.) 
 
172 
 
 PRACTICAL BOTANY. 
 
 supplementary guard cells and some of the surrounding 
 epidermal cells. Focus down and notice the number, 
 
 shape, and arrange- 
 ment of the true 
 guard cells. Draw. 
 In a similar way 
 study the epidermis 
 of the lower surface 
 of the thallus. Draw 
 a few of the epider- 
 mal cells, selecting 
 some that show how 
 a hair originates. Do 
 you find stomata ? 
 Remove some of the 
 
 FIG. 99 a. A portion of the epidermis of the 
 upper side of Marchantiapolymorpha, show- 
 ing areolse and stomata. (X 480.) 
 
 hairs and study them under high power. Find two kinds, 
 the fine silky rhizoids, 
 situated directly under the 
 midrib, and coarser hairs, 
 showing projections extend- 
 ing inwards from a spiral 
 constriction. The outline 
 of the coarser hairs as seen 
 in optical section appears 
 scalloped. (Fig. 102.) 
 
 Imbed a piece of the thal- 
 lus in pith and cut trans- 
 verse sections. Mount some 
 in water and some in alco- 
 hol. Draw an entire section 
 and indicate each of the 
 following parts on it. No- 
 tice the row of colorless 
 cells of the upper epidermis. Hunt along this row for a 
 section through a stoma. If one is found, draw it. Below 
 
 Fio. 100. A vertical section through 
 a plant of Marchantia polymorpha, 
 showing a stoma at S, the air cav- 
 ity below it, and scales at EE. 
 
THE BRYOPHYTES. 173 
 
 the epidermal cells, notice the rows of green parenchyma 
 containing numerous chlorophyl bodies. Determine if 
 starch is present. In the green parenchyma, find air cavi- 
 ties lined with bright green cells. A stoma connects each 
 air cavity with the outer air, but may not lie in the plane 
 of the section. Below the green parenchyma, notice color- 
 less parenchyma extending to the epidermis of the lower 
 side of the thallus. Can you find hairs and scales growing 
 from the lower epidermis ? If so, draw them. 
 
 4. With a razor cut off two cupules. Mount one face 
 up, the other face down, in water, pressing on the cover 
 glass to flatten them down. Notice on the first, under 
 low power, a fringe of teeth ; then examine one of the 
 teeth under high power. What is its shape? Do you 
 find any hairs ? Using the second specimen, examine the 
 lower surface of the mount for hairs. 
 
 Imbed in pith a piece of the thallus bearing cupules 
 and make sections passing vertically through a cupule. 
 Draw the sections under the low power. Examine under 
 low power for gemmae. Under high power, trace the 
 development of the gemmse. They should be found in 
 all stages of growth. 
 
 Examine mature gemmae under both low and high 
 powers. Make out the scar which shows where the 
 gemma was attached to its stalk ; also the two vegetative 
 notches half way up the sides. Draw a gemma. Study 
 also gemmae that have begun to germinate. Gemmae that 
 have been in water for a number of days should be used. 
 Compare with the gemmae that have not germinated. 
 Draw. Sow some gemmae on sand in a moist chamber. 
 Keep in the sunlight. They will sprout in a few days. 
 Watch their development until the characteristic struc- 
 tures of the Liverwort are apparent ; make drawings at 
 intervals. 
 
 5. Study the structure of the antheridial branch. Ex- 
 
174 
 
 PRACTICAL BOTANY. 
 
 rnr, . _. 
 
 amine the pedicel with a magnifying glass and notice the 
 rhizoids and leaf scales along the grooves. Examine a 
 cross section of the pedicel under low power. Draw. 
 
 Examine the same sec- 
 tion under high power, 
 noticing particularly the 
 rhizoids and leaf scales 
 as seen in section. 
 
 With a magnifying 
 glass observe the anther- 
 idia on the upper sur- 
 face of the receptacle. 
 Imbed in pith and make 
 vertical sections through 
 the central part of the 
 receptacle. Under high 
 power find the anther- 
 idia in their somewhat 
 ovoidal cavities. Draw. 
 Near the antheridia one 
 celled, hairlike paraphy- 
 ses may be found in 
 specimens that are not 
 too mature. In the case 
 of mature antheridia, 
 antherozoidsmaybe seen 
 in the cells or swimming 
 in the water. This ob- 
 servation is difficult ; 
 the antherozoids may, 
 perhaps, be obtained by 
 placing a drop of water 
 on the top of an anther- 
 idium, the upper part 
 of which has been 
 
 FIG. 101. The archegonium of Marchantia 
 polymorpha in different stages of its 
 growth. I-V show it before fertiliza- 
 tion. The antherozoids, which are pro- 
 duced in the antheridia, and which are 
 shown in Fig. 97, enter at x, pass up 
 through the long neck, and fertilize the 
 oosphere. A sporogonium results. This 
 is seen in different stages in VII and 
 VIII, which also show the shriveling of 
 the cells of the neck that occurs after 
 fertilization. IX shows a developing 
 sporogonium filled with spores and 
 elaters; a is the neck of the arche- 
 gonium wholly withered up. (After 
 Goebel.) 
 
THE BHYOPHYTES. 
 
 175 
 
 free from wetting for several days ; after a few minutes 
 
 transfer the drop of water to a slide by inverting the 
 
 antheridium on the slide. It is to 
 
 be remembered that motile an- 
 
 therozoids can be found only at 
 
 the seasons of the year when the 
 
 plants are at the right degree of 
 
 maturity. 
 
 Compare the upper and lower 
 surfaces of the male receptacle 
 with the corresponding surfaces 
 of the thallus. 
 
 6. Study the structure of the 
 archegonial branch. With a mag- 
 nifying glass examine the grooves FlG 102 ._c e iis from Mar- 
 on the under side of the receptacle. 
 Imbed a receptacle in pith, make 
 vertical sections, and examine with 
 high power for archegonia. These 
 are shaped something like a flask 
 with a long neck. The archegonia 
 may also be obtained for examina- 
 tion by scraping out the contents 
 of one of the grooves into a drop 
 of water. Draw an archegonium, 
 showing clearly its stalk, body, and neck. Try to make 
 out the internal structure of an archegonium, studying as 
 many specimens of different stages of development as can 
 be found. Crush under the cover glass some of the fully 
 matured archegonia ; study the spores and elaters. The 
 latter are marked by delicate spiral bands. Draw both. 
 Crusli a ripe archegonium on a glass slip without mois- 
 ture. Examine under high power, and Avhile looking 
 through the microscope let some one breathe gently on 
 the mass. What happens to the elaters ? What mecharii- 
 
 chantia polymorpha. A, 
 an elater ; A', part of same, 
 showing spiral cell walls ; 
 B, a cell from the plant 
 body showing pitted mark- 
 ings of the cell wall. This 
 is the first instance in as- 
 cending the scale of plant 
 life of a structure very 
 common in the higher 
 plants ; C and D, rhizoids, 
 such as are seen at the 
 base of E, Fig. 98. (After 
 Sachs.) 
 
176 PRACTICAL BOTANY. 
 
 cal purpose may the elaters serve in the distribution of 
 the spores ? 
 
 References for Reading. Goebel's " Classification of Plants," pp. 
 140-163; Vines' "Text-Book of Botany," pp. 324-354; Bennett and 
 Murray's " Cryptogamic Botany," pp. 132-136, 156-171 ; Strasburger 
 and Hillhouse's " Practical Botany," pp. 194-196, 272-277 ; Bower's 
 " Practical Botany," pp. 360-378 ; Dodge's " Practical Biology," pp. 
 308-319; Boyer's "Elementary Biology," pp. 134-139; Carpenter's 
 " The Microscope," pp. 590-594. 
 
 CLASS II. The Mosses. The Lichens, Liverworts, and 
 Mosses are popularly but incorrectly spoken of as Mosses. 
 The true Mosses are distinctly higher in the complexity 
 of their structure than the Lichens and Liverworts. The 
 axis of growth is more erect ; the plant is provided with 
 truer leaves, with rhizoids that closely approach true roots 
 in character, and shows a greater differentiation in the 
 tissues of the stem. The cells on the outside of the stem 
 are elongated, are of a red-brown color, are thick walled, 
 and approach the structure of bark more nearly than any 
 tissues hitherto studied, though the epidermis is very im- 
 perfectly developed. Again the cells in the center of the 
 stem are thin walled, and are aggregated into a distinct 
 axial bundle, which, simulates in function, and to some 
 extent in structure, the fibro vascular bundles of all the 
 higher plants. The growth of the stem is by the division 
 of an apical cell which grows concealed in the leaves. 
 This cell has the shape of a triangular pyramid with the 
 apex pointing down. In dividing, a slice splits off from 
 one of the sides of the pyramid ; then a slice splits off 
 from a second side ; then one from the third side, the 
 pyramid growing to its original size before each nssion. 
 Each of the slices divides into many cells, which develop 
 into the tissues of the stem, leaves, and rhizoids. 
 
 Mosses are reproduced asexually by different modes of 
 budding, but not, so far as is known, by asexual spores. 
 
THE BRYOPHYTES. 177 
 
 In the sexual reproduction Mosses are either monoecious 
 or dioecious. Antherozoids swim to and fertilize the egg 
 cells produced in archegonia growing on the same or on 
 another plant. The result of this fertilization is the spo- 
 rophyte form of the plant, which develops in situ in the 
 archegonium. The capsules containing the egg cells be- 
 come filled with spores that closely resemble the asexual 
 spores of some other plants. The spore, in germinating, 
 produces a branching filament known as aprotonema, which 
 gives off lateral buds from which new Moss plants grow. 
 
 POLYTRICHUM COMMUNE. 1 PRACTICAL STUDIES. 
 
 Polytrichum commune, or Hairy-cap Moss, is one of the 
 largest and most common of the Mosses. It grows in 
 abundance in dark green patches in the woods, fields, and 
 along the road sides. The plants are from three to six 
 inches tall. The stems are usually simple, but sometimes 
 are forked. The leaves are from half to two thirds of an 
 inch long. (See Fig. 103.) 
 
 1. With the naked eye examine some plants of Polytri- 
 chum commune. Find male or antheridial plants, recog- 
 nized by a starlike cluster at the top. (Fig. 103, M.^ 
 These clusters develop in the spring, but remain conspic- 
 uous throughout the season. Some male branches show 
 two or more clusters. After the formation of the lower 
 cluster, the apical bud continued to develop and formed 
 other clusters. This is known as prolification. Find an 
 instance of it. (See Fig. 103, P.) 
 
 Find a female or archegonial branch. In the spring 
 the archegonium is concealed among the leaves of a stem 
 that is more pointed than the male stem. After fertiliza- 
 tion the female stem sends up a long, slender red shoot, or 
 
 1 Similar Practical Studies might be made of any other Moss, as Sphag- 
 num, Mnium, Bryum, Atrichum, orBartramia. 
 CLARK'S BOT. 12 
 
FIG. 103. Poly trichum commune. S, sterile plant; If and P, male plants; 
 F, female plant; H, seta ; C, sporangium ; P shows prolitication. 
 
 178 
 
THE BRYOPHYTES. 179 
 
 seta, which bears at its top a capsule. (See Fig. 103, F.) 
 A calyptra, or cap, with pointed apex, envelops the capsule 
 with long silky hairs. 
 
 Find also sterile branches. These are recognized by 
 their pointed tops and the lack of the characteristics 
 already described for the male and the female branches. 
 Note the position and arrangements of the leaves and rhi- 
 zoids on each of the three kinds of branches. Draw each. 
 
 2. Imbed in pith, celloidin, or 
 paraffin, pieces of the root end of the 
 stem and cut cross sections. Study 
 the structure under both low and 
 high power. Notice the imperfectly 
 differentiated epidermis, the cells 
 with thickened wall next within the 
 epidermis, and the somewhat distinct 
 
 bundle of thin-walled cells, the axial Fm m _ Cross section 
 bundle, in the center. (See Fig. 104.) of the stem of the MOSS, 
 
 T^ M j.i i i J.T, Bryum roseum, show- 
 
 Describe the rhizoids as seen on the ^ simple differenti . 
 section. Draw the entire section. ation of the tissues at 
 
 TT, nil,? i^ i J_T the center to form a 
 
 Run Schultze's solution under the fib rovascuiar bundle. 
 
 COVer glass. This Solution Stains The imperfect develop- 
 
 ._ , _. , ,. -~ ment of the bark and 
 
 llgmfied Cellulose yellow. Do yOU the appearance of the 
 
 find both normal cellulose and ligni- rhizoids are also shown. 
 
 (After Goebel.) 
 
 fied cellular tissue r 
 
 Mount some of the rhizoids in water and examine under 
 low power. State how the cells are arranged. Do the 
 rhizoids branch? Draw a rhizoid. 
 
 3. Examine a leaf under low power. Draw the entire 
 leaf. Do you find a midrib? Notice the teeth or spines 
 on the margin forms of plant hairs. Under the high 
 power draw one of the teeth and a few of the adjacent 
 cells. If dried material is used, the leaves should be 
 soaked in dilute caustic potash for twenty-four hours 
 previous to this observation to render them transparent. 
 
180 
 
 PRACTICAL BOTANY. 
 
 Boiling the leaves in Schultze's macerating mixture serves 
 the same purpose. Also draw, under high power, a few 
 cells from the wide base portion of the leaf. Have you 
 
 found stomata ? Exam- 
 ine pieces of the epider- 
 mis torn from the stem 
 for stomata. Do you 
 find them ? Stomata 
 are sometimes found 
 on the midribs of the 
 leaves and on the setae. 
 Under low power 
 draw one of the leaves 
 or bracts from an an- 
 theridial head. Draw 
 a few cells of the bract 
 as seen under high 
 power. 
 
 Examine under low 
 power cross sections of 
 the leaf. The sections 
 are best cut from pieces 
 of the upper, leafy 
 portion of the stem 
 imbedded in celloidin. 
 Some of the sections of 
 the leaves will be nearly 
 or quite transverse. Locate the axial bundle of the mid- 
 rib. Notice the lamellae on the upper surface. Draw the 
 entire section. Also draw some of the lamellas as seen 
 under high power. 
 
 4. If material gathered in the spring can be studied, 
 dissect a male head in water and try to make out, using 
 both low and high powers, the antheridia somewhat 
 thick, ovoidal bodies made up of polygonal cells and 
 
 FIG. 105. A, antheridia and filiform and 
 spatulate paraphyses of Polytrichum 
 commune ; B., C, and I), antherozoids of 
 same in their cysts, and variously mag- 
 nified. (After Thuret.) 
 
THE BRYOPHYTES. 
 
 181 
 
 filiform and spatulate paraphyses. Draw. If fresh mate- 
 rial is employed, crush the antheridia by pressure on the 
 cover glass, and try to see the flagellated antherozoids. 
 This is difficult. The antheridia and paraphyses may also 
 be studied in vertical sections cut from a male head im- 
 bedded in celloidin. (See Figs. 105, 106, 107.) 
 
 FIG. 106. Vertical section through the top of a male plant of Funaria hygro- 
 
 metrica, showing how the antheridia are borne, a is a young antheridium ; 
 
 & is a more mature antheridium seen in section ; paraphyses are seen at c. 
 
 (After Goebel.) 
 FIG. 107. An antheridium of the Moss, Funaria hygrometrica, allowing the 
 
 antherozoids to escape. At 6 is an antherozoid in its cyst; at c the anthero- 
 
 zoid has been wholly set free. (After Goebel.) 
 
 5. Study the female head in material collected in the 
 spring ; fresh material is to be preferred. Tease out a 
 head in a drop of water and find flask-shaped archegonia 
 with short foot stalks and long, slightly curved necks. 
 Draw. Focus into the neck and make out the canal 
 
182 
 
 PRACTICAL BOTANY. 
 
 FIG. 108. A is a vertical 
 section through the top of 
 a female plant of Funa- 
 ria hygrometrica, showing 
 how the archegonia are 
 borne; B is an archego- 
 nium more highly magni- 
 fied. The antherozoids 
 seen in Fig. 107 pass down 
 through the neck, m, and 
 fertilize the egg cell, which 
 is seen centrally located 
 at 6 ; C is the neck of the 
 archegonium more highly 
 magnified. (After Goe- 
 bel.) 
 
 leading from its top down to the 
 oosphere or egg cell in the central 
 portion of the archegonium. (See 
 Fig. 108.) 
 
 6. Study the matured fruit. 
 After the oosphere is fertilized, it 
 is raised on a long, slender stalk, 
 or seta. Draw a capsule with the 
 calyptra still on and one from which 
 it has been removed. Remove the 
 operculum, or lid, and draw it as 
 seen from above. Beneath the 
 operculurn the mouth of the spo- 
 rangium, or urn, is covered with a 
 delicate diaphragm surrounded by 
 a peristome or fringe of teeth. 
 With a razor cut off the diaphragm 
 and peristome, place them top side 
 up on a dry slide, and, while exam- 
 ining under low power, let some 
 one breathe gently on them. The 
 fringe of teeth is hygrometric, i.e., 
 when moisture touches it, it exe- 
 cutes movements. These motions 
 are believed to be a means for 
 scattering the spores from the urn. 
 Examine some of the spores. 
 
 References for Reading. Parker's " Elementary Biology," pp. 332- 
 343; Goebel's "Classification of Plants," pp. 163-188; Vines' "Text- 
 Book of Botany," pp. 354-371 ; Carpenter's " The Microscope," pp. 
 594-599 ; Strasburger and Hillhouse's " Practical Botany," pp. 190- 
 195, 277-286; Bower's "Practical Botany," pp. 341-359; Arthur, 
 Barnes, and Coulter's "Plant Dissection," pp. 84-102; Lesquereux 
 and James' " Mosses of North America " ; Strasburger, Noll, Schenck, 
 and Schimper's "Lehrbuch der Botanik," pp. 335-349. 
 
VII. 
 
 THE PTERIDOPHYTES. 
 
 The plants of this subdivision approach the common 
 Flowering Plants in their structure much more nearly 
 than any thus far considered. 
 There is a marked differen- 
 tiation of tissues. True vas- 
 cular bundles give support 
 to the aerial stalks, and serve 
 to convey the fluids for the 
 nourishment of the plant. A 
 slight tendency to the forma- 
 tion of these differentiated 
 structures has already been 
 noted in the case of the stems 
 of Mosses, but no true vessels 
 are formed in them. From 
 this fact, that their structure 
 is wholly cellular, the plants 
 of the preceding subdivisions 
 are called cellular crypto- 
 gams. Because of the pos- 
 session of woody bundles, 
 and because one method of 
 reproduction is by spores and 
 not by seeds, the Pterido- 
 
 FIG. 109. Pteris aqulhna. rh, rhi- 
 zome; ab, apical bud; I 1 , present 
 year's leaf; I 2 , withered leaf of 
 last year ; p, a pinna ; x, one of 
 the younger pinnae, which is seen 
 more highly magnified at B. 
 (After Sedgwick and Wilson.) 
 
 phytes are called vascular 
 cryptogams. In the Ferns 
 and their allies fully developed fibrovascular bundles, 
 made up largely of spiral and scalariform vessels and 
 
 183 
 
184 
 
 PRACTICAL BOTANY. 
 
 
 FIG. 110. Prothallium of a Fern. Among the rhi- 
 zoids on the lower part of the figure are several 
 antheridia. Above them, near the sinus of the 
 heart, are archegonia. A single antheridium 
 with escaping antherozoids is seen at B ; an 
 archegonium is seen in section at A, showing 
 the egg cell and the tube leading to it. Through 
 the tube a drop of mucilage is being discharged. 
 (After Luerssen.) 
 
 transverse sections of the stems. There 
 differences in the modes of reproduction, 
 
 sieve tubes, are 
 found. Here, too, 
 for the first time, 
 a distinct, well- 
 differentiated epi- 
 dermis occurs, 
 with stomata, or 
 breathing pores, 
 resembling those 
 of the higher 
 plants. 
 
 In size there is 
 also much ad- 
 vance, for some of 
 the Ferns in tropi- 
 cal climates reach 
 the size of trees. 
 In the arrange- 
 ment of the wood 
 there is, however, 
 a marked differ- 
 ence from the 
 arrangements in 
 both monocotyle- 
 donous and dico- 
 tyledonous plants 
 of the highest 
 branch. This is 
 especially notice- 
 able in the shapes 
 and positions of 
 the fibrovascular 
 bundles as seen in 
 are also marked 
 
THE 1TEKIDOPHYTES. 185 
 
 The alternation of generations is clear and distinct. The 
 ordinary form of the plant is the sporophyte. When the 
 spores germinate, there is first formed a protonema which 
 develops into a small thalloid leaf called the prothallium. 
 This is usually about an eighth of an inch in diameter. This 
 is the gametophyte ; it is inconspicuous and is short lived. 
 The prothallia may be obtained for study from the damp 
 flower pots, walls, or soil of greenhouses in which Ferns 
 are cultivated, or they may be gfowri by sowing the Fern 
 spores on moist soil, kept protected by a bell glass, and 
 exposed to suitable conditions of light, heat, and moisture. 
 It requires from six to ten weeks to grow the prothallia 
 from the spores. (See Fig. 110.) 
 
 If the under side of one of these heart-shaped prothallia 
 be examined under the microscope, special differentiations 
 of the cells will be found near the sinus of the heart ; 
 these are the archegonia or pistillidia; they are rounded 
 aggregations of cells, with a large, centrally situated cell 
 that divides into two. Of these two cells, the lower 
 develops into the egg cell, or oosphere ; the upper de- 
 velops into a tube which becomes filled with a mucilagi- 
 nous substance that is afterwards discharged, leaving the 
 passage to the oosphere open. (See Fig. 110, A.) 
 
 More distant from the sinus of the prothallium are the 
 antheridia, situated among the root hairs. In these, spi- 
 rally coiled antherozoids are developed, being finally dis- 
 charged by the rupture of the cell wall. Accompanying 
 each antherozoid is a small cell, the use of which is not 
 understood. Each antherozoid is provided with cilia, by 
 means of which it swims about when the prothallium is 
 wet. (See Fig. 110, .#.) It may in this way pass to other 
 prothallia, where, by fertilizing the oosphere, a hybrid 
 variety is produced. If the antherozoids come in con- 
 tact with the mucilage around the mouth of an archego- 
 nium, the mucilage aids in directing them into the tubu- 
 
186 PRACTICAL BOTANY. 
 
 lar neck leading to the oosphere. By the fertilization of 
 the oosphere a new plant is produced. This plant in turn 
 produces spores. The life history, as just detailed, is 
 believed to be practically the same in all Pteridophytes,^ 
 though it has not been fully observed in all the species. 
 There are three classes. 
 
 CLASS I. THE TRUE FERNS (Filicince). 
 CLASS II. THE HORSETAILS (Equisetince). 
 CLASS III. THE CLUB MOSSES (Lycopodince). 
 
 CLASS I. The True Ferns. Two groups of plants 
 included here are heterosporous, i.e., they have two kinds 
 of spores, female macrospores and male microspores. These 
 are the Salvinacece and Marsiliacece. All others are homo- 
 sporous or isosporous, i.e., they bear only one kind of spore. 
 
 The Ferns, in the narrower sense of the term, are dis- 
 tinguished at once from the other members of this branch 
 by the luxuriance of their leaves. The stem, or rhizome, 
 is underground and develops by the formation of a new 
 bud at one end each year, while it dies away at the older 
 end so as about to keep pace with the new growth. In 
 the spring the young fronds may be seen unrolling them- 
 selves, for they are coiled up, or circulate, in the bud. 
 Ferns vary in height from an inch up to many feet, the 
 larger ones, in tropical climates, often raising the rhizome 
 out of the ground to form the trunk of a tree with a tuft 
 of fronds at its top. 
 
 On account of the delicate beauty of their fronds, Ferns 
 offer a very attractive field for study. It is estimated 
 that there are from 3000 to 4000 species in all the world. 
 They flourish most abundantly in the torrid zone, decreas- 
 ing in number and size as one passes from the equator 
 towards the poles. Only 26 species are known to grow 
 within the limits of the Arctic zone, and only 67 species 
 are recorded for the whole of Europe. For North America. 
 
THE PTERIDOPHYTES. 187 
 
 Underwood describes 158 species in " Our Native Ferns 
 and Their Allies." No single locality furnishes a very 
 large number of species. 
 
 The Ferns, in the broader sense, include the True 
 Ferns (far the largest number), the Salvinacece, and the 
 Mars iliac ece. The Marattiacece, or Ringless Ferns, which 
 are exotic, and found only in greenhouses, and the 
 Ophioglossece are closely related. The Ophioglossece, or 
 Adder Tongues, differ from other members of the branch 
 in that the leaves are not circinate in the bud, but are 
 straight or folded, and in their spore cases, which are 
 without rings. They are represented in this country by 
 the Adder Tongues and the Moon worts, Botrychium. 
 
 THE EAGLE FERN. 1 PRACTICAL STUDIES. 
 
 The Eagle Fern (Pteris aquilina), or Brake Fern, is 
 probably the most widely distributed of all the Ferns. 
 It grows in all climates, from the torrid zone to the Arctic 
 circle. It is known to thrive as high as 9000 feet above 
 the sea level. In some tropical countries it is said to 
 reach a height of 12 to 14 feet. In New England 
 it varies in height from a few inches in dry barren 
 localities to three or five feet in rich-soiled moist places. 
 Under favorable conditions it grows in such abundance as 
 to form brakes, or thickets, whence the common name. 
 
 This Fern is easily recognized from the fact that the 
 frond appears to be triply divided. An examination of 
 the frond shows that this is in appearance only, for the 
 two lower branches differ from the pairs above only in 
 size and in being set somewhat forward on the leaf stalk. 
 Specimens for examination should include as much of the 
 underground portions as can be obtained, for it is to be 
 
 1 Practical Studies of almost any other Fern could be added. Any 
 species of Osmunda, Poly podium, or Adiantum would be good. 
 
188 
 
 PRACTICAL BOTANY. 
 
 remembered that the stem is an 
 underground rootstock, or rhi- 
 zome, and that what is appar- 
 ently an aerial stem is really 
 the petiole, or stipe, of the leaf. 
 Care should be taken to injure 
 the rhizome as little as possible 
 in removing it from the ground. 
 1. With the naked eye make 
 an examination of an entire 
 plant. What is the color of 
 the rhizome? Notice the lat- 
 eral ridges. Does the rhizome 
 branch? How many leaf stalks 
 grow on a branch? Where on 
 the rhizomes are the leaf stalks 
 borne ? Do you find remains 
 of the leaves of previous years 
 still attached to the rhizome ? 
 Notice the apical bud at the 
 end of the rhizome. If the speci- 
 men was dug up in the spring, 
 the apical bud is from half to 
 three fourths of an inch from 
 the base of the season's stipe ; 
 later in the season, this bud will 
 have grown into an upright rudi- 
 mentary stipe which will de- 
 velop the following season, and 
 a new apical bud will have 
 formed at the end of a new 
 growth of the rhizome. It is 
 
 FIG. 111. Pt.eris aquillna. A, a portion of the branching underground 
 stem or rhizome with fine roots ; B, a young leaf ; C, a mature leaf . (After 
 Sedgwick and Wilson.) 
 
THE PTERIDOPHYTES. 
 
 189 
 
 thus seen that the rhizome increases in length each season 
 only half or three fourths of an inch. Notice the roots. 
 Here true roots are first met in ascending the scale of 
 plant life. The rhizoids of all the lower plants have been 
 single cells or unbranched linear aggre- 
 gates of cells. The roots of Ferns are 
 solid aggregates ; they have an epider- 
 mis, and are made up of systems of 
 tissues closely resembling the tissues 
 of the stem. Notice that the roots 
 branch. Do you find hairs on the 
 roots? With a sharp knife make a 
 transverse section of the rhizome. 
 What is the color of the ground tis- 
 sue the fundamental parenchyma? 
 Notice the brownish tissue surrounding 
 the rhizome just inside the epidermis; 
 it is composed of lignified cellulose 
 and is known as sclerotic parenchyma 
 or sclerenchyma. Notice two well- 
 defined, almost black areas farther 
 within the stem ; they are made up of 
 very hard, strongly lignified cellulose, 
 and are known as sclerotic prosenchyma. Around and be- 
 tween these areas the fibro vascular bundles can be faintly 
 seen by the naked eye as more or less oval areas of tissues 
 slightly darker than the fundamental parenchyma. Draw 
 the section. 
 
 Notice that the stipe is small near the origin on the 
 rhizome, enlarges considerably as it approaches the surface 
 of the ground, and diminishes gradually as it rises above 
 the surface. Of what advantage to the plant is the 
 enlargement? Cut a cross section of the stipe. Draw it. 
 Notice the appearance of the tissues in the section. An 
 imagined resemblance of these tissues to an eagle with 
 
 FIG. 112. Cross section 
 of the root of Pterls 
 aquilina. In the cen- 
 ter is the fibrovascu- 
 lar bundle ; the dense, 
 dark tissue next to the 
 bundle is sclerotic pa- 
 renchyma ; outside of 
 this is fundamental 
 parenchyma, which, 
 together with the 
 imperfectly formed 
 bark, is often broken 
 away in the growth of 
 the root as is seen on 
 the left of the figure. 
 
190 
 
 PRACTICAL BOTANY. 
 
 outspread wings was the origin of the name Eagle Fern. 
 All above the lowest branches of the stipe is known as 
 the lamina or leaf. The leaf is pinnately and bipinnately 
 divided. Find, if possible, a fruiting frond. The spo- 
 rangia are borne around the margin of the under side of 
 the frond, protected by an indusium formed by the folding 
 over of the edge of the leaf. 
 
 Draw a plant of Pteris, showing distinctly all its differ- 
 ent parts. 
 
 2. Examine a longitudinal horizontal section of an apical 
 bud cut in the plane of the lateral ridges from a specimen 
 imbedded in celloidin. Find the apical 
 cell in the hollow at the end ; as seen 
 in section it is a triangle with rounded 
 base. (See Fig. 113, A.) This cell 
 divides by the splitting off of cells 
 first from one side, then from the 
 other side. These cells are known as 
 segmental cells ; they divide and sub- 
 divide to form new cells. Every cell 
 in the rhizome has originated through 
 the segmental cells from the apical 
 cell. It requires care and skill to se- 
 cure sections showing the apical cell. 
 
 The cells which extend for a short 
 distance within and around the seg- 
 mental cell are thin walled and make 
 up an actively growing tissue known 
 as the apical meristem. As this tissue 
 continues to grow, its cells become differently differen- 
 tiated and develop into the various tissues of the rhizome. 
 Examine a vertical longitudinal section of an apical 
 bud. The apical cell, if included in the section, will be 
 seen to be polygonal in shape. (See Fig. 114, A.) This 
 section will serve well for a study of the different tissues 
 
 FIG. 113. Horizontal 
 
 longitudinal section 
 of the apical bud 
 of Pteris aquilina, 
 showing the apical 
 cell at A in process 
 of dividing. (X 480.) 
 
THE PTERIDOPHYTES. 
 
 191 
 
 that have resulted from the differentiation of the cells of 
 the apical meristem. Starting from the centrally situated 
 ground parenchyma, and passing either 
 to the top or the bottom of the rhizome, 
 make out the following succession of 
 tissues : 
 
 a. A fibro vascular bundle. The row 
 of cells which separates this from the 
 ground parenchyma is known as the 
 bundle sheath. Then come sieve tubes 
 with the surfaces marked by irregular 
 areas of perforations. Next are wide 
 scalariform vessels with distinct mark- 
 ings somewhat resembling the rungs of 
 a ladder. In the center of the bundle 
 are spiral vessels, i.e., vessels with the 
 cell Avail strengthened by a band of cel- 
 lulose running spirally around on the 
 inside. These will not be seen, of 
 course, unless the section passes through 
 the center of the bundle. Outside the 
 spiral vessels the order is reversed, and 
 
 scalariform vessels, sieve 
 tubes, and bundle sheath 
 are again seen. 
 
 b. Next outside the 
 fibrovascular bundle is 
 another region of ground 
 parenchyma. Follow- 
 ing this is a region of 
 the thick-walled cells 
 of the sclerenchyma. 
 Then more ground pa- 
 renchyma, which may happen to include another fibro- 
 vascular bundle. Then come the thick- walled cells of the 
 
 FIG. 114. Vertical 
 longitudinal sec- 
 tion of the apical 
 bud of Pteris aqui- 
 lina, showing the 
 apical cell at A in 
 process of divid- 
 ing. (X480.) 
 
 FIG. 115. a.c., an apical cell of Pteris 
 aquillna seen in vertical transverse sec- 
 tion. The apical bud was on the point 
 of dividing, and a second apical cell is 
 seen at I. (After Sachs.) 
 
192 
 
 PRACTICAL BOTANY. 
 
 hypodermis. Last lies the single row of cells of the epi- 
 dermis. Draw the section and indicate by letters all the 
 tissues you have been able to make out. 
 
 3. Boil an apical bud in Schultze's macerating mixture 
 a few minutes, dissect it with needles, and make a careful 
 study of the scalariform and spiral vessels and sieve tubes 
 
 of the fibrovascular bundles, and 
 of the cells of the sclerenchyma 
 which are thick walled, pitted, 
 and pointed at both ends. 
 
 Treat a portion of an older part 
 of the rhizome with Schultze's 
 macerating mixture, and make 
 similar studies of its tissues. 
 
 The various vessels of the 
 fibrovascular bundles and the 
 elongated cells of the sclerenchy- 
 ma have been built up by the 
 breaking away of the end walls 
 and the fusion of a number of 
 cells into one. The markings on 
 their walls result from strength- 
 ening deposits of cellulose. The 
 spiral and scalariform vessels 
 which occupy the center of each 
 bundle make up the xylem or 
 wood of the bundle. These ves- 
 sels are filled only with air. It 
 is believed that the water containing dissolved nutrient 
 material from the soil finds passage to the upper portions 
 of the plant through the walls of these vessels. The 
 sieve tubes and similar vessels completely encase the 
 xylem ; they are known as the phloem or bark of 
 the bundle. Descending currents of nutrient material 
 elaborated in the leaves find passage in the phloem to 
 
 IV. 
 
 Fia. 116. Cells from the 
 rhizome of Pteris aqui- 
 lina. At the left is seen 
 the pointed end of a sieve 
 tube; B, two sieve tubes, 
 
 5 1 and S 2 , cut lengthwise ; 
 
 5 2 shows the back surface 
 of the tube covered with 
 sieve plates ; the back sur- 
 face of S 1 shows only two 
 small sieve plates, but its 
 side walls, w, w, show sec- 
 tions through sieve plates. 
 (After De Bary.) 
 
THE PTERIDOPHYTES. 
 
 iSITY J 
 V 
 
 
 FIG. 117. Part of a transverse section 
 of the rhizome of Pteris aquilina. 
 A, A, fibro vascular bundles; B, fun- 
 damental parenchyma; C, sclerotic 
 parenchyma or hypodermis. 
 
 all portions of the plant 
 that do not contain chlo- 
 rophyl. The fibro vascular 
 bundles form continuous 
 conduits from the small- 
 est rootlets up through 
 the rhizome and stipe, and 
 send their branches into 
 the divisions and sub- 
 divisions of the leaves. 
 Externally they may be 
 traced as the ribs and 
 veins of the leaves. The 
 possession of the fibro- 
 vascular bundles forms, as already stated, a marked line of 
 separation between the cellular plants of the lower sub- 
 divisions and the vascular plants of the Pteridophytes and 
 the higher Flowering Plants. 
 
 4. Examine under low power a 
 cross section of the rhizome. Draw 
 the section and locate by letters 
 the epidermis, hypodermal tissue, 
 ground parenchyma, sclerenchyma, 
 bundle sheath, scalariform and spiral 
 vessels, and intercellular spaces. 
 
 Treat a section with Schultze's 
 solution. Draw, and locate by let- 
 ters the portions containing lignified 
 cellular tissue. 
 
 Treat a section with iodine solu- 
 tion. What tissues contain starch? 
 These tissues serve as storehouses 
 for the reserve food of the plant. 
 Stain a section, cut after imbedding 
 in celloidin, in picro-carmine for 
 
 FIG. 118. Diagram show- 
 ing the branching and 
 interlacing of the h'bro- 
 vascular bundle in the 
 upper side of the rhi- 
 zome of Pteris aquilina. 
 I shows the origin of a 
 leaf. (After Sachs.) 
 
 CLARK'S BOX. 13 
 
194 
 
 PRACTICAL BOTANY. 
 
 FIG. 119. A leaflet of Pteris aquilina, 
 showing the venation. (After Luers- 
 sen.) 
 
 twenty-four hours ; wash out the carmine and stain with 
 methyl green for fifteen minutes. Wash out excess of 
 green in alcohol, clear in oil of cedar, and mount in Canada 
 
 balsam as a permanent 
 preparation. 
 
 5. Treat pieces of the 
 stipe with Schultze's 
 macerating mixture, 
 dissect, and find and 
 name as many tissues as 
 you can. 
 
 6. Tear off a bit of the epidermis of the under side of 
 the leaf, taking care to secure some from over the veins 
 and some from between the veins. Sketch some of each 
 of the different kinds of cells you find, lettering the 
 sketch to show where each kind of cell is located. Notice 
 the stomata, each inclosed by two guard cells. The sto- 
 mata are the breath- 
 ing pores of the leaf. 
 Affected by variations 
 in moisture and light, 
 the guard cells change 
 their form and open 
 or close the entrance, 
 thus regulating the 
 admission of oxygen 
 and carbon dioxide to 
 some extent, and con- 
 trolling the evapora- 
 tion of the water ac- 
 cording to the neces- 
 sities of the plant. Do 
 you find nuclei in the guard cells? Do you find chloro- 
 phyl bodies in them? Do you find nuclei and chlorophyl 
 bodies in the epidermal cells ? 
 
 FIG. 120. Cells from the under surface of 
 the leaf of Pteris aquilina, showing sto- 
 mata. (X480.) 
 
THE PTERIDOPHYTES. 195 
 
 Examine a piece of the epidermis torn from the upper 
 side of the leaf. Draw a few cells. State how it differs 
 from the epidermis of the lower side. 
 
 7. Hold pieces of the leaf between pieces of pith and 
 cut cross sections. Draw a portion of a section showing 
 a fibro vascular bundle. Beginning on the upper side, 
 notice the epidermis, a single row of cells ; under these, 
 green cells standing perpendicularly to the epidermis, 
 columnar parenchyma; then other similar green cells 
 irregularly arranged and having intercellular spaces be- 
 tween them ; on the lower side of the leaf a single row 
 of cells forming the epidermis. Find sections through 
 
 FIG. 121. A fertile leaflet of Pteris aquilina seen in cross section, sp, spo- 
 rangia ; in, indusium ; ms, mesophyll or loose parenchyma ; mr, midrib ; 
 v, veins. (After Sedgwick and Wilson.) 
 
 stomata in the lower epidermis, and notice that each 
 stoma opens into a large intercellular space, or breath- 
 ing chamber. The chlorophyl-bearing cells of the interior 
 of the leaf are called mesophyll. Do they contain starch? 
 8. Examine the sporangia. These may be obtained by 
 dissecting off the indusium and scraping the sporangia 
 from the margin of the leaf. A sporangium closely re- 
 sembles an interrogation point (?) in shape. Notice the 
 pedicel, or stalk, the annulus of thick-walled cells which 
 extends from the top of the pedicel up one side and over 
 the top of the sporangium, and the thin-walled cells in- 
 closing the body of the sporangium. Draw. When the 
 sporangium is ripe, the thick-walled cells of the annulus 
 become dry and contract; this causes the thin-walled cells 
 
196 
 
 PRACTICAL BOTANY, 
 
 of the opposite side to break apart and scatter out the 
 spores. 
 
 Imbed pieces of a fruiting frond between pieces of pith 
 and cut cross sections. Study the sporangia in situ in 
 these sections. Observe the position of the indusium. 
 
 <st. 
 
 ep. 
 
 FIG. 122. Cross section of the midrib and adjacent parts of a leaflet of Pteris 
 aquilina. The fibrovascular bundle of the midrib is seen in the center, 
 supported above and below by prosenchyma, i.e., cells with greatly thick- 
 ened walls; i.s, intercellular spaces; st, stomata; ep, epidermis. (After 
 Sedgwick and Wilson.) 
 
 Distinguish between the outer indusium formed by the 
 folding over of the edge of the leaf, and the inner or true 
 indusium formed by an extension of the epidermis of the 
 under side of the leaf. Draw. 
 
 If fruiting fronds of Pteris are not easily obtainable, 
 substitute the sporangia of some other Fern ; for example, 
 one of the shield Ferns, 
 
THE PTEBIDOPHYTES. 
 
 197 
 
 9. Examine the spores. What is their shape ? What 
 is the character of their covering ? Crush some of the 
 spores by pressure 011 the cover glass. Treat with 
 Schultze'e solution. Of what is the covering or exospore 
 composed ? Treat another mount of crushed spores with 
 iodine solution. Do they contain starch ? Do you find a 
 nucleus ? 
 
 10. Study the protonemse. These are easily cultivated 
 as follows : Sow the Fern spores on a fresh moist sod 
 placed in the bottom of a glass 
 jar ; also on the moist sides of the 
 jar, and on a sheet of glass to be 
 used as a cover to the jar. As 
 Fern spores usually require a 
 period of rest before they will 
 germinate, use spores of the pre- 
 vious year. Keep this moist 
 chamber under suitable condi- 
 tions of heat and moisture, but 
 not in too strong sunlight. The 
 spores will begin to germinate in 
 about a week, and the progress 
 of the growth may be watched 
 by making examinations at inter- 
 vals of a few days. Draw speci- 
 mens showing successive stages 
 of development. Notice that the growth begins by the 
 bursting of the spore covering. Notice that a rhizoid be- 
 gins to form simultaneously with the first division of the 
 spore contents, and that other rhizoids are formed later. 
 Do the cells of the protonema contain nuclei? Do they 
 contain chromatophores ? Starch ? Find protonemsB that 
 show at the distal end a triangular apical cell resembling 
 the apical cell of the apical bud ; it may not be easy to do 
 this. Notice that the cells of the protonema are at first 
 
 FIG. 123. A sporangium of 
 Pteris serrulata. s, a 
 spore ; c, capsule ; a, an- 
 nulus ; p, pedicel. (After 
 Sumiuski.) 
 
198 
 
 PRACTICAL BOTANY. 
 
 
 FIG. 124. A spore 
 of Pteris serrulata. 
 (After Suminski.) 
 
 arranged to form a linear aggregate ; this arrangement is 
 
 succeeded by a superficial aggregate, and this by a solid 
 aggregate. In passing through these 
 stages the protonema is gradually trans- 
 formed into the prothallium, which is 
 the gametophyte form of the plant. 
 (See Figs. 124, 125, 126, 127, 110.) 
 
 11. If the cultivation of Number 10 
 has not produced prothallia in from six 
 
 to ten weeks, search for them on the Fern pots, the ground, 
 
 and walls of greenhouses where Ferns are cultivated. 
 
 They are very small one eighth to one third of an inch 
 
 in diameter. 
 
 Under low power draw the prothallium as seen from 
 
 above, and again as seen from the under side. Notice the 
 
 distinct heart shape. Does this recall the dichotomous 
 
 division of Liverworts ? Do you find rhizoids ? If so, 
 
 where are they situated ? Why are they not true roots ? 
 
 Under high power examine some of the cells near the 
 
 margin of the prothallium. Do they contain chromato- 
 
 phores ? Nuclei ? Starch ? 
 
 In testing for starch use pro- A 
 
 thallia that have been kept 
 
 in alcohol. 
 
 With the high power search 
 
 the region just below the 
 
 sinus of the heart on the 
 
 under side of the prothallium 
 
 for archegonia. (See Fig. 
 
 110.) They are borne on a 
 
 thickened region of meriste- 
 
 matic tissue called the cushion. 
 
 What is their shape ? Of 
 
 how many cells does each consist ? Can you find the 
 
 canal or opening into the archegonium ? Draw. 
 
 FIG. 125. A, a spore of Pteris 
 serrulata after it has begun to 
 germinate; B, the same, farther 
 advanced ; S, the spore ; r, the. 
 rhizoid ; p, the young protonema. 
 (After Suminski.) 
 
THE PTERIDOPHYTES. 
 
 199 
 
 Search among the rhizoids for spherical antheridia. 
 Draw. It is possible that antherozoids will be found 
 swimming in the water. These are spirally coiled organ- 
 isms, having a number of cilia at the small end ; a spheri- 
 cal body is often seen attached to the larger end. The 
 antherozoids swim to the canal of the archegonium, effect 
 an entrance, and fertilize the egg cell. (See Fig. 110, A 
 and _B.) The egg cell now develops by successive cell 
 
 126 
 
 FIG. 126. The same as Fig. 125, somewhat farther advanced. (After 
 
 Suminski.) 
 FIG. 127. The same as Fig. 126, but the protonema has now developed into a 
 
 young prothallium. A fully developed prothallium is shown in Fig. 110. 
 
 (After Suminski.) 
 
 divisions, and produces a new Fern plant with rhizome, 
 roots, and frond. The new plant remains attached to the 
 prothallium for a time, but finally becomes separated and 
 lives as an independent plant. 
 
 References for Reading. Sedgwick and Wilson's " Biology," pp. 
 105-155; Parker's "Elementary Biology," pp. 344-362; Bidgood's 
 "Elementary Biology," pp. 112-144; Goebel's "Classification of 
 Plants," pp. 189-245; Vines' "Text-Book of Botany," pp. 372-415; 
 Bennett and Murray's " Cryptogamic Botany," pp. 10-95, 119-124; 
 
200 PRACTICAL BOTANY, 
 
 t 
 
 Bower's " Practical Botany," pp. 287-318 ; Huxley and Martin's " Ele- 
 mentary Biology," pp. 443-459 ; Arthur, Barnes, and Coulter's " Plant 
 Dissection," pp. 103-129 ; Dodge's " Practical Biology," pp. 320-335 ; 
 Strasburger and llillhouse's "Practical Botany," pp. 287-297; Car- 
 penter's " The Microscope," pp. 599-605 ; Underwood's " Our Native 
 Ferns and Their Allies " ; Atkinson's " Biology of Ferns " ; Strasburger, 
 Noll, Schenck and Schimper's " Lehrbuch der Botanik," pp. 349-372. 
 
 FIG. 128. Equisetum arvense. 1, a barren plant ; 2, fertile plant ; 3, a spike 
 of sporangiophores of Equisetum arvense ; 4, a single sporangiophore ; 5, a 
 spore with elaters extended ; 6, spore with elaters wrapped around it ; 7, 
 a fertile plant of Equisetum sylvaticum; 8, a prothallium of Equisetum. 
 (After Kerner and Oliver.) 
 
 CLASS II. The Horsetails (ISquisetince). There is now 
 only one order in this class, and this is homosporous. 
 
THE PTERIDOPHYTES. 
 
 201 
 
 In the carboniferous age of the world's history there 
 were many genera, as is evidenced by the remains found 
 in the coal formations, and among these heterosporous 
 forms are known to have 
 existed. 
 
 The stem of Equisetum 
 is subterranean. From 
 it hollow vertical shoots 
 rise ; some sterile, bearing 
 only leaves and branches ; 
 others bearing sporangia, 
 which are located on 
 the inner sides of scales 
 grouped together into 
 cone-shaped tips of the 
 shoots. The ripe spore 
 cases open on the inner 
 side. The spores are 
 greenish in color ; each 
 has four threads, or ela- 
 ters, with knob-shaped 
 ends, which are wound 
 round the spore when 
 moist, but are extended 
 when dry ; in other words 
 they are hygrometric. 
 These threads undoubt- 
 edly help in the trans- 
 portation of the spore. These spores are of great interest 
 under the microscope. The moisture of the breath upon 
 them when dry causes the elaters to fold up. When the 
 moisture evaporates, they again extend themselves. 
 
 The cylindrical shoots are hollow, the woody tissues 
 being arranged in a single circle of fibrovascular bundles. 
 The epidermis contains silica to such an extent that it 
 
 FIG. 129. Equisetum sylvaticum. In 
 the center is a barren branch. On 
 the right and left are fertile branches. 
 (After Bennett and Murray.) 
 
202 PRACTICAL BOTANY. 
 
 may be boiled for some time in strong nitric acid without 
 losing its shape. All the organic matter is thus removed, 
 
 and the skeleton of the 
 stem remains in pure 
 silica a most beauti- 
 ful object when seen 
 under polarized light. 
 It not only shows the 
 
 FIG. 130. A, a spore of Equisetum with 
 
 the elaters closely wrapped about it ; B, general Structure OI 
 the same with elaters extended. (After t ^ e epidermis, but pre- 
 Carpenter.) r . 
 
 serves the stomata with 
 
 their guard cells. The small leaves are arranged in whorls, 
 and, in the branching species, the branches are in whorls. 
 
 References for Reading. Goebel's " Classification of Plants," pp. 
 256-273 ; Parker's " Elementary Biology," pp. 366-368 ; Vines' " Text- 
 Book of Botany," pp. 416-420; Bennett and Murray's " Cryptogamic 
 Botany," pp. 100-113, 124-130 ; Bower's " Practical Botany," pp. 325- 
 340. 
 
 CLASS III. The Club Mosses (Lycopodince). These 
 are principally perennial plants with creeping stems. 
 Some are homosporous, others are heterosporous. Some 
 of them resemble in the character of their leaves different 
 species of Conifers so closely that they have the common 
 names of Ground Pine, Running Pine, Ground Cedar, 
 and Ground Fir. The resemblance is still further car- 
 ried out in the conelike spikes that some species bear on 
 upright branches. These spikes are made up of scalelike 
 leaves, each bearing on the inner side near the base a 
 somewhat kidney-shaped spore case which, when ripe, 
 opens transversely near the upper part and discharges 
 quantities of fine sulphur-colored spores, all of one kind. 
 The first stage of the development of the Club Mosses 
 from the spores is little understood, as the prothallia have 
 been seen and studied in only a few species. The spores 
 contain a large amount of oil, so that they are very in- 
 
THE PTER1DOPHYTES. 203 
 
 flammable. They have been extensively used, under the 
 name of lycopodium powder, to produce flash lights. 
 
 There are about 100 species of the larger Club Mosses 
 in all the world, the greater number growing in the 
 tropics. About eleven species grow within the limits 
 of the United States, the most common ones with us 
 being Lycopodium dendroideum, or Ground Pine, L. clava- 
 
 Fio. 131. Transverse section of stem of Lycopodium complanatum. E, E. 
 E, cortex; N, sclerenchyma; I, fibrovascular bundle sheath; S, phloem 
 portion; 0, xylem portion of the central fibrovascular bundle. (X 60.) 
 
 turn, or Running Pine, and L. complanatum, sometimes 
 spoken of as Ground Fir or Ground Cedar. 
 
 The plants of this order, while somewhat resembling 
 the Mosses in outward appearance, differ from them in the 
 character of their fructification and in their higher organi- 
 zation. The stems show centrally situated, well-defined 
 fibrovascular bundles which may be traced into the 
 
204 PRACTICAL BOTANY. 
 
 leaves. In these two particulars they clearly resemble the 
 Ferns with which they are classed as allies. The name of 
 the order is from two Greek words meaning wolf foot, 
 though the reason is not apparent why this name should 
 be given to these plants. It was possibly suggested by 
 the short hairy branches of Lycopodium clavatum. 
 
 The Lycopodinse include the Little Club Mosses (Sela- 
 ginelleoe), which number about 335 species, mostly tropi- 
 cal ; seven are native to the United States. Many of the 
 tropical species are cultivated in greenhouses for their 
 delicate and beautiful foliage. In outward appearance 
 the Little Club Mosses resemble the Club Mosses, except 
 that they are much smaller. The characteristic that 
 distinguishes them is the production of two kinds of 
 spores, macrospores, usually four in number, and micro- 
 spores, of indefinite number. 1 
 
 Here also are included the Isoeteoe, or the Quillworts. 
 The scientific name is from two Greek words meaning 
 equal and year ; it is appropriate, as these plants remain 
 the same throughout the whole year. The common name 
 is also appropriate because of the resemblance of the 
 leaves to quills. There are about 50 species in the 
 order ; 16 occur in the United States. Five of these 16 
 species grow submerged in water ; five grow in places 
 where they are wholly out of water in the dry season ; 
 the others grow partly in and partly out of water. The 
 leaves grow in bunches from a sort of bulb, varying in 
 number from 10 to 100, and in length from 2 to 20 inches. 
 
 References for Reading. Goebel's " Classification of Plants," pp. 
 274-297 ; Parker's " Elementary Biology," pp. 371-373 ; Vines' " Text- 
 Book of Botany," pp. 421-430 ; Bennett and Murray's " Cryptogarnic 
 Botany," pp. 38-63, 115-119; Bower's "Practical Botany," pp. 261- 
 286. 
 
 1 If time permits, arrange Practical Studies on the Horsetails, Club 
 Mosses, and Little Club Mosses. 
 
VIII. 
 
 THE SPERMAPHYTES. 
 
 The eighth subdivision includes the higher and so- 
 called Flowering Plants. They vary in size from plants 
 a small fraction of an inch in height up to the mightiest 
 trees. They are, in general, plants of a highly differen- 
 tiated and complex structure. The plant is the sporo- 
 phyte. There are two kinds of spores, microspores or 
 pollen grains, and macrospores borne in embryo sacs. 
 The contents of the pollen grain develop by cell division- 
 into a minute prothallium which takes the form of a tube 
 projecting from the pollen cell. The contents of the 
 embryo sac also develop into a minute prothallium. 
 These prothallia represent the gametophyte. The first 
 step in the reproduction is the extension of the pollen 
 tube, which is an outgrowth of the inner coating of the 
 pollen grains, into the embryo sac, contact with the viscid 
 secretion of the stigma being a necessary prerequisite to 
 the growth of the pollen tube. As the pollen grains are 
 not self -motile, nature provides for their transportation 
 from the anther to the stigma, by means of the wind, by 
 the adaptation of the various parts of the flowers to this 
 end, and by rendering the flowers attractive to various 
 insects, either because of the nectar which furnishes food 
 for the insects or because of their colors which attract or 
 serve as a means for concealment or protection for them. 
 These little creatures carry the pollen from anther to 
 stigma on the same or on different flowers. 
 
 The feature that especially distinguishes the Sperma- 
 phytes from the plants of the seven preceding subdivi- 
 
 205 
 
206 
 
 PRACTICAL BOTANY. 
 
 sions is the production of true seeds, which are the result 
 of the fertilization of the embryo cell by the receipt of 
 the contents of the pollen cell. The embryo cell is borne 
 in a pistil, and the pistil or pistils of a flower are known 
 as the gyncecium ; the stamens with their pollen-bearing 
 anthers constitute the androecium. According as the 
 embryo cells or ovules are exposed to the direct action of 
 the pollen grains, or are borne in closed ovaries, the Sper- 
 maphytes are divided into two classes : 
 
 CLASS I. THE GYMNOSPERMS. 
 CLASS II. THE ANGIOSPERMS. 
 
 CLASS I. The Gymnosperms. In these the ovules are 
 borne on the lower part of the inner surface of modified 
 leaves which form a cone or female 
 flower ; the pollen is also borne on 
 modified leaves forming a small cone 
 or male flower. At the season of fer- 
 tilization the ovules are exposed to 
 the air, the pollen falls directly upon 
 them, and they are fertilized by the 
 passing of the contents of the pollen 
 grains into the ovules through tubes 
 which develop from the inner coat of 
 the pollen grains. The leaves of the 
 cone then close, remain closed during 
 the development, and open at matu- 
 rity to discharge the seed. The Gym- 
 nosperms include the Cycads, which 
 are native in hot climates ; the Coni- 
 fers, which include the Pines and re- 
 lated trees and which are native in 
 temperate and cold climates ; and the 
 Joint Firs, which are native in hot 
 climates. 
 
 y 
 
 r 
 
 FIG. 132. A , apollen grain 
 of the Gymnosperm, 
 Ceratozamia longi- 
 folia, on the point of 
 beginning to develop ; 
 B, the same after the 
 tuhe has partially de- 
 veloped. (After Ju- 
 ranyi.) 
 
THE SPERMAPHYTES. 
 
 207 
 
 THE PINES. PRACTICAL STUDIES. 
 
 1. Examine any Pine tree as it grows. Is the stem 
 excurrent, i.e., does it rise as a central main shaft, or is 
 it deliquescent, i.e., does it divide 
 and subdivide into branches ? Are 
 the branches arranged in any par- 
 ticular way on the stem? If so, 
 state what the arrangement is. 
 Examine the apical bud at the end 
 of each branch ; also around its base 
 several lateral buds. The apical 
 bud develops into the shoot of the 
 next season ; the lateral buds de- 
 velop into the new branches. Start- 
 ing with the top of a young Pine, 
 can you tell how much is this sea- 
 son's growth? Can you trace the 
 growth of the different years down 
 the stem ? Cut across the stem 
 where it is at least half an inch in 
 diameter. Count the . number of 
 rings of annual growth. How does this number com- 
 pare with the age as determined by tracing the growth 
 of the different years down the stem ? Notice the color 
 of the bark. Is the bark on the stem and also on the 
 branches smooth or rough? Observe the scale leaves on 
 the branches. Notice that the foliage leaves are produced 
 on short dwarf branches. Describe the surface of the 
 dwarf branches. How many leaves grow on a branch ? 
 Notice the sheath at the base of the leaves. Examine 
 different Pine trees. Is the number of leaves on a dwarf 
 branch the same in the different species? Identify the 
 species studied by consulting Gray's "Manual." 
 
 FIG. 133. Longitudinal sec- 
 tion of the nucellus of 
 the naked ovule of the 
 Gymnosperm, Juniperus 
 Virginiana. p is a pol- 
 len grain which is send- 
 ing its tube down into 
 the ovule. (After Stras- 
 burger.) 
 
208 PRACTICAL BOTANY. 
 
 2. Dig up some very young Pines those of the 
 present season's production, for instance. Is there a 
 central taproot, or is the main root lost by division into 
 branches ? Compare with the root of a tree three or four 
 years old. Describe the mode of branching. Notice and 
 describe the rootlets. Draw enough to give a good idea 
 of the gross morphology of the root. 
 
 3. Study the male flowers. These are to be obtained 
 only in the spring. They mature in May or June. Alco- 
 holic material may be used for the observations. The 
 male flowers may be obtained from various species, but 
 are most surely to be found on the Scotch Pine, the 
 Austrian Pine, and the Red or Norway Pine, descriptions 
 of which are given in various botanies. The male flowers 
 are borne as small yellow cones at the base of the shoot 
 of the new season's growth. Are these cones sessile, or 
 are they borne on stalks? Draw "an entire cone. Is 
 there any definite arrangement of the modified leaves 
 which compose the cone ? Are these leaves, the sta- 
 mens, sessile or borne on stalks? Remove some of the 
 stamens and examine them for the pollen, sacs. On which 
 surface of the stamens, and where on the surface, are the 
 pollen sacs borne ? What is the shape of the pollen sacs ? 
 Find mature specimens. How do the pollen sacs open? 
 Draw, showing an entire stamen. Examine under high 
 power some of the pollen grains. Draw. Apply re- 
 agents, if necessary, and determine whether there is a 
 nucleus and nucleolus. Is starch present ? Is oil present ? 
 If starch and oil are present, are they evenly distributed 
 in all parts of the grain? Make out two coats in the cell 
 wall. Prove that the outer is composed of lignified cel- 
 lulose and the inner of normal cellulose. When the 
 pollen grain develops in contact with the ovule, the inner 
 coat grows into the tube which penetrates the micropyle 
 of the ovule. 
 
THE SPERMAPHYTES. 209 
 
 4. Study the female flowers. These are borne near the 
 very tip of the new shoot as pinkish-green cones. They 
 are to be gathered in June. Are these cones sessile, or 
 borne on stalks ? Draw a cone. Dissect a cone. Notice 
 that the modified leaves are of two kinds. The thin and 
 small scale leaf or bract corresponds to an ordinary leaf ; 
 the thicker scale or carpel bears ovules. Draw a bract. 
 Where on the carpel are the ovules situated ? Draw a 
 carpel, showing the ovules. The ridgelike projection of 
 the carpel is called the keel; its function is to guide the 
 pollen grains towards the ovules. 
 
 5. Study the development of the ovule into the seed. 
 Two years are required for this. Branches of Scotch, 
 Austrian, or Red Pine may be found in the early part of 
 the summer bearing the cones at three stages of develop- 
 ment : a. The female flowers, already studied, at the apex 
 of the new shoot, b. Cones one year old at the apex of 
 the shoot of the preceding year. c. Cones in the second 
 year of their growth at the apex of the two-years-old 
 shoot. 
 
 What is the position of the ovules on the carpels of the 
 youngest cone ? Find on each ovule the micropyle a 
 small opening into the interior through which the pollen 
 tube enters. Where on the ovule is it situated ? Make a 
 section of an ovule through the micropyle ; with a hand 
 magnifier or low power distinguish the integument or 
 outer coat ; next within the integument is the nucellua, 
 composed of parenchyma ; near the end of this mass of 
 parenchyma farthest away from the micropyle is situated 
 the embryo sac, which is a large cell containing more or 
 less of a very soft tissue the endosperm. Draw. 
 
 Dissect a year-old cone. Make a section of a seed 
 through the micropyle. Compare the micropyle, integu- 
 ment, embryo sac, and its contents with the same parts in 
 the youngest cone. Draw. 
 CLARK'S EOT. 14 
 
210 PRACTICAL BOTANY. 
 
 Obtain the ripe or nearly ripe seeds from a two-years- 
 old cone. Notice the wings and the markings on the sur- 
 face of the seed. Of what use are the wings? Make a 
 section of a seed through the micropyle, and compare with 
 the observations made on the first and second year cones. 
 The integument has thickened greatly, and now consists 
 of two coats ; the nucellus has almost disappeared ; the 
 endosperm has increased in amount and firmness because 
 of the accumulated food supply for the new plant. 
 Macerate the endosperm in caustic potash and dissect it 
 with needles. Make out the embryo, and in it a number 
 of cotyledons and a radicle. 
 
 6. Make thin longitudinal sections of an apical bud 
 that is, the winter bud from which the next year's new 
 shoot will develop which has been preserved in alcohol. 
 Mount in Schultze's solution all of the sections that are 
 cut through or nearly through the apex. Examine under 
 both low and high powers. Notice the thin- walled cells, 
 abundantly supplied with protoplasm, at the apex. In the 
 acrogenously growing plants of the lower subdivisions up 
 to the Lycopods, the growth in length originates in the 
 division of an apical cell. In the Phanerogams the thin- 
 walled cells near the apex of the stem are capable of divi- 
 sion. From their division arises the growth of the plant 
 in length. The apex of the stem is, therefore, called the 
 growing apex or the punctum vegetationis. The newly 
 formed tissue at and near the apex is the primary meristem. 
 Trace the differentiation of these cells as far back as your 
 section permits. Do you find tracheides and spiral ves- 
 sels? 
 
 7. Study the foliage leaves. Measure a number of 
 leaves on each of two or three species of Pine. State 
 the average length for each species examined. What is 
 the shape of the end ? Notice rows of dots, the stomata, 
 running lengthwise the leaves. With a sharp razor cut 
 
THE SPERMAPHYTES. 
 
 211 
 
 off a thin slice of the epidermis, mount in water, and ex- 
 amine the stomata under high power. Run the finger 
 over the edges of the leaves. What is noted ? Cut cross 
 sections of the leaves of different species. What is the 
 shape of the cross section in each case ? Examine with a 
 magnifying glass and draw, showing all you see. Measure 
 or estimate the greatest diameter of the leaves. 
 
 Study Fig. 134, which is a picture of a thin cross section 
 of the leaf of the Red Pine, Pinus resinosa, or Norway 
 Pine. Around the out- 
 side is a single layer of 
 cells with thick walls, A, 
 the epidermis. This cov- 
 ering of thickened tissue 
 protects the softer in- 
 terior of the leaf. At the 
 corners, B and B, are 
 large cells whose irregu- 
 larity causes the rough- 
 ness of the edges. Just 
 within the epidermis is 
 another narrow band of 
 thick-walled cells, the 
 hypoderma, O. Within this is a broad band of delicate 
 parenchyma with folded cell walls, D. This is the 
 mesophyll. When the leaf was living these cells were 
 filled with protoplasm bearing green chlorophyl bodies. 
 Situated in the mesophyll are five large resin ducts, E, 
 each surrounded by a row of glandular cells which 
 secreted the resin. Next within is an elliptical ring of 
 oval cells, F, the endodermis, or bundle sheath. The 
 bundle sheath incloses thin-walled parenchyma, 6r, which 
 did not contain chlorophyl, and two fibrovascular bundles. 
 Each fibrovascular bundle consists of two parts. The 
 woody part or xylem is situated towards the flat or upper 
 
 FIG. 134. Leaf of Red Pine, Pinus resi- 
 nosa. Transverse section. A, epi- 
 dermis; B, B, enlarged corner cells; 
 C, hypoderma ; D, mesophyll ; E, resin 
 ducts ; F, bundle sheath ; G, colorless 
 parenchyma. 
 
212 PRACTICAL BOTANY. 
 
 side of the leaf. The bark portion, or phloem, is situated 
 towards the lower or outer, rounded side of the leaf. 
 
 Mount in Schultze's solution thin cross sections of 
 leaves of different species of Pine, cut after imbedding in 
 paraffin or celloidin. 1 Comparing with Fig. 134, locate on 
 a drawing of the section all the parts mentioned above. 
 The whole section should be drawn in outline, but it will 
 be sufficient if the details are drawn in only half of it. 
 In what portions of the section is the cellulose lignified? 
 Notice under high power that the epidermis is composed 
 of three layers : the cuticle is the outer, thin and trans- 
 parent coating ; the other two coatings are thick walled. 
 Can you make out cracks running from the centers of the 
 cells outward through these walls? Find places where 
 the section passes through a stoma; observe the guard 
 cells, and the air chamber into which the stoma opens. 
 
 Trace the hypoderma around the section. Is the num- 
 ber of rows of cells of which it is composed constant? 
 How many rows do you find? Observe the hypoderma 
 beneath a stoma ; what do you notice ? 
 
 Tie a number of fresh leaves together with thread 
 tightly. Imbed the bundle in pith and cut cross sections. 
 Mount in water and examine the mesophyll. Observe 
 the abundant chlorophyl. Determine if it bears starch. 
 Notice the folded walls of the cells. 
 
 Observe the thin- walled parenchyma within the bundle 
 sheath. Does it bear chlorophyl and starch? What is 
 the prevailing shape of the cells as seen in cross section ? 
 
 Draw under high power the xylem and phloem as seen 
 in the section which was mounted in Schultze's solution. 
 Also draw a portion of the bundle sheath. What do you 
 find to be the contents of the cells of the bundle sheath in 
 a section from a fresh leaf ? 
 
 1 For methods of preparation, see the author's "Practical Methods 
 in Microscopy," Chap. VII. 
 
THE SPERMAPHYTES. 
 
 213 
 
 8. Study Fig. 135, which is a cross section of the stem 
 of the White Pine, Pinus strobus, cut in July of the second 
 year of its growth. On the upper side of the picture is 
 the epidermis, J., which is smooth in the young branches, 
 but becomes covered, at a later period, with brown scales 
 that result from the dying of the earlier bark. Within 
 the epidermis is a broad band, E, which includes two 
 or three rows of rectangular (as seen in section) cells of 
 the cork la} r er, B ; 
 the cortical paren- 
 chyma, <?, which 
 makes up the 
 greater part of the 
 band ; and resin 
 ducts, jP, each sur- 
 rounded by layers 
 of epithelial or 
 glandular cells 
 whose function is 
 to secrete the resin 
 or pitch. On the 
 inner side, the cells 
 of the cortical layer 
 pass into the cells 
 of the irregular 
 layer, D, the true 
 
 phloem. Again there is a gradual transition to the cells 
 of the cambium layer, Gr. All the tissues thus far men- 
 tioned up to and including the outer part of the cambium 
 layer make up the bark. Inside the cambium is a broad 
 layer, H, of the new wood formed during the second year's 
 growth ; inside of that is another broad layer, /, of wood 
 that was formed by the growth of the first year. The 
 two layers, H and J, and the inner part of the cambium 
 layer, constitute the xylem or wood. In the layer, Z are 
 
 FIG. 135. White Pine, Pinus strobus. Trans- 
 verse section of a stem in the second year of 
 growth. A, epidermis; B, cork layer; C, cor- 
 tical parenchyma ; Z>, phloem ; F, resin ducts; 
 G, cambium layer ; H, wood in process of for- 
 mation in the second year; /, wood formed 
 during the first year. (X 35.) 
 
214 PRACTICAL BOTANY. 
 
 several small resin ducts. The narrow dark lines running 
 in the radial direction through the xylem, and even ex- 
 tending out through the cambium layer into the phloem, 
 are the beginnings of medullary rays. In the central part 
 of the stem is the pith parenchyma, K. The projections 
 of the pith parenchyma into the xylem are the places of 
 origin of branches which developed just above the plane 
 of this section. 
 
 Cut transverse sections of a second year stem that has 
 lain in alcohol to dissolve out the pitch arid has afterward 
 been softened by soaking in equal parts of alcohol and 
 glycerine for twenty-four hours. Do not try to get com- 
 plete sections, but get thin cuttings, showing all the parts 
 from the epidermis to the pith. Mount in Schultze's solu- 
 tion, and identify under low power all the above-mentioned 
 parts. Draw enough of the section to locate everything 
 observed. 
 
 Cut similar transverse sections of first year shoots. 
 Compare with the preceding section. Draw a portion as 
 before. Cut similar sections of a piece of the stem that 
 is four or five years old. Compare with the other two, 
 drawing a portion as before. 
 
 Under high power examine the cambium layer in a 
 delicate section. In this layer the growth of the stem in 
 thickness originates. Find in this layer cells with very 
 thin walls. Draw a few. What is their shape ? During 
 the period of growth the cells undergo rapid fission in the 
 tangential direction : the outer halves developing into 
 the various tissues of the bark ; the inner halves into 
 the wood. From this layer follow out into the phloem. 
 What changes do the cells undergo as they increase in 
 age ? Are the changes abrupt or gradual ? Starting 
 again with the thinnest cells of the cambium layer, 
 trace the development of the cells into the xylem, stating 
 what you observe. Compare with the changes on the 
 
THE SPERMAPHYTES. 215 
 
 outer side of the cambium layer. Which are the more 
 abrupt ? 
 
 Examine the cells of the cortical parenchyma. What is 
 their prevailing shape ? Do you find intercellular spaces ? 
 
 Consider the resin ducts. The study of the develop- 
 ment of young shoots shows that the resin ducts are inter- 
 cellular spaces which have arisen by the gradual drawing 
 apart of the cells to make room for the resin as it is se- 
 creted. Examine the cells of the two inner rows of glan- 
 dular cells next to the duct. In these cells the resin was 
 secreted. What is the shape of these cells ? Examine 
 the rows of cells next outside. In these cells starch was 
 stored up to be changed into resin by the action of the 
 cells of the two inner rows. Draw a resin duct with its 
 glandular cells under suitable power. 
 
 Examine the cells of the cork layer. What is their 
 shape ? Draw a few. In this layer, cell division goes on 
 to a limited extent. 
 
 Study the xylem under high power. The cells here 
 seen in cross section are known as trache'ides of the wood. 
 Draw a few. Find places where three separate layers 
 may be made out in the cell wall. Draw. Find on the 
 radial walls places where the layers have separated and 
 present somewhat the appearance of a double-convex lens 
 seen in section. These are sections through bordered pits. 
 
 Trace a medullary ray from the pith parenchyma out 
 into the cortical parenchyma. Those that can be so traced 
 were the first to originate, and are called primary medul- 
 lary rays. There are others that extend only part way 
 from the pith to the cortex ; these formed later and are 
 called secondary medullary rays. The medullary rays 
 originate in the crowding together of the older cells by 
 the rapidly forming new cells of the cambium. 
 
 Examine a resin duct in the xylem and compare its 
 structure with the resin ducts of the cortex. Draw. 
 
216 PRACTICAL BOTANY. 
 
 These resin ducts are connected with the cortical resin 
 ducts by channels through the medullary rays. 
 
 Using a piece of fresh green stem, cut thin cross sec- 
 tions and examine them for cell contents. Where is 
 chlorophyl found ? Determine in what parts of the sec- 
 tion starch is present; examine particularly the cells of 
 the cortical parenchyma, those surrounding the resin ducts, 
 and the phloem. Try to find crystals in the cells in the 
 phloem region. Look for resin ; it may be tested for by 
 tincture of alkanna. If the section is taken in the rapidly 
 growing season, examine the cells of the cambium layer 
 for cell contents and nuclei. State in what condition you 
 find the cells of the xylem. 
 
 9. Cut thin radial sections of the stem. Do not try to 
 get large sections ; a narrow slice from the epidermis to 
 the pith will show every point of the structure. Mount 
 in Schultze's solution. Draw and locate all the parts 
 pointed out in Fig. 135. 
 
 Under the high power study the cambium layer, start- 
 ing with the narrowest cells and examining all in succes- 
 sion out towards the phloem. What is the shape of the 
 cells? Are the end partitions easily seen? Is the proto- 
 plasm abundant or scanty ? Do you find a nucleus ? 
 
 Describe the cells of the phloem. Find long cells with 
 irregularly circular patches of sieve plates on their sides ; 
 these are sieve tubes. Draw. Can you find crystals in 
 any of the cells of the phloem ? 
 
 Examine the cells of the cortical parenchyma. What 
 is their shape as seen in the radial section? Find resin 
 ducts. It may be necessary to examine several sections, 
 as all may not have passed through a resin duct. Draw 
 some of the glandular cells with a few of the adjacent 
 cells of the cortical parenchyma. Draw also a few of the 
 cells of the cork layer and epidermis. Starting again with 
 the narrowest cells of the cambium, compare the transition 
 
THE SPERMAPHYTES. 
 
 217 
 
 to the x}4em cells with the transition to the phloem cells. 
 Which is the more abrupt ? 
 
 Study the cells of the xylem. They are called trache- 
 ides. What is their shape? Note the discoid markings 
 on their walls. These are the bordered pits ; recall their 
 appearance as seen in the transverse section. Do you find 
 any cell contents in the trache'ides? Notice the medul- 
 lary rays which 
 run horizontally 
 across the tra- 
 cheides. Can 
 you trace them 
 through the 
 cambium into 
 the phloem? 
 Count the num- 
 ber of cells in 
 height. Is the 
 number con- 
 stant in a given 
 specimen ? Ex- 
 amine radial sec- 
 tions of differ- 
 ent species of 
 Pine. Is the 
 number of cells 
 in the height of 
 the medullary rays the same in different species ? Follow 
 across the tracheides from the inner side of one of the 
 annual layers into the next outside layer. What changes 
 do you notice in the size and character of the tracheides ? 
 Account for the difference. Do you find resin ducts in 
 the xylem ? On the border between the tracheides and 
 the pith parenchyma, find tracheides with spiral or annu- 
 lar markings. Draw. Do you also find some that have 
 
 FIG. 136. Radial section of Georgia Hard Pine, 
 showing two of the annual layers. A is the bound- 
 ary between the growth of the two years; B, B 
 are medullary rays ; C, C, pitted ducts. (X 35.) 
 
218 PRACTICAL BOTANY. 
 
 both the bordered pits and the spiral markings ? If so, 
 draw. 
 
 Draw a few cells of the pith. Do you find more than 
 one kind of cell ? Do you find markings of any kind on 
 the cell walls ? Do you find any cell contents ? 
 
 10. Cut tangential sections and look for the medullary 
 rays, which will, of course, be seen in cross section. These 
 cross sections have the shape of a double convex lens seen 
 in section. Draw two or three of the rays, representing 
 accurately the number of cells, and fill in the tracheiides 
 between. 
 
 References for Reading. Goebel's " Classification of Plants," pp. 
 299-346; Vines' "Text-Book of Botany," pp. 431-489; Parker's 
 " Elementary Biology," pp. 373-384 ; Strasburger and Hillhouse's 
 "Practical Botany," pp. 298-310 f; Bessey's " Essentials of Botany," 
 pp. 212-225 ; Bower's " Practical Botany," pp. 229-260 ; Arthur, Barnes, 
 and Coulter's " Plant Dissection," pp. 130-171 ; Boyer's " Elementary 
 Biology," pp. 147-154 ; Scott's " Structural Botany," pp. 231-281. 
 
 CLASS II. The Angiosperms. The Angiosperms are 
 distinguished from the Gymnosperms by the manner in 
 which the pollen cells and the embryo cells are borne. 
 The ovules are borne in closed cavities, the ovaries, at 
 the base of pistils, which are modified leaves ; the pollen 
 cells are borne in anthers raised on stamens, which are 
 also modified leaves ; both pistils and stamens may be 
 borne in the same flower, i.e., the plant may be monoe- 
 cious, or they may be borne in separate flowers, i.e., the 
 plant may be dioecious ; surrounding the stamens and 
 pistils are other modified leaves forming the floral en- 
 velope, which, in normal cases, is composed of an inner 
 circle, the corolla, usually of delicate and more or less 
 bright-colored leaves, the petals, and an outer circle, the 
 calyx, usually of green leaves, the sepals. 
 
 The ripened pollen grains fall by their own weight, are 
 blown by the wind, are jerked by mechanical arrange- 
 
THE SPERMAPHYTES. 
 
 219 
 
 FIG. 137. a, a pollen grain of the Angiosperm, Allitnn Jistulosum ; b and c 
 show two stages of the development of the tube ; d and e show two stages 
 in the development of the pollen grain of Monotropa hypopitys ; f, a num- 
 ber of pollen grains of Platanthera bifolia in process of division ; g, pollen 
 grain of Orchis mascula forming its tube. (After Strasburger.) 
 
 ments worked by nature, are carried by 
 or in some similar manner are brought 
 of the same or of different flowers in 
 contact with the viscid fluid secreted by 
 the stigma, which forms the tip of the 
 pistil. Excited into activity by this 
 fluid, .the pollen grain bursts its outer 
 coat and expands its inner coat into a 
 tube which grows down through the 
 stigma and style until it comes in con- 
 tact with the ovule, enters the micro- 
 pyle of the ovule, and finds the embryo 
 sac. The contents of the pollen grain 
 now mingle with those of the embryo 
 sac, and the life of a seed commences. 
 (See Figs. 137 and 138.) 
 
 The matured seed incloses an embryo 
 and more or less stored-up material, the 
 endosperm, to nourish the embryo when 
 it germinates. The relative proportions 
 of embryo and endosperm vary greatly 
 
 insects or birds, 
 from the anthers 
 
 FIG. 138. Longitudi- 
 nal section of an 
 ovary of an An- 
 giosperm. , the 
 stigma ; b, pollen 
 grains ; c, a pollen 
 tube passing down 
 to the egg cell, se. 
 (After Thome and 
 Bennett.) 
 
220 PRACTICAL BOTANY. 
 
 in different seeds. The embryo may be large and the 
 endosperm small, or the endosperm large and the embryo 
 small ; in some cases the endosperm is entirely wanting. 
 The embryo is a rudimentary plant/ When this rudi- 
 mentary plant begins to grow, it sends its roots down into 
 the soil and its leaves up into the air. Some plants de- 
 velop their leaves alternately; others develop them in 
 pairs. From these facts has arisen a division of the 
 Angiosperms into: 
 
 SUBCLASS I. THE MONOCOTYLEDONS. 
 SUBCLASS II. THE DICOTYLEDONS. 
 
 SUBCLASS I. The Monocotyledons. In the Monocoty- 
 ledons there is only one cotyledon in the embryo. The 
 
 leaves which are 
 usually parallel- 
 veined develop 
 alternately. In 
 the stems the 
 wood is never 
 arranged in cir- 
 cles, but is 
 placed in bun- 
 dles that are 
 scattered irreg- 
 ularly through 
 the entire thick- 
 ness of the stem ; 
 in the more 
 woody stems 
 
 FIG. 139. Transverse section of Sugar Cane. ,, 
 
 the bundles are 
 
 most abundant near the circumference, forming by the 
 interlacing ends of the fibers that compose them a tough 
 rind or false bark to cover the stem. The parts of the 
 flower are usually in threes ; never in fives. The flowers 
 
THE SPERMAPHYTES. 
 
 221 
 
 range from the inconspicuous, unattractive forms borne 
 by the grasses to the conspicuous and beautiful ones pro- 
 duced by the orchids. 
 
 There are about 18,000 species of Monocotyledons; these 
 are variously arranged in groups, series, and orders by 
 different botanists. The Monocotyledons include some of 
 the most important economic and some of the most beauti- 
 ful ornamental plants. Our present limits will permit of 
 the study of but a single type. 
 
 INDIAN CORN. PRACTICAL STUDIES. 
 
 1. Examine an entire plant of 
 when it is in the flower. The 
 male flowers are borne in two- 
 flowered spikelets in spikes at the 
 top of the stem, constituting what 
 is called the tassel. The female 
 flowers are borne in dense spikes 
 of many rows on short branches 
 that grow in the axils of the 
 leaves. Each filament of the silk 
 is an elongated style. The pollen 
 grains, falling or blown from the 
 male flowers, extend their tubes 
 through these long styles, fertilize 
 the contents of the embryo sac at 
 the base of the pistil, and kernels of 
 Corn develop. Examine the leaves 
 for their arrangement and vena- 
 tion. Does the plant send down 
 a single taproot, or does it lose it- 
 self in branches ? Where do the 
 secondary roots originate? Are 
 there roots of a still higher order ? 
 
 Indian Corn, Zea mays, 
 
 FIG. 140. Longitudinal sec- 
 tion of fruit of Zea mays, 
 a, rind of the fruit ; n, ap- 
 pendage of the stigma ; fs, 
 base of the fruit; eg, yel- 
 lowish, firm part of the 
 endosperm ; ew, its white 
 and looser part ; sc, the 
 scutellum of the embryo ; 
 ss, its tip; e, its epithe- 
 lium; k, the plumule; w 
 (below) , the primary root ; 
 ws, rootsheath ; w (above), 
 secondary roots springing 
 from the first internode of 
 the primary stem, st. Mag- 
 - nified. (After Goebel.) 
 
222 
 
 PRACTICAL BOTANY. 
 
 2. Cut through seeds of Corn in a median plane longi- 
 tudinally at right angles to the broad sides. Notice the 
 thick double-walled coating. This consists of the pericarp 
 or wall of the ovary and the seed coat or developed integu- 
 ment of the ovule. The remains of the style will be found 
 at the apex of the smaller end of the seed. At one side, 
 near the smaller end of the seed, is the embryo. The 
 embryo is separated from the endosperm by the scutellum, 
 
 which is an ar- 
 rangement for 
 the absorption 
 of the food for 
 the nourishment 
 of the embryo. 
 The endosperm 
 consists of two 
 parts a firm 
 yellow part on 
 the side of the 
 seed opposite the 
 embryo, and a 
 less firm white 
 part .occupying 
 
 ^ e central DOr- 
 
 1 1 o n and the 
 larger end. Draw, showing all you have seen. Scrape 
 off some of the endosperm and mount in water. Deter- 
 mine if starch is present. If it is, draw some of the 
 grains. Dissect the embryos from seeds of corn that have 
 been softened by soaking. Make out the apical bud, or 
 plumule, pointed towards the large end of the seed, the 
 caulicle, or radicle, attached to the scutellum and pointed 
 towards the smaller end of the seed. Make longitudinal 
 sections through the radicle and examine the rootcap 
 and the rootsheath, or coleorhiza. Study the development 
 
 FIG. 141. Transverse section through upper part of a 
 Cornstalk, as seen under low power, (x 35.) 
 
THE SPERMAPHYTES. 
 
 223 
 
 of the apical bud and radicle in seedlings from a few days 
 to some weeks old. 
 
 3. Make a thin, median longitudinal section through 
 the developing radicle of a seedling. Study the loosely 
 arranged cells of the older portion of the rootcap at the 
 very end of the root ; above these are more compact and 
 regularly' arranged newer cells of the rootcap. Just 
 above these at the apex of the root proper is the growing 
 point of the root. Pro- 
 ceeding from the grow- 
 ing point, study the 
 
 differentiation of the 
 cells for a short dis- 
 tance back into the root. 
 Notice particularly col- 
 umns of broad, horizon- 
 tally flattened cells. The 
 horizontal partitions in 
 these cells will eventu- 
 ally break away, and the 
 columns of cells will be 
 transformed into a ves- 
 sel with long cylindri- 
 cal segments. Find the 
 origin of the secondary 
 roots which, in median 
 sections, appear as dis- 
 tinct circular masses at 
 the junction between the 
 root and the stem. Fol- 
 low up the stem and lo- 
 cate developing leaves. 
 
 4. Cut transverse sections of the stem. Mount in 
 Schultze's solution. Describe the arrangement of the 
 fibrovascular bundles. Are they definitely placed as re- 
 
 FIG. 142. Fibrovascular bundle of Indian 
 Corn, Zea mays. Transverse section, as 
 seen under high power. 0, P, P, cells 
 of the ground parenchyma. The tissue 
 represented by thick dark-walled cells is 
 the bundle sheath ; E, E, pitted vessels ; 
 F, an annular vessel; A, spiral vessel; 
 L, empty space produced by the tearing 
 apart of the tissues in consequence of 
 rapid growth ; H, H, sieve tissue consti- 
 tuting the bast or phloem portions of the 
 bundle ; E, E, A, and F are the main ves- 
 sels of the xylem. The lower part of the 
 figure was situated towards the center of 
 the stem. (X 500.) 
 
224 PRACTICAL BOTANY. 
 
 gards the outside and the center of the stem ? Where 
 are they most abundant ? The space between the bun- 
 dles is filled with thin-walled fundamental parenchyma. 
 Trace this towards the outside of the stem, and notice 
 that it changes near the epidermis into thick-walled scle- 
 renchyma. Notice the same change as you approach the 
 fibrovascular bundles. Is the epidermis regular or irreg- 
 ular ? Find places in the epidermis where the section has 
 passed through stomata ; notice the guard cells. In con- 
 nection with this observation, mount bits of the epidermis 
 torn from the stem with the forceps, and study the sur- 
 face view of the stomata. 
 
 Find and identify in your section all the parts shown in 
 
 Fig. 142. Draw a fibrovascular bundle and label the parts. 
 
 5. Cut longitudinal sections through an internode, mount 
 
 in Schultze's solution, and identify all the above tissues 
 
 as seen in longitudinal sections. 
 Study the markings on the large 
 vessels. Trace some of the fibro- 
 vascular bundles as far as you can, 
 and state what you observe. 
 
 6. Cut transverse and longitu- 
 dinal sections through a node of 
 the stem, mount in dilute caustic 
 potash, and trace the fibrovascular 
 bundles in their passage through 
 the node. Notice especially the in- 
 tercommunication of the bundles. 
 
 7. Mount bits of the epidermis 
 torn from both the upper and the 
 
 FIG. 143. Epidermal cells lower sides of the leaf. Do you 
 
 and stomata of Corn. find stom ata on both sides ? Draw 
 
 a stoma under high power with its two guard cells and 
 
 two subsidiary cells. Are the stomata arranged in any 
 
 definite way ? Note the shape of the stomata when 
 
THE SPERM APHYTES. 225 
 
 mounted in distilled water; then run 10 per cent solution 
 of common salt under the cover and observe the changes. 
 
 8. Treat a piece of the leaf with Schultze's macerating 
 mixture until it is transparent. Examine it for fibro- 
 vascular bundles, noticing particularly the fine branches 
 that serve to connect the different bundles. How are the 
 main bundles arranged with reference to one another? 
 Where with reference to the bundles are the stomata 
 situated ? 
 
 9. Cut transverse sections of a well-developed leaf and 
 also of a very young leaf of a seedling. How do the sec- 
 tions of the fibrovascular bundles compare in the two 
 cases ? Draw a stoma as seen in cross section. 
 
 References for Reading. Goebel's " Classification of Plants," pp. 
 346-445 ; Vines' " Text-Book of Botany," pp. 489-569 ; Scott's " Struc- 
 tuval Botany," pp. 142-197; Arthur, Barnes, and Coulter's "Plant 
 Dissection," pp. 172-221; Bessey's "Essentials of Botany," pp. 
 225-251 ; Beyer's " Elementary Biology," pp. 155-161. 
 
 SUBCLASS II. The Dicotyledons. The characteristic 
 that has given the name to this subclass is the pair of 
 cotyledons in the embryo which develop simultaneously. 
 The leaves are usually netted- veined. The wood is ar- 
 ranged in bundles placed in a circle, or it forms a continu- 
 ous circle around the stem, though in the anomalous 
 dicotyledons it is arranged in bundles scattered irregularly 
 through the stem, at least in some portions of the plant. 
 The parts of the flowers are usually in fives or fours, 
 sometimes in threes. The flowers are sometimes incon- 
 spicuous and colorless, but are usually conspicuous and 
 with bright-colored corollas. 
 
 This subclass includes by far the largest number of 
 ordinary plants and trees ; it exhibits the greatest variety 
 of differentiation of stem, leaf, and flower, far surpassing in 
 these particulars all the other subdivisions put together. 
 
 CLARK'S EOT. 15 
 
226 PRACTICAL BOTANY. 
 
 As these exercises presuppose the previous study of the 
 gross morphology and the analysis of a considerable num- 
 ber of the plants of this subclass, the practical studies will 
 be directed to the minute anatomy of typical plants, with 
 the particular purpose of preparing for the consideration 
 of the physiology of the higher plants which follows. 
 
 THE DICOTYLEDONS. PRACTICAL STUDIES. 
 
 1. Examine bits of the epidermis torn from both the 
 upper and under surfaces of the leaves and from the young 
 
 and tender stems of a number of 
 different plants ; almost any of the 
 Dicotyledons will do : Nasturtium, 
 Sunflower, Bean, Shepherd's Purse, 
 Cabbage, Beech, Deutzia, and Fuchsia 
 are good. Mount in distilled water, 
 and, after observing the shape of the 
 stoma, note the changes brought 
 about by plasmolyzing with salt solu- 
 tion. Do you find stomata in equal 
 numbers on both the upper and the 
 FIG. 144. stomata of lower sides of the leaf ? Do you find 
 
 Lilac leaf. ,-, .^ . i * .*, 
 
 them on the epidermis of the stem? 
 
 Draw stomata as found on several different leaves, to- 
 gether with their guard cells and a few cells of the sur- 
 rounding epidermal tissue. Do you find chlorophyl in 
 the guard cells? In the epidermal cells? Do you find a 
 nucleus and nucleolus in the guard cells ? In the epider- 
 mal cells? 
 
 2. Place parts of leaves between pieces of pith, and cut 
 transverse sections. Notice carefully in what parts of the 
 section chlorophyl is found. Draw and label as many of 
 the parts as you can by comparison with Fig. 145, which 
 is a transverse section of a leaf of the Rubber Plant, Ficus 
 
THE SPERM APHYTES. 
 
 227 
 
 FIG. 145. Portion of a cross section of a 
 leaf of the Rubber Plant, Ficus elas- 
 tica. A, epidermis of upper side of 
 leaf ; B, palisade parenchyma ; C, 
 spongy parenchyma or mesophyll; D, 
 epidermis of under side of leaf ; under 
 E is a fibrovascular bundle ; F, a cysto- 
 lith ; G, a stoma with cavity above it. 
 
 elastica. In that figure A is the epidermis of the upper 
 side of the leaf. B is two rows of more or less rectangular 
 cells of the palisade parenchyma. C is the spongy paren- 
 chyma which constitutes the greater part of the interior 
 of the leaf. D is the 
 epidermis of the under 
 side of the leaf. E is a 
 section through a fibro- 
 vascular bundle which 
 forms the rib of the leaf. 
 F is a cystolith, an aggre- 
 gation formed by parti- 
 cles of carbonate of lime 
 which have collected on 
 a mass of cellulose that 
 has formed here abnormally ; it is supported by a stalk 
 
 from the surface of the 
 cell in which it has 
 formed. 6r is a sec- 
 tion through a stoma. 
 3. Study Fig. 146, 
 which is a transverse 
 section of the stem 
 of a house Geranium, 
 Pelargonium. It rep- 
 resents the herbaceous 
 type of dicotyledonous 
 
 FIG. 146. Portion of the cross section of the stems. E is a single 
 stem of a House Geranium, Pelargonium. . .. .. , 
 
 A, pith parenchyma ; B, cambium layer ; TOW ot Cells O the epl- 
 
 C, cortical parenchyma; D, cork layer; dermis with proiect- 
 E, epidermis ; F, xylem ; G, phloem. 
 
 ing hairs. At D are 
 
 several layers of cork cells. is the cortical parenchyma. 
 G- is the phloem or inner bark. B is the cambium layer 
 and is composed of extremely delicate, radially flattened 
 cells. F is the xylem or wood, which in this plant forms 
 
228 
 
 PRACTICAL BOTANY. 
 
 M 
 
 a continuous though somewhat irregular ring around the 
 stem. A is the pith parenchyma. 
 
 Cut transverse sections of the Geranium stem and ver- 
 ify the figure. In what parts do you find chlorophyl? 
 Starch ? In the cortical parenchyma find crystals. Treat 
 with acetic acid. If the crystals are composed of carbon- 
 ate of lime, they will dissolve with effervescence ; if they 
 are composed of oxalate of lime, they will not be dissolved. 
 
 If the crystals are 
 not affected, treat 
 with hydrochlo- 
 ric acid. This 
 acid dissolves the 
 carbonate of lime 
 with efferves- 
 cence; it dissolves 
 the oxalate of 
 lime without ef- 
 fervescence. 
 
 Treat a section 
 of Geranium stem 
 with Schultze's 
 solution. What 
 portions are com- 
 posed of normal 
 and what of lig- 
 
 FIG. 147. Radial section of mature Yellow Birch. 
 M, M, medullary rays ; S, S, S, scalarif orm ves- 
 sels, (x 35.) 
 
 nified cellulose ? Treat another section made from a fresh 
 green stem with dilute iodine. In what parts do you find 
 protoplasm? Do you find nuclei and nucleoli in any of 
 the cells? In what parts do you find starch? Look for 
 intercellular spaces, using high power, if necessary. Where 
 do you find them ? Under high power study the cell walls 
 of the large vessels in the xylem ; also in the phloem. 
 Make out three layers in the wall. 
 
 4. Cut longitudinal radial sections of the Geranium 
 
THE SPERMAPHYTES. 
 
 229 
 
 stem. Draw and locate all the tissues shown in Fig. 146. 
 Under high power examine the vessels of the xylem for 
 markings on the walls. Scalariform vessels, i.e., vessels 
 whose side walls are so marked as to resemble ladders ; 
 spiral vessels, i.e., vessels with a band running about 
 them spirally; annular vessels, i.e., vessels with rings of 
 thickened tissue at intervals; and pitted vessels may be 
 found in favora- 
 ble sections. In 
 the region of 
 the phloem, bast 
 fibers are found, 
 i.e., elongated, 
 narrow vessels 
 with pointed 
 ends ; also sieve 
 tubes, i.e., tubes 
 with more or 
 less circular 
 plates on their 
 surfaces which 
 serve as sieves 
 to allow the pas- 
 sage of certain Af 
 
 portions of the FIG. 148. Transverse section of mature Grape stem, 
 protoplasm from showing a number of annual layers, large and 
 small vessels, and medullary rays. (X 35.) 
 
 cell to cell. It 
 
 may not be easy to make these out. Treat pieces of the 
 stem with Schultze's macerating mixture, dissect them, 
 and search for all the above vessels. 
 
 5. Cut a transverse section of the Milkweed stem. 
 Draw it under low power and label all the parts you 
 can make out by comparing it with Fig. 146. It will be 
 seen that this stem corresponds very well with the Gera- 
 nium stem in structure. There is a tendency to divide 
 
230 
 
 PRACTICAL BOTANY. 
 
 the ring of xylem 
 into four parts, 
 or bundles, which 
 are, however, con- 
 nected by the cam- 
 bium layer which 
 ]\f forms a complete 
 ring. The cam- 
 bium in the bun- 
 dles is called fas- 
 cicular cambium ; 
 that between the 
 bundles, interfas- 
 cicular cambium. 
 
 FIG. 149. -Transverse section of mature Yellow o , . - . , 
 
 Birch, showing part of three annual layers. M, 
 
 M, medullary rays; S, S, scalariform vessels. of the Cortical pa- 
 
 renchyma, and just outside the inner phloem, are irregular 
 patches of dens- 
 er tissue ; these 
 are bundles of 
 bast fibers, and 
 associated with 
 them are latex D 
 tubes or laticifer- 
 ous vessels. The 
 latex tubes are 
 not, however, 
 confined to the 
 bundles of bast 
 fibers, but 
 spread as a very 
 delicate network 
 throughout 
 nearly all the tis- 
 sues of the stem. 
 
 B 
 
 FlG. 150. Transverse section of stem of Pipe?' futo- 
 kadsura. D, D, the normal ring of fibrovascular 
 bundles ; B, B, the second ring of bundles ; C, the 
 hollow center of the stem. Anomalous. (X 35.) 
 
THE SPERMAPHYTES. 
 
 231 
 
 Cut longitudinal radial sections of the Milkweed stem, 
 and study the scalariform, spiral, pitted, and annular 
 vessels of the xylem, and the bast fibers and sieve tubes 
 of the phloem. Also dissect a piece of the stem that has 
 been treated with Schultze's macerating mixture, and look 
 for these vessels. 
 
 6. Cut a transverse section of a well-developed Sun- 
 flower stem. Draw it under low power, and locate all the 
 parts you can by reference to Fig, 151, Notice that 
 the vascular tis- 
 sues are here sep- 
 arated into quite 
 
 a number of dis- 
 tinct fibrovascu- 
 lar bundles con- 
 nected by delicate 
 interfascicular 
 cambium. Each 
 bundle develops 
 on the inner side 
 into the large and 
 small vessels of 
 the wood ; on the 
 outside, into sieve 
 tubes and bast. 
 
 Cut longitudi- 
 nal radial sections 
 of the Sunflower stem, and study under high power the 
 scalariform, spiral, pitted, and annular vessels of the 
 xylem, and the bast fibers and sieve tubes of the phloem. 
 
 7. Cut and study in the manner indicated in the pre- 
 ceding exercises transverse and longitudinal sections' of 
 other herbaceous Dicotyledons. Artichoke, Blackberry, 
 Raspberry, Clematis, Evening Primrose, Pigweed, and all 
 other similar stems are good. 
 
 FIG. 151. Transverse section of the stem of Aris- 
 tolochia latifolia. A, the cambium layer ; B, the 
 xylem ; H, pith parenchyma ; E, the cortex or 
 bark; D, inner bark or phloem; C, cortical pa- 
 renchyma. 
 
232 
 
 PRACTICAL BOTANY. 
 
 FIG. 152. Transverse section of the petiole of Horse-chestnut. H, H, the 
 normal ring of fibrovascular bundles ; C, C, the centrally located bundles 
 which branch into the subdivisions of the leaf. (X 35.) 
 
 8. Cut transverse sections 
 of the petiole of Horse-radish. 
 This represents the anoma- 
 lous dicotyledonous type. 
 The wood is not arranged in 
 a circle, nor even in bundles 
 arranged in a circle, but the 
 fibrovascular bundles are scat- 
 tered about without definite 
 order. For another example 
 of the same type cut trans- 
 verse sections of the petiole 
 of Plantain. 
 
 9. Study Fig. 153, which 
 is a transverse section of the 
 stem of Basswood. It repre- 
 sents the arboreous type of 
 
 FIG. 153. Part of transverse 
 section of first year's growth 
 of stem of Basswood. (X 35.) 
 
THE SPERMAPHYTES. 
 
 233 
 
 the Dicotyledons. The section from which this figure 
 was photographed was cut late in the season, after the 
 activity of the cambium had ceased. It shows the 
 growth of one season. The inner side of the dark ring 
 at A represents the position of the cambium layer ; the 
 outer portion of the same ring is the phloem, or bast. B 
 is the parenchyma of the cortex. The outer row of cells 
 at is the epidermis. D is the xylem ; in it the large 
 openings are 
 principally sca- 
 larif orm vessels ; 
 the fibro vascular 
 bundles, which 
 form a complete 
 ring around the 
 stem, are much 
 crowded to- 
 gether, and the 
 compressed pa- 
 renchyma be- 
 tween them al- 
 ready begins to 
 assume the form 
 of medullary 
 rays. E is the 
 pith paren- 
 chyma. 
 
 Figure 154 shows a portion of a transverse section of an 
 older stem of Basswood taken near the pith. P is the 
 pith parenchyma. A is the first annual ring of the 
 xylem. B is a part of the second annual layer. Well- 
 developed medullary rays run through A and B. A shows 
 well the large vessels that develop in the first growth 
 and the small vessels that are formed in the latter part 
 of the season 
 
 FIG. 154. Transverse section of older Basswood stem. 
 A, wood of first annual ring; B, part of second 
 annual ring ; P, pith parenchyma. 
 
234 
 
 PRACTICAL BOTANY. 
 
 FIG. loo. Tangential section of Mountain Ash, show- 
 ing end views of the medullary rays, (x 35.) 
 
 10. Cut transverse, radial, and tangential sections of 
 other arboreous stems. By reference to Figs. 147 and 155 
 identify the various tissues. Maple, Birch, Elder, Elm, 
 Cherry, Apple, and Pear stems are favorable specimens. 
 
 Draw a portion 
 of each section, 
 indicating par- 
 ticularly any 
 differences you 
 find in the same 
 tissue in the dif- 
 ferent stems. 
 
 11. Imbed in 
 paraffin or cel- 
 lo i d i n apical 
 buds of Lilac, Artichoke, or Sunflower, and cut longi- 
 tudinal median 
 sections. Study 
 the thin-walled 
 cells of the api- 
 cal meristem ; 
 these cells have 
 abundant pro- 
 toplasm and are 
 in an actively 
 dividing condi- 
 tion. Near the 
 apex is the grow- 
 ing point. Trace 
 the cells of the 
 apical meristem 
 
 FIG. 156. Transverse section of Mountain Ash, showing 
 
 Stem, and notice a number of annual layers, medullary rays, the large 
 
 thpir rHffWpnti vessels formed in spring growth, and the small vessels 
 
 of late season growth. The right side of the figure 
 
 ation into the was situated towards the center of the stem, (x 35.) 
 
THE SPERMAPHYTES. 
 
 235 
 
 various tissues of the stem that have already been studied. 
 Notice also, particularly, that the meristematic cells are 
 identical in their nature and function with those of the 
 cambium layer. 
 
 12. Cut transverse, radial, and tangential sections of 
 the roots of the plants that have been used in Numbers 
 3 to 11, using both young and old portions of the roots. 
 Are the fibro- 
 
 vascular bun- 
 dles continued 
 into the roots ? 
 If so, do you 
 find that they 
 here exist in a 
 modified form? 
 Compare each 
 section with the 
 corresp onding 
 section of the 
 stem of the same 
 plant. Do you 
 find chlorophyl? 
 Do you find pro- 
 
 , FIG. 157. Bristly Sarsaparilla, showing the anomalous 
 toplasm in the arrangement of the fibro vascular bundles, (x 35.) 
 
 cells of the root? 
 
 If so, in what parts? Treat with iodine. Do you find 
 
 a nucleus and nucleolus ? Starch ? 
 
 13. Germinate beans of some large variety until the 
 radicle is enlarged and is in an actively growing con- 
 dition. Imbed radicles in paraffin or celloidin, and cut 
 longitudinal median sections. Make out the rootcap. 
 Just back of this and near the apex of the root proper 
 find the growing point. Notice the thin-walled cells of 
 the meristem that have resulted from recent divisions of 
 the cells at the growing point. Trace these cells up 
 
236 
 
 PRACTICAL BOTANY. 
 
 into the radicle, and notice that they are continuous with 
 the cambium. 
 
 14. Examine the roots of the plants that have been 
 studied for root hairs. Do you find them on the young or 
 the old parts ? How far from the tips 
 of the roots are they located ? These ^^ ^ 
 
 hairs are the organs for the absorp- 
 
 159 
 
 FIG. 158. Cross section of a root. The typical structure of roots is shown ; 
 
 also the manner in which the root hairs apply themselves to particles of 
 
 dirt to obtain nutriment from them. (After Franke.) 
 FIG. 159. Seedling of White Mustard. A, with the dirt clinging to the root 
 
 hairs ; B, after washing. (After Sachs.) 
 
 tion of the plant's food from the soil. In most cases they 
 excrete an acid cell sap which dissolves the solid mineral 
 constituents of the soil and pre- 
 pares them for entrance into the 
 root hair by osmosis. 
 
 Place a piece of highly polished 
 marble in a box, cover it with two 
 or three inches of clean sand, and 
 plant Beans and Peas in the sand. 
 Keep well watered and under f avor- 
 FIG. 160. Polished marble able conditions until the plants 
 corroded by the action have atta j ne( i considerable size. 
 
 of the sap from root 
 
 hairs. (After Detmer.) Then take out the marble and ex- 
 
THE SPERMAPHYTES. 
 
 237 
 
 amine it by reflected light for marks made by the cor- 
 roding action of the sap from the root hairs. Touch the 
 root hairs of some of the plants with blue litmus paper. 
 The change of color from blue to red shows the presence 
 of an acid. 
 
 15. Show that carbon dioxide is given off by growing 
 plants. 
 
 a. Soak Beans or Peas in water 
 over night, place them in a mod- 
 erately warm place on wet paper 
 during the day, and at night fill a &j 
 500 c.c. flask one third full of them. 
 Stopper the flask and keep it in a A 
 
 warm room over night. In the " 
 
 morning lower a lighted splinter into FlG - 161 - Arrangement 
 
 . , a , m, T . i ,1 of apparatus to show 
 
 the flask. Ihe carbon dioxide that that carbon di0 xide is 
 has been developed by the germi- given off by a s ro g 
 
 J plant. (After Mangin.) 
 
 natmg seeds puts out the flame. 
 
 b. Place a healthy growing plant under a bell jar over 
 night with a beaker of clear lime water. In the morning 
 
 notice that the union of the carbqn 
 dioxide given off by the plant with 
 the lime water has formed a film or 
 cloudiness of carbonate of lime. 
 
 16. Show that carbon dioxide is 
 necessary for growing plants. 
 
 a. Boil some water to expel the 
 carbon dioxide contained in it. After 
 it has cooled, cultivate in it any plant 
 that thrives wholly submerged in 
 water. The experiment is most suc- 
 FIG. if>2. Arrangement cessful when the vessel in which the 
 
 of apparatus to show , J , . .. , 
 
 that carbon dioxide culture is made can be closed by a 
 
 is given off by grow- stopper bearing a bulb tube Contain- 
 ing seedlings. (After 
 
 Sachs.) mg caustic potash or caustic soda 
 
238 PRACTICAL BOTANY. 
 
 through which fresh air is admitted deprived, of carbon 
 dioxide. Recall similar experiments performed with Spi- 
 rogyra and other Algae. 
 
 b. Stand cylinders, bearing healthy cultures of seed- 
 lings in Sachs' food solution, in a shallow dish of water. 
 Cover with a tubulated bell jar, so placed that the water 
 in the shallow dish seals the bottom. In the tubulature 
 insert tightly a rubber stopper bearing a bulb tube con- 
 taining caustic soda or caustic potash. Fresh air deprived 
 of carbon dioxide is admitted through the tube. Place 
 the whole in strong sunlight. Examine daily. Does the 
 plant continue to thrive ? More than one half of the solid 
 matter of plants is carbon. Plants thrive and attain their 
 best maturity in Sachs' solution which contains no carbon 
 in any form. They must therefore obtain it from the air. 
 
 17. Show that oxygen is necessary for growing plants. 
 
 a. Fill two ordinary chemical retorts, neck and all, with 
 water that has been boiled to expel the contained gases. 
 
 Put a few Peas or Beans in the bot- 
 tom of each retort, and stand the 
 retorts, neck down, in a vessel of mer- 
 cury. Let them stand twelve hours 
 to soften the seeds. Then run hydro- 
 gen gas into one from an ordinary 
 hydrogen apparatus, and into the other 
 FIG. 163. Tubes for blow ordinary air by means of a bel- 
 
 the study of seed- , ,. . ,-, -, . 
 
 lings when deprived low s> inclining the retojts to dram out 
 
 of oxygen. (After the water. Allow both to stand, and 
 
 observe that the seeds in the retort 
 
 containing h} 7 drogen do not germinate, while those in the 
 
 retort containing air develop. 
 
 b. On the bottom of a 500 c.c. flask place 011 a wet 
 filter paper a layer of Barley that has been soaked in 
 water twelve hours, and stand a test tube containing a 
 strong solution of caustic potash in the flask. Stopper 
 
THE SPERMAPHYTES. 
 
 239 
 
 the flask with a rubber stopper having a bent tube. 
 Place the hands on the flask to warm it and drive out 
 some of the air, and then support it with the outer end 
 of the bent tube dipping under mercury. As the Barley 
 germinates, the carbon dioxide given off is absorbed by 
 the caustic potash solution. The oxygen of the air in 
 the flask is used by the plant, as is evidenced by the mer- 
 cury which rises to offset the tendency to form a vacuum 
 in the apparatus. 
 
 18. Show that heat is produced by germinating seeds. 
 Fit two 500 c.c. flasks with stoppers bearing thermometers. 
 Fill one of the flasks one third full of 
 
 Peas that have been soaked in water 
 twelve hours, letting the bulb of the 
 thermometer be well covered with 
 Peas. Note the reading of the two 
 thermometers. Set both flasks in 
 same conditions, and after some hours 
 take the readings of the thermometers 
 again. Has heat been produced by 
 the germinating seeds ? 
 
 19. Study the food materials neces- 
 sary for the healthy growth of plants. 
 Germinate seeds of Peas, Beans, and 
 Buckwheat on clean sand until they 
 are well started. Transfer some to 
 pots of ordinary loam. Make cultures 
 of others as follows : Fit large test 
 
 tubes or small cylinders with corks that have been split 
 vertically and the centers somewhat hollowed to allow 
 room for the seedling. Secure a seedling in each cork by 
 means of asbestos fiber so that its root will dip in the 
 solution to be placed in the cylinder. In one cylinder 
 place distilled water ; in another ordinary well or river 
 water ; in several others Sachs' solution for green plants, 
 
 FIG. 164. Cylinder for 
 the cultivation of 
 seedlings in differ- 
 ent solutions. (After 
 Hansen.) 
 
FIG. 165. Apparatus showing arrangements for the cultures in Number 19. 
 (From Vines, after Nobbe.) 
 
 240 
 
THE SPERMAPHYTES. 241 
 
 omitting in succession one ingredient of the solution. 
 Place in the sunlight arid under favorable conditions of 
 warmth, and renew the solutions about once a week. 
 From a comparison of the results, what elements do you 
 think are necessary for the healthy growth of green 
 plants. Renew the solutions again, adding the missing 
 ingredients. What is the effect on the plants? Com- 
 pare the root hairs in each case with those formed on 
 plants growing in the soil in the pots. State what you 
 notice. Do the plants grown in watery cultures need as 
 abundant root hairs as those grown in soil ? 
 
 20. Germinate some Beans or Peas until the radicles 
 are half an inch long. Grind them to a pulp with water. 
 Test a portion for sugar as follows : Add a little caustic 
 soda solution and then a little copper sulphate solution. 
 This treatment will give a reddish brown color, if sugar is 
 present. Do the germinating seeds contain sugar? Test 
 another portion of the solution for starch with iodine solu- 
 tion. Do the germinating seeds contain starch? Test 
 another portion of the solution for proteids by adding 
 a few drops of a solution made by dissolving a small drop 
 of mercury in nitric acid. Acid enough must be used 
 to dissolve the mercury entirely. This is known as 
 Millon's reagent ; it gives a red color with proteina- 
 ceous substances. Do the germinating seeds contain 
 proteinaceous substances ? 
 
 21. How do the food materials get into the plants ? 
 Cover the mouths of four thistle tubes with bladder. Fill 
 one of the tubes held mouth down with water containing 
 all the sugar it will dissolve to a point about one centi- 
 meter above the bulb. Stand it mouth down in a beaker 
 of water so that the water in the beaker and the sugar 
 solution in the tube are at the same level. Fill another 
 tube similarly with water, to which a quantity of starch 
 has been added, and arrange it in a beaker of water in the 
 
 CLARK'S BOX. 16 
 
242 
 
 PRACTICAL BOTANY. 
 
 same way. Fill a third tube with water and starch after 
 boiling. Fill a fourth tube with boiled starch and water, 
 to which a small amount of diastase 
 of malt has been added. After some 
 time observe whether water has entered 
 the thistle tubes by osmosis through 
 the diaphragm, and risen in their stems. 
 Test a little of the original solution 
 for sugar. Test the water in the first 
 beaker for sugar. Has sugar passed 
 through the bladder into the water? 
 Also taste the water. 
 
 Test a little of the original starch 
 solution with iodine solution, after di- 
 
 FIG. 166. Apparatus . 
 
 for the study of os- luting with ten times the volume of 
 mosis. (After Mill- water> The characteristic blue color 
 
 is obtained. Test the water in the 
 beaker for starch. Do you find it? Test the water in 
 the second, third, and fourth beakers for starch in the 
 same way. Has starch passed through the bladder into 
 the water? Test the water in these three beakers for 
 sugar. Do you find it in any case ? What is your con- 
 clusion from these tests ? 
 
 The experiment may be varied by using, instead of the 
 thistle tubes, short pieces of glass tubing with the ends 
 covered with bladder. 
 Each piece of tubing so 
 arranged represents very 
 
 wall Q Wlanf nail i 
 Well a plant cell im- 
 
 mersed in water. 
 
 FIG. 167. Imitation plant cell for the 
 study of osmosis. (After Oels.) 
 
 Substances that will pass through membranes by osmosis 
 are called crystalloids; substances that will not so pass 
 are called colloids. 
 
 22. Prove that some diastatic ferment is present in 
 germinating seeds. Germinate some Barley until it is 
 
THE SPERMAPHYTES. 243 
 
 well started, grind to a pulp, mix with water, and let it 
 stand one or two hours, filter, and add some thin boiled 
 starch. Test for starch with iodine at intervals of half 
 an hour. The diminishing intensity of the blue color 
 shows that the starch is diminishing in quantity ; it finally 
 wholly disappears. Test for sugar. Is it found ? What 
 do you conclude as to the presence of a diastatic ferment 
 in the germinating Barley? 
 
 23. Prove that the starch in a plant is a reserve food 
 to feed the plant at times when the formation of new food 
 materials is impossible ; also that a plant can convert 
 sugar into starch. Keep a Geranium or Nasturtium in 
 the dark for a day or two. Test bits of the leaf for 
 starch by dissolving out the chlorophyl with hot alcohol 
 and applying iodine solution. After a time the failure 
 to obtain the blue color proves that no new starch is 
 being formed in the absence of the sunlight, and that the 
 starch previously formed has been used up or transferred 
 to other parts of the plant. Now cut leaves from the 
 plant and place them with the cut ends in a beaker of 
 sugar solution in the dark. Test bits of these leaves 
 daily, after two or three days, for starch until you find 
 that some has been formed. 
 
 24. How do the nutrient fluids get to the portions of 
 the plants that are raised in the air? 
 
 a. Arrange capillary glass tubes, i.e., tubes of very 
 small bore, so that their ends dip into water. Arrange 
 in the same way a lamp wick and a piece of Pine wood. 
 The water can rise a certain height by capillary attraction. 
 It can in no case rise so as to flow over the top of the 
 tube unless the top is in contact with some other object. 
 Will capillarity account for the rise of water in large 
 plants ? 
 
 b. Cut off a Geranium plant a short distance above the 
 soil, and attach to the stump by means of a piece of rubber 
 
244 PRACTICAL BOTANY. 
 
 tubing a glass tube arranged vertically. See that the 
 joints are perfectly tight. The sap soon rises into the 
 glass tube. Observe its height from day to day. It is 
 forced up by what is known as root pressure. This ex- 
 periment is most successful in the spring. 
 
 c. Fill a thistle tube, having a bladder diaphragm over 
 its mouth, with water, and stand it, mouth up, with the 
 lower end of the stem dipping into mercury. Observe 
 
 FIG. 168. Apparatus to show the lifting effect of evaporation through a 
 
 membrane. (After Oels.) 
 
 FIG. 169. Apparatus to show the effect of root pressure. (After Detmer.) 
 FIG. 170. Apparatus to show the lifting effect of transpiration from the 
 
 leaves. (After Detmer.) 
 
 that the water evaporates through the membrane and the 
 mercury rises in the stem of the tube. Keep it under 
 observation for some days. 
 
 d. Arrange a glass tube so that one end dips in mer- 
 cury. Fill the tube with water. Fasten the top of the 
 Geranium used in b by means of a rubber stopper so that 
 its end will dip in water, making the joints air tight. 
 Because of the transpiration of the water from the leaves, 
 
THE SPERMAPHYTES. 245 
 
 the volume of the water in the tube is diminished, and the 
 mercury rises into the tube. 
 
 25. Show that the presence of sunlight is necessary for 
 the healthy development of plants. 
 
 a. Place plants that are growing healthily in a dark 
 room. Keep all other conditions favorable. Examine at 
 intervals for several weeks. Do they continue healthy? 
 Do they grow more or less rapidly than in the light? 
 
 b. Weigh each of a number of Peas and Beans. Ger- 
 minate them, using Sachs' food solution. After they are 
 well started keep one half in the sunlight and the other 
 half in the dark, all other conditions being alike and 
 favorable. After three or four weeks remove the seed- 
 lings, rinse in water, and dry for a week at the ordinary 
 temperature and protected from dust. How do the 
 weights compare with the original weights of the seeds? 
 What conclusion do you draw from the experiment? 
 
 c. Cut transverse sections of leaves that grow in the 
 bright sunlight and of those that grow in the dense shade 
 of the interior of a thickly leaved tree. Leaves of Beech 
 are good. Compare the palisade parenchyma produced 
 under the different conditions. What conclusion do you 
 draw ? 
 
 26. Study the movement of the nutrient fluids. 
 
 a. Girdle a young tree by removing the bark and the 
 youngest layer of wood. The tree continues to live for 
 some months. This proves that the nutrient fluids ascend 
 in the older wood, and not in the bark portions. The tree 
 dies before the second season. This proves that the 
 nutrient fluids, elaborated into foods in the leaves and 
 other portions of the plant, could not descend to nourish 
 the roots, and there to be stored up for future growth 
 of the plant. These fluids must therefore descend in the 
 bark portions of the plant. 
 
 b. Place the cut end of a Geranium stem in a solution 
 
246 
 
 PRACTICAL BOTANY. 
 
 of eosin in water. After a time remove, rinse in water, 
 and make transverse cuts at gradually increasing distances 
 from the lower end. In what tissues did the colored 
 solution rise the highest ? Make also longitudinal sec- 
 tions of a piece of stem similarly treated. 
 
 c. Remove a zone of bark and the youngest layer of 
 wood from a Willow branch, leaving the bark intact for 
 about two inches on the lower end. Place in water so 
 that the peeled portion and about an inch of the bark 
 above it are wholly covered with water. The branch 
 grows and forms new roots from the bark above, but none 
 from the bark below the peeled portion. This proves 
 that the nutrient materials for the roots descend in the 
 bark portions. 
 
 27. Plants do work. 
 
 a. Plants not only raise their aerial portions into the 
 air against the force of gravity, 
 and carry up food material from 
 the soil, but they can carry up 
 weights attached to the branches. 
 The roots force their way down- 
 ward into the soil in some cases 
 against great resistance. The split- 
 ting and moving heavy stones by 
 the roots of trees are familiar ex- 
 amples. 
 
 b. Counterpoise a delicate beam 
 balance, using damp sand for the 
 purpose in both pans. By the side 
 of one pan support in the horizon- 
 tal position a Bean seedling with 
 a radicle half an inch long, with 
 the radicle lying lightly but not 
 pressing upon the pan of the balance. The Bean itself 
 should rest in a drop of water, and the whole should be 
 
 Fia. 171. Arraugement of 
 apparatus for measuring 
 the work done by the 
 radicle of a seedling. 
 (After Mangin.) 
 
THE SPERMAPHYTES. 
 
 247 
 
 FIG. 172. Seedling of Bean, 
 showing positive geotro- 
 pism. G is a bell jar 
 standing in an open dish, 
 B, which contains water; 
 S, the seedling. (After 
 Detmer.) 
 
 placed in strong sunlight with favorable conditions of 
 heat. In two or three hours the radicle obeying geotro- 
 pism pushes the pan of the balance down. 
 
 28. Study geotropism. Germinate Beans until the 
 radicles are half an inch long. Pin the Beans to large 
 corks, and insert the corks in 
 
 bottles nearly full of water so 
 
 that the radicles are placed hori- 
 zontally. Tip the bottles so as 
 
 to wet the seedlings. Place in 
 
 strong sunlight. After a time 
 
 notice that the end of the radicle 
 
 turns downward. It is positively 
 
 geotropic. The plumule tends to 
 
 turn upward. It is negatively 
 
 geotropic. Continue the study 
 
 of positive and negative geotropism, using young plants of 
 
 Onions, Tulips, and Hyacinths, 
 fixing them in horizontal posi- 
 tions after the growth is well 
 started, and supplying suitable 
 conditions for nutriment, light, 
 and heat. Also sow Peas or 
 Beans in a hanging sponge ; 
 keep well watered. After the 
 
 FIG. 173. -Young Onion plant, seedlings are well started, turn 
 
 showing negative geotropism. the SDOllge Upside down and 
 (After Frank.) j ii~u xu j- 
 
 study the changes in the direc- 
 tions of growth of the stems and roots. 
 
 29. Study heliotropism. 
 
 a. Grow seedlings of Canary Grass or Beans in a wet 
 sponge hanging in a box painted black on the inside. 
 The box should have a removable, light tight cover, and, 
 on the side toward a window, a hole which is closed with 
 a cork until the seedlings are well started. The cork is 
 
248 PRACTICAL BOTANY. 
 
 then removed. After three or four hours, remove the 
 top, and observe that the plants have turned towards the 
 
 light. They are pos- 
 itively heliotropic. 
 
 b. Grow seedlings 
 of Mustard in damp 
 sawdust until they 
 are well started. 
 Remove them from 
 
 FIG. 174. Dark box for experiments in helio- ^Q sawdust and 
 tropisra. (After Schleichert.) 
 
 support them by 
 
 means of bent wire, carrying thin pieces of cork, just above 
 the surface of water in a beaker. Holes should be made 
 in the cork, and each seedling should be placed with its 
 radicle pointing downwards in the hole, and then secured 
 with asbestos fiber. Set the beaker in a box arranged 
 as in a. After several hours of exposure to the light 
 admitted by the hole in the side of the box, examine and 
 record your observations. 
 
 c. Observe the positions of the leaves of various house 
 plants at different hours of the day. Do their positions 
 bear any relation to the direction from which the light 
 comes ? 
 
 d. Observe the tendrils of Grapevines, Virginia Creeper, 
 and other climbing plants. They are negatively helio- 
 tropic, and turn away from the sun towards the support- 
 ing wall. 
 
 30. Study hydrotropism. Provide a wooden box eight 
 or ten inches long and two inches deep, and without a 
 bottom. Tack mosquito netting over the bottom. Spread 
 on this a thin layer of sawdust, and place Beans and Peas 
 that have been soaked in water for twelve hours on this. 
 Fill the box with sawdust, and hang it at an angle of 40 
 or 50 with the horizon. Keep the sawdust damp by an 
 occasional spraying and in an atmosphere that is neither 
 
THE SPERMAPHYTES. 
 
 249 
 
 FIG. 175. Apparatus to show hydrotropism. 
 (After Sachs.) 
 
 too dry nor too damp. Sachs, the originator of the ex- 
 
 periment, recommends a dark closet, the floor of which 
 
 is occasionally 
 
 watered. If the con- 
 
 ditions are right, 
 
 the radicles, as they 
 
 emerge from the 
 
 lower part of the 
 
 box, will not obey 
 
 geotropism, but will 
 
 grow close to the 
 
 damp sawdust. In 
 
 an atmosphere that 
 
 is too moist, the rad- 
 
 icles obey geotro- 
 
 pism. In obedience 
 
 to the fact illus- 
 
 trated by this ex- 
 
 periment, plants send their roots towards sources of mois- 
 
 ture in the earth. The penetration of wells by the roots 
 
 of trees is a well-known 
 source for the contami- 
 nation of well water. 
 
 31. Study twining 
 movements. 
 
 a. Raise Beans in a 
 flower pot. Set a stake 
 in the pot. Do the seed- 
 lings move in the direc- 
 tion of the stake, or 
 mu st they be placed in 
 
 contact with it before 
 
 they begin to twine 
 around it ? Determine how long it takes for the tip to 
 make a complete revolution around the stake. 
 
 FIG. 176. A, part of a plant of Convoi- 
 
 vulus arvemis; 5, part of a Hop vine. 
 (After Edmonds.) 
 
250 PRACTICAL BOTANY. 
 
 b. Make similar observations on the Hop and the Honey- 
 suckle. Do the Bean, Hop, and Honeysuckle twine about 
 the stake in the same direction ? 
 
 32. Study other autonomous movements of plants. 
 
 a. Observe the position taken by the leaves of various 
 plants during the different hours of the day. The leaves 
 move in such a way as to present their upper surfaces in 
 such a manner as to receive a favorable amount of heat 
 and light from the sun. In cases where the full light and 
 heat would be too much for the plant, other positions are 
 taken. Observe and record some instances in which the 
 plant presents its upper surface in a position nearly per- 
 pendicular to the direction of the sun's rays through the 
 day. 
 
 b. Place a clump of Clover plants together with consid- 
 erable earth clinging to the roots in a flower pot, or use 
 seedling Cabbages or Sunflowers. Study circumnutation 
 by Darwin's method. Insert a small stick firmly in a ver- 
 tical position, and, by means of pieces of gummed paper so 
 applied that they will not injure the plant, fasten the peti- 
 ole of a healthy leaf to the stick, leaving the blade of the 
 leaf projecting above the top of the stick. By means of 
 shellac, dissolved in alcohol, fasten a light glass thread, 
 made by drawing out a glass rod, along the midrib of the 
 leaf, and allow it to project half an inch bej^ond the tip of 
 the leaf. Place the plant where it will receive the light 
 from above. A convenient arrangement is to place the 
 plant in the bottom of a deep box painted black on the 
 inside, and reflect the light down through the open top by 
 means of a mirror. Arrange a graduated scale opposite 
 the glass index. Observe the position of the index at dif- 
 ferent hours of the day and record the results. 
 
 33. Sleep of plants. 
 
 a. Observe the position of the Clover, Wistaria, Wood 
 Sorrel {Oxalis acetosella), young plants of other species 
 
THE SPERMAPHYTES. 
 
 251 
 
 FIG. 177. Leaf of Oxalis carnea. 1, the ordi- 
 nary day position ; 2, night position. (After 
 Sachs.) 
 
 of Oxalis, Impatiens, or Beans during the daylight and 
 again as darkness comes on. 
 
 b. Observe the flowers of Morning Glory, Mayweed 
 (Ma rut a cotula, 
 
 D. C.) of the culti- 
 vated Daisy (Bellis 
 perennis) during the 
 day and again late 
 in the afternoon. 
 
 c. In the earlier 
 part of the day place 
 an Oxalis growing 
 in a pot in a large 
 box painted black 
 on the inside and 
 from which all light 
 
 is excluded. In two or three hours examine the posi- 
 tion of the leaves. Make similar observations by invert- 
 ing a box over Clover plants growing naturally out of 
 
 doors. Make the 
 box light tight all 
 around. 
 
 This change of 
 position is brought 
 about by varia- 
 tions in the 
 growth of the cells 
 on the upper and 
 under sides. In 
 
 cases where the 
 
 movements are most distinct, this variation in growth 
 occurs in a distinct swelling at the base of the petiole 
 known as a pulvinus. Sections through the pulvinus 
 often show a distinct difference in the size of the cells. 
 The sleep movements of plants are believed to be pro- 
 
 FIG. 178. Leaves of a Beau, a, the day position 
 6, the night position. (After Detmer.) 
 
252 
 
 PRACTICAL BOTANY. 
 
 visions of nature to protect from too great radiation of 
 heat during the cool hours of the night. Darwin has 
 
 shown that leaves 
 which are prevent- 
 ed from taking the 
 positions natural to 
 them are killed or 
 seriously injured on 
 chilly nights, while 
 other leaves on the 
 same plant do not 
 suffer. This is but 
 a continuation of 
 the provision al- 
 ready noted under 
 
 FIG. 179. Leaf of the Scarlet Ruiiner, Phassolus vr -L. 09 i 
 multiflora, in the sleep position. (After Sachs.) 'Dumber 6A, Wiier 
 
 by nature provides 
 
 that plants shall receive or retain an amount of heat suited 
 to their individual needs. 
 
 ISO 
 
 FIG. 180. Upper portion of the leaf stalk of the Scarlet Runner, showing the 
 motile organs of the leaflet. A, day position ; B, night position. (After 
 Sachs.) 
 
 FIG. 181. C, cross section through the rigid portion of the stem of Scarlet 
 Kunner; D, cross section through a motile organ. (After Sachs.) 
 
THE SPERMAPHYTES. 
 
 
 !RSI' 
 253 
 
 34. Study movements due to irritation. 
 a. Shake a flower pot in which a Sensitive Plant (Mi- 
 mosa pudica) is growing, and watch the movements of the 
 
 FIG. 182. Leaf of the Sensitive Plant, Mimosa pudica. A, the ordinary day 
 position ; B, after irritation. (After Duchartre.) 
 
 petioles, the secondary petioles, and the leaflets. Note the 
 time that elapses before the leaves return to their former 
 positions. Kepeat the shaking. Does the plant respond 
 to the irritation with the same 
 promptness ? Strike a sharp blow 
 with a pencil on a pair of ter- 
 minal leaflets. Observe that the 
 stimulus travels to the other leaf- 
 lets of the same leaf, and perhaps 
 even to other leaves. Touch in 
 succession with the sharp point of 
 a pencil the upper and the under 
 sides of the pulvinus. Does the 
 plant respond in either case ? This 
 plant may be grown from seed. 
 
 b. Shake vigorously a flower pot containing plants of 
 Oxalis acetosella or Oxalis stricta. It may be necessary 
 to repeat. Vigorous irritation causes the leaflets to sink 
 
 FIG. 183. Oxalis with leaves 
 in sleep position. (After 
 Hansen.) 
 
254 
 
 PRACTICAL BOTANY. 
 
 and take their sleep positions. Rub the under side of the 
 pulvinus for some time. Note the effect on the leaflets. 
 
 c. Venus' Flytrap, which grows native 
 in parts of North and South Carolina, is 
 not uncommon in conservatories and pri- 
 vate collections. The end of each leaf 
 is cut off from the lower part of the leaf 
 by incisions reaching to the midrib, and 
 is expanded into two lobes which can 
 fold up on the midrib as on a hinge. 
 The outer edge of each lobe bristles with 
 hairlike teeth, or tentacles. Each lobe 
 bears many glandular areas and three 
 hairlike spikes. Avoid these spikes, and 
 
 FIG. 184. -Leaf of , * .. . A 
 
 Venus's Flytrap, touch with a pencil point any other por- 
 
 Dionsea. 
 
 (After 
 
 of the lobes, . or marginal hairs. 
 Does the leaf show any movement ? 
 Touch the spikes. What is the result? Touch the hinges. 
 What is the result ? Observe how long 
 a time elapses before the leaf resumes 
 its former position. Place a small in- 
 sect in contact with one of the spikes. 
 Keep the plant under observation long 
 enough to see what happens. 
 
 d. The Sundew (Drosera rotundifolia) 
 is common, growing half buried in 
 masses of Sphagnum Moss in bogs. 
 Each individual plant consists of sev- 
 eral round leaves of a reddish color, 
 which lie prostrate, and an upright flower 
 stalk with whitish flowers. Each leaf 
 is borne at the end of a somewhat long 
 petiole. The petioles and the flower 
 stalk originate at a common center. Each leaf bears on 
 its surface, and especially around the circumference, hair- 
 
 tundifolia. Entire 
 plant. (After Ben- 
 tham.) 
 
THE SPERM APHYTES. 
 
 255 
 
 like tentacles. These are not true hairs. Each is pene- 
 trated by a branch from the fibrovascular system of the 
 leaf. At the tip of each is a minute gland which secretes a 
 
 186 187 
 
 FIG. 186. Leaf of Drosera rotundifolia with its tentacles expanded. (After 
 
 Darwin.) 
 FIG. 187. Drosera rotundifolia with the tentacles of the left side contracted 
 
 and inclosing a bit of meat. (After Darwin.) 
 
 thick, sticky liquid. 
 Touch these tenta- 
 cles with bits of 
 meat or with in- 
 sects. What is the 
 result? Repeat, 
 using inorganic sub- 
 stances. Is the re- 
 sult the same as 
 before? Place bits 
 of meat on the inner 
 part of the leaf, but 
 not touching the ten- 
 
 FIG. 188. 1, the head of one of the tentacles 
 
 tacles. Keep Under O f Drosera rotundifolia, with a drop of the 
 
 observation for ten viscid secretion surrounding it; 2, a section 
 
 through the head, showing the structure. 
 Or fifteen minutes. Highly magnified. (After Darwin.) 
 
256 PRACTICAL BOTANY. 
 
 The viscid secretions of the Sundew and Venus' Fly- 
 trap, as is the case with the corresponding secretion of 
 other insectivorous plants, serve not merely to catch and 
 hold the insects, but they contain digestive ferments which 
 act upon the animal matter and break it down into forms 
 that can be taken into the plant to serve as food. 
 
 References for Reading. Goebel's " Outlines of Classification," pp. 
 445-472 ; Vines' " Text-Book of Botany," pp. 570-783 ; Scott's " Struc- 
 tural Botany," pp. 12-141; H.Marshall Ward's "The Oak"; Bower's 
 " Practical Botany." pp. 54-228 ; Strasburger and Hillhouse's " Prac- 
 tical Botany," pp. 311-372 ; Dodge's " Practical Biology," pp. 336-377 ; 
 Bidgood's " Elementary Biology," pp. 145-190 ; Huxley and Martin's 
 " Practical Biology," pp. 460-481 ; Arthur, Barnes, and Coulter's 
 " Plant Dissection," pp. 222-242 ; Bessey's " Essentials of Botany," pp. 
 251-278; Boyer's "Elementary Biology," pp. 162-166; Gray's "Struc- 
 tural Botany " ; Carpenter's " The Microscope," pp. 609-650 ; Darwin's 
 "Power of Movement in Plants "; Darwin and Acton's "Physiology 
 of Plants"; MacDougal's "Plant Physiology"; Goodale's "Physio- 
 logical Botany " ; Geddes' " Chapters in Modern Botany " ; Strasburger, 
 Noll, Schenck, and Schimper's " Lehrbuch der Botanik," pp. 131-260, 
 372-520. 
 
APPENDIX. 
 
 1. MATERIAL FOR LABORATORY USE. 
 
 The labor involved in conducting a class in the practical 
 laboratory study of Botany is much diminished by a little 
 care and forethought. Material for study cannot gener- 
 ally be found in nature when wanted in sufficient abun- 
 dance and variety for satisfactory work ; it should be 
 sought at the proper seasons of the year and should be 
 preserved for future use. As a rule, the cheapest and 
 best preservative is formalin (formic aldehyde) ; alcohol of 
 from 70 to 90 per cent strength may be used. The life 
 histories of plants cannot be fully studied at any time 
 during the year without the help of such material. In 
 many cases it costs little more time and trouble, when 
 plants in suitable condition have been found, to secure a 
 supply sufficient for two or three years. This stock 
 should be used to supplement the plants that can be 
 obtained in the fresh state at the time the study is made. 
 
 The lower microscopic forms should be cultivated in 
 the laboratory. The process is very simple, and a reason- 
 able amount of care will furnish abundant material. The 
 only apparatus necessary is a supply of jars or large bot- 
 tles the larger the better, but small ones will do and 
 plates of ground glass or ordinary window glass to cover 
 them and prevent too rapid evaporation of the water. 
 The mode of procedure is to place in these jars gather- 
 ings from different localities, cover with plates of glass, 
 put in warm places and, in most cases, in fairly strong 
 CLARK'S EOT. 17 267 
 
258 APPENDIX. 
 
 light. If the green plants are sought, exposure to direct 
 sunlight is advised. If Fungi are under cultivation, the 
 strong sunlight should be avoided. The light of almost 
 any ordinary room affords a sufficient variety of condi- 
 tions for nearly all sorts of cultivations, though some of 
 the Fungi may be raised to advantage in a damp cellar. 
 If the cultivations are being made during the summer 
 months, the temperature will take care of itself; in the 
 winter, to insure success, care must be taken that it does 
 not fall much below 70 F. at any time, day or night. 
 
 In making the collections, not only should the different 
 known plants be placed in separate jars and the jars be filled 
 with water from the native habitat, but gatherings of mud 
 and debris from even unpromising localities should be util- 
 ized. Such unpromising collections often yield most sur- 
 prising and interesting results. For. instance, the finest 
 forms of that most fascinating organism Pandorina 
 which the writer has ever seen were developed in a jar 
 in which a clump of violets were kept with just moisture 
 sufficient to give vigorous growth to the violets. 
 
 When rare plants or conjugating forms are secured, 
 some of them should be preserved in formalin or alcohol 
 to use in case subsequent cultures and search of the ponds 
 and streams fail to produce what is wanted. 
 
 A box with glass front and back and a plate of glass for 
 a cover is very useful for the cultivation of Vaucheria, 
 Liverworts, Mosses, Drosera, and many other like plants. 
 It should stand in a window and should have three or four 
 inches of good swamp mud in the bottom. 
 
 A large table, with a sink in its center provided with 
 running water, is also convenient for the cultivation of 
 many plants. Boxes of sawdust and earth arranged 
 around this table may be utilized for the production of 
 seedlings. Rich earth may be placed in the bottom of the 
 sink, and water plants may be grown. A small jet of 
 
APPENDIX. 259 
 
 water playing in the sink will keep the air moist or may 
 be used to spray the plants arranged around the sides of 
 the sink. The water jet should be connected with the 
 pipes by means of a flexible rubber tube so that it may be 
 moved about at will. 
 
 2. THE LABORATORY. 
 
 A room with northern exposure is to be preferred for 
 the laboratory, as the light from the north gives more uni- 
 form conditions for the use of the microscope. It should 
 be well lighted by large windows and should be supplied 
 with running water. The students' working tables should 
 have flat tops, with a raised rim at the back and sides to 
 guard against dropping reagent bottles and other appa- 
 ratus. A number of cabinets and dark closets are desir- 
 able for storing apparatus and collections of material for 
 study. 
 
 While a fully equipped laboratory is much to be desired, 
 still all the work described in this book may be advan- 
 tageously done in an ordinary schoolroom and on com- 
 mon desks. The entire cost of fitting up a Botanical 
 Laboratory with convenient appliances, including micro- 
 scopes, microtome, and accessory apparatus, is less than 
 the expenditure necessary for a Physical or Chemical Labo- 
 ratory, and the Botanical Laboratory, once equipped, calls 
 for very little expenditure from year to year. 
 
 3. THE MICROSCOPES. 
 
 Microscopes that are powerful enough for all the obser- 
 vations described in this course and that are good enough 
 to place in the hands of beginners may be imported, duty 
 free, for about 118.50. American-made microscopes of 
 equal desirability cost somewhat more. In the selection of 
 microscopes the quality of the objectives is of the greatest 
 
FIG. 189. Leitz Stand V. 
 (Cut furnished by The L. E. Knott Apparatus Co., Boston.) 
 
FIG. UK). Bansch and Lomb Stand AAB. 
 furnished by the Bausch and Lomb Optical Company, Rochester, N. Y.) 
 
 261 
 
262 APPENDIX. 
 
 importance, for in them is the real value of the instru- 
 ment. The stand and its mechanical conveniences are 
 of secondary consequence for the purposes of this work. 
 The different makers combine objectives and eyepieces in 
 various ways. Purchasers are cautioned to see that the 
 magnification is secured by using high-power objectives 
 and low-power eyepieces and ' not by high-power eye- 
 pieces and low-power objectives. 
 
 The accompanying illustrations are included to give 
 those who may need such information an idea of what is 
 necessary for this course. There are very probably other 
 equally good microscopes. If funds are plenty, more 
 expensive stands may be indulged in. 
 
 The Leitz Stand V (see Fig. 189), with objectives 3 
 and 7, eyepieces I and III, giving magnification from 60 
 to 525 diameters, may be imported, duty free, for about 
 $18.50. The Bausch and Lomb Optical Company make 
 a stand of about the same grade and another, their stand 
 AAB (see Fig. 190), which is superior in its mechanical 
 parts ; either of these stands should be equipped with two 
 eyepieces and two objectives, f and l or 1 inch, giving 
 magnifying powers of from 55 to 485 or 770 diameters. 
 
 Directions for the manipulation of the microscope, the 
 preparation of material for temporary examination, the use 
 of the microtome in cutting sections, methods of staining 
 and mounting for permanent preservation, and the pro- 
 cesses used in making photomicrographs, are given in the 
 author's " Practical Methods in Microscopy," 2d edition, 
 published by Messrs. D. C. Heath & Co., Boston. 
 
 4. ACCESSORY APPARATUS. 
 
 A microtome of some sort is a necessity. If one of the 
 more expensive instruments cannot be afforded, a simple 
 hand section cutter should certainly be obtained. The 
 
APPENDIX. 
 
 263 
 
 FIG. 191. Simple Hand 
 Section Cutter. 
 
 list price of the one shown in Fig. 191 is 16.00. Such an 
 instrument affords means of cutting sections in abundance 
 Avhen great delicacy is not of impor- 
 tance. To do more delicate work a 
 more perfect instrument is required. 
 If the laboratory is provided with one 
 of the larger microtomes, some form 
 of freezing attachment will reduce 
 very much the labor of making sec- 
 tions in large quantities. Of these, 
 that for the use of carbonic acid gas 
 is most to be desired. If this cannot 
 be afforded, Osterhout's attachment 
 for the use of ice water should be 
 obtained. It is listed at $2.50. The 
 writer has found it a thoroughly 
 practical and satisfactory accessory. 
 
 Of other apparatus, there should be a supply of glass 
 slips and cover glasses, dissecting needles, scalpels or 
 razors, watch glasses, Petri dishes of different sizes, flasks, 
 and beakers, all of which are comparatively inexpensive. 
 
 The teacher should gradually accumulate microscope 
 slides, and photomicrographs, to illustrate the more diffi- 
 cult points. These are especially to be commended in 
 the case of observations that would consume the time of 
 the class unwarrantably. Valuable additional instruction 
 may also be given in lectures and informal talks, espe- 
 cially if apparatus for projecting microscopic sections and 
 lantern slides is available. The L. E. Knott Apparatus 
 Company, Boston, have undertaken, at the writer's re- 
 quest, to furnish a set of lantern slides to illustrate this 
 course. They also furnish, at popular prices, new forms 
 of projection apparatus, using as the source of light arc 
 or incandescent electric lamps, acetylene gas, Welsbach 
 burners, or kerosene lamps. The slides will include about 
 
264 APPENDIX. 
 
 75 photomicrographs from the author's original negatives, 
 and many reproductions of figures in standard works on 
 Botany. 
 
 5. THE NOTEBOOK. 
 
 A careful record of the work done should be kept. 
 This record should not consist merely of answers to the 
 questions asked in the Practical Studies, but, so far as 
 time permits, the pupil should be asked to make compari- 
 sons of the different plants studied, using the results of 
 his own observations and material gathered by carefully 
 reading the references given. He should be required to 
 express plainly and accurately in clear, idiomatic English 
 and in drawings the carefully thought-out results of his 
 work. The notebook, when finished, should contain a 
 consistent bird's-eye view of the plant kingdom. It 
 should be an evidence of the pupil's growth in knowledge ; 
 but, even more important than this, it should be a means 
 of training him to the correct use of English in the ex- 
 pression of the ideas he has acquired. In the writer's 
 judgment, no subject in the school curriculum affords 
 more or better material for the solution of the " English 
 problem " in the schools than such a course of botanical 
 study properly carried out. 
 
 6. REAGENTS. 
 
 a. Formalin. Formalin, 1 part ; water, 70 parts ; 
 enough chrome alum to give a deep green color. This 
 is one of the best preservatives. 
 
 b. Alcohol of from 70 to 90 per cent strength may be 
 used as a preservative. 
 
 c. Iodine Solution. Make a saturated solution of po- 
 tassium iodide in water and add as much iodine as will 
 dissolve. This is the common test for starch. It turns 
 the starch granules blue or blue-black. 
 
APPENDIX. 265 
 
 d. Schultze's Solution. Dissolve as much metallic 
 zinc in hydrochloric acid as will dissolve ; then add as 
 much iodine as will dissolve ; filter through glass wool. 
 This is the test for cellulose ; it turns normal cellulose 
 blue or violet, fungous cellulose yellowish brown. 
 
 e. Schultze's Macerating Mixture. This consists of 
 nitric acid to which a few crystals of potassium chlorate 
 are added when used. This solution is used to separate 
 the fibers of woody tissues. The piece of plant should be 
 placed in a test tube, covered with nitric acid, and a little 
 potassium chlorate added. The tube should be heated to 
 the boiling point, and then its contents should be poured 
 into a large volume of water to stop the action and wash 
 out the acid. The plant tissues can then usually be easily 
 separated with dissecting needles. 
 
 /. Caustic Potash. The usual strength should be 
 1 g. of the solid to 20 c.c. of water. This is used as 
 a macerating fluid, and also to cause the cellulose con- 
 stituents of plants to swell and become more plainly visi- 
 ble under the microscope. 
 
 g. Millon's Reagent. Dissolve a small globule of 
 mercury in nitric acid and add an excess of the acid. 
 This solution is used to test for protein ; it turns protein- 
 aceous substances red. 
 
 h. Osmic Acid. This expensive reagent may be pur- 
 chased in tubes containing 1 g. each. The tube should 
 be broken under the surface of the water in which 
 its contents are to be dissolved, as the fumes from the 
 acid are very disagreeable and poisonous. One .gram to 
 500 c.c. of water is a good strength for ordinary use. The 
 solution does not keep well. It is the test for oils and fats. 
 
 i. Sulphuric Acid. The commercially pure acid should 
 be used either in full strength or diluted to various 
 degrees. This acid dissolves pure cellulose, but acts only 
 slightly on the older modified forms of cellulose. 
 
266 APPENDIX. 
 
 y. Sachs* Solution. Potassium nitrate, 1 g. ; sodium 
 chloride, 0.5 g. ; calcium sulphate, 0.5 g. ; magnesium 
 sulphate, 0.5 g. ; calcium phosphate, 0.5 g. ; distilled 
 water, 1 1. ; two or three drops of iron chloride. Heat. 
 Only a part of the calcium phosphate will dissolve. The 
 whole should be shaken each time a part of the stock 
 solution is taken for use. This is the nutrient solution 
 to be used in experiments on green plants. 
 
 k. Pasteur >s Solution. Water, 838 c.c. ; sugar, 150 g. ; 
 ammonium tartrate, 10 g. ; potassium phosphate, 2 g. ; 
 calcium phosphate, 0.2 g. ; magnesium sulphate, 0.2 g. 
 This is the solution to be used in the cultivation of the 
 chlorophyl-less plants. For some purposes, the sugar 
 may be omitted ; in other cases, its amount is sometimes 
 varied. 
 
INDEX. 
 
 Achlya prolifera, 135. 
 
 Adder Tongues, 187. 
 
 /Ecidiomycetes, 13, 121, 157. 
 
 ^Ecidiospores, 157. 
 
 ^Ethalium septicum, 50. 
 
 Agaricinese, 161 et seq. 
 
 Agaricus campestris, 160. 
 
 Albumen, 17. 
 
 Albuminous, 17. 
 
 Algse, 13, 70 et seq. 
 
 Alternation of generations, 9, 10, 58, 
 
 59, 185. 
 
 Amoeba, 47, 48. 
 Androecium, 206. 
 Anemophilous flowers, 25. 
 Angiosperms, 13, 15, 27, 206, 218 et seq. 
 Annular vessels, 217, 229, 231. 
 Annul us, 162, 195. 
 Anomalous dicotyledons, 232. 
 Anthei-idium, 36, 91, 108, 112, 116, 169, 
 
 174, 180, 181, 184. 
 Antherozoids, 10, 36, 38, 71, 77, 91, 109, 
 
 113, 116, 169, 174, 177, 180, 181, 184. 
 Apical bud, 190, 191, 207, 234. 
 Apical cell, 190, 191. 
 Apical meristem, 234. 
 Apogeotropism, 18. 
 Apothecium, 141. 
 Archegoniates, 10. 
 Archegonium, 10, 36, 38, 106, 169, 174, 
 
 177, 181, 182, 184. 
 Areolse, 171. 
 
 Ascent of nutrient fluids, 245. 
 Ascogonium, 156. 
 Ascomycetes, 13, 121, 136. 
 Ascospores, 136, 147, 149, 156. 
 Ascus, 136. 
 
 Autonomous movements, 250. 
 Auxospores, 58. 
 
 Bacteria, 13, 59, 63 et seq. 
 Basidia, Ki4. 
 
 Basidiomycetes, 13, 121, 160 et seq. 
 
 Basidiospores, 164. 
 
 Bast, 229, 230, 231. 
 
 Black molds, 125. 
 
 Blights, 138. 
 
 Blue-green slimes, 13, 59 et seq. 
 
 Boletus, 164. 
 
 Bordered pits, 215, 217 
 
 Botrychium, 187. 
 
 Brake Fern, 187 et seq. 
 
 Brittleworts, 106. 
 
 Brown Algae, 13, 71, 110. 
 
 Bryophytes, 9, 10, 13, 167 et seq. 
 
 Budding, 148. 
 
 Buds, 22. 
 
 Bunts, 122. 
 
 Button, 160. 
 
 Calyptra, 179. 
 
 Cambium, 213, 214, 230, 231. 
 
 Capillarity, 243. 
 
 Capitulum, 109. 
 
 Carbon dioxide, 22, 100, 237. 
 
 Carpel, 33. 
 
 Caulicle, 222. 
 
 Cedar apples, 158. 
 
 Cellular Cryptogams, 183. 
 
 Cellulose, fungous, 107. 
 
 Cellulose, test for, 75. 
 
 Chaetophora, 87. 
 
 Characeae, 104 et seq. 
 
 Chlamydospores, 127. 
 
 Chlorococcus, 81. 
 
 Chlorophyceae, 13, 71 et seq. 
 
 Chlorophyl, 42, 44, 46, 54, 59, 100, 211, 
 
 226. 
 
 Chromatophores, 100. 
 Chroococcaceae, 60. 
 Chroococcus, 60. 
 Chytridiese, 13, 121. 
 Cilia, 44, 111. 
 Circumnutation, 250. 
 
 267 
 
268 
 
 INDEX. 
 
 Cladophora, 88. 
 
 Cla varies, 161, 165. 
 
 Club Mosses, 13, 186, 202 et seq. 
 
 Coeloblastae, 71 et seq. 
 
 Coenobium, 78. 
 
 Coleochaeteae, <JO, 92, 93. 
 
 Colloids, 242. 
 
 Columella, 129. 
 
 Commensalisrn, 139. 
 
 Conceptacles, 114. 
 
 Cones, 209. 
 
 Conifers, 206 et seq. 
 
 Confer voideae, 71, 87. 
 
 Conjugate, 71, 93 et seq. 
 
 Contractile vacuoles, 49, 86. 
 
 Coral-shaped Toadstools, 161, 165. 
 
 Corn, 221. 
 
 Cotyledons, 15, 16. 
 
 Cross-fertilization, 25. 
 
 Crystalloids, 242. 
 
 Crystals, 228. 
 
 Cupules, 168, 169. 
 
 Cyanophyceae, 13, 59 et seq. 
 
 Cycads, 206. 
 
 Cyclosis, 107. 
 
 Cystopus, 130, 133. 
 
 Deliquescent stems, 27, 207. 
 
 Descent of nutrient fluids, 245. 
 
 Desmidieae, 94 et seq. 
 
 Desmids, 94, 95, 96. 
 
 Diastase, 243. 
 
 Diatomaceae, 13, 54 et seq. 
 
 Diatomin, 54. 
 
 Diatoms, 13, 54 et seq. 
 
 Dicotyledons, 15 et seq., 220, 225 et seq. 
 
 Dicotyledons, anomalous, 232. 
 
 Dioecious plants, 23. 
 
 Dionaea, 254. 
 
 Drosera rotundifolia, 254. 
 
 Eagle Fern, 187 et seq. 
 Elaters, 175, 200, 202. 
 Embryo, 16, 205, 218. 
 Embryo sac, 205, 209, 219. 
 Endochrome, 83, 89. 
 Endosmosis, 75. 
 Endosperm, 17, 209, 219. 
 Entomophilous flowers, 25. 
 Epidermis, 21, 213, 226, 233. 
 Equisetinae, 13, 186, 200 et seq. 
 Equisetum arvense, 200. 
 Equisetum sylvaticum, 200, 201. 
 
 Ergot, 147. 
 Euglena viridis, 45. 
 Eurotium, 155. 
 Exalbuminous seeds, 17. 
 Excurrent stems, 27, 207. 
 
 Ferns, 3, 13, 34 et seq., 183 et seq. 
 
 Fertilization of flowers, 24, 206, 219, 221. 
 
 Fibrovascular bundles, 10, 35, 179, 183, 
 211, 220, 224, 233. 
 
 Filicinae, 13, 186 et seq. 
 
 Fission plants, 13, 59, 63. 
 
 Flagellum, 46, 79, 85, 89. 
 
 Florideae, 71, 118, 119. 
 
 Flowering plants, 1, 15 et seq., 205 et 
 seq. 
 
 Flowers of Tan, 50. 
 
 Flowers, parts of, 23. 
 
 Flowers, anemophilous, 25 ; complete, 
 23; dioecious, 23; entomophilous, 
 25; female, 23; fertilization of, 24; 
 gamopetalous, 24 ; gamosepalous, 24; 
 hermaphrodite, 23 ; male, 23 ; monoe- 
 cious, 23 ; perfect, 23 ; pistillate, 23 ; 
 polypetalous, 24 ; polysepalous, 24 ; 
 staminate, 23. 
 
 Fruit, 26. 
 
 Fruit dots, 35. 
 
 Fucacese, 111 et seq. 
 
 Fucus vesiculosus, 112 et seq. 
 
 Funaria hygrometrica, 181. 
 
 Fungi, 13, 120 et seq. 
 
 Gamete, 3, 36, 38. 
 
 Gametophy-te, 3, 36, 38, 89, 167, 205. 
 
 Gamopetalous flowers, 24. 
 
 Gamosepalous flowers, 24. 
 
 Gasteromycetes, 161, 165. 
 
 Gemma, 10, 167, 170, 173. 
 
 Geotropism, 17, 129, 247. 
 
 Gill-bearing Toadstools, 161 et seq. 
 
 Gloeocapsa, 60. 
 
 Glycogen, 129. 
 
 Gonidia, 10, 76, 89, 132, 142, 164. 
 
 Gonidiophores, 135. 
 
 Green Algae, 13, 71 et seq. 
 
 Green Felts, 73. 
 
 Guard cells, 21. 
 
 Gymnosperms, 13, 31 et seq., 206 et seq. 
 
 Gyncecium, 206. 
 
 Haematococcus, 84. 
 Hairy-cap Moss, 177 et seq. 
 
INDEX. 
 
 269 
 
 Hanging-drop cultures, 129. 
 Haustoria, 130, 134. 
 Heat, 240. 
 
 Heliotropism, 18, 130, 247. 
 Hepaticae, 13, 167. 
 Herbarium mold, 155. 
 Heterocysts, 60. 
 Heterogamous union, 71. 
 Hilum, 16. 
 Hormogonia, 61. 
 Horsetails, 13, 186, 200 et seq. 
 Hydneee, 161, 165. 
 Hydrodictyon, 82. 
 Hydrotropism, 248. 
 Hymenium, 144, 164. 
 Hypha, 120, 127. 
 Hypocotyl, 15. 
 
 Indusium, 35, 196. 
 Innovation, 168. 
 Internode, 20. 
 Iodine solution, 74, 85, 100. 
 Isoetese, 204. 
 Isogamous union, 87. 
 
 Joint Firs, 206. 
 Kelp, 111. 
 
 Laminaria, 111. 
 Latex tubes, 230. 
 
 Leaf scars, 20. * 
 
 Leaves, 18, 19. 
 Lichens, 138, 139 et seq. 
 Liverworts, 13, 167 et seq. 
 Lycopodinae, 13, 186, 202 et seq. 
 Lycopodium clavatum, 203; compla- 
 natum, 203 ; dendroideum, 204. 
 
 Macrospores, 11, 205. 
 
 Manubrium, 109. 
 
 Marchantia polymorpha, 167 et seq. 
 
 Marattiaceae, 187. 
 
 Marsiliaceae, 186. 
 
 Medullary rays, 214, 215, 233. 
 
 Megazoospores, 85, 86, 89. 
 
 Meristem, 210, 234. 
 
 Mesophyll, 195, 211. 
 
 Mesocarpeae, 94, 103. 
 
 Micropyle, 16, 209. 
 
 Microspores, 11, 205. 
 
 Microzoospores, 83, 85, 87, 89. 
 
 Mildews, 13, 121, 125, 130. 
 
 Millon's reagent, 241. 
 
 Mimosa pudica, 253. 
 
 Molds, 13, 42, 121, 125. 
 
 Monocotyledons, 27 et seq., 220 et seq. 
 
 Monoecious plants, 23. 
 
 Mosses, 13, 38 et seq., 167, 176 et seq. 
 
 Moss plants, 9, 10, 13, 167 et seq. 
 
 Moon worts, 187. 
 
 Movements, autonomous, 250; due to 
 
 irritation, 253; twining, 249. 
 Mucorineae, 125. 
 Mucor mucedo, 126. 
 Mucor stolonifer, 127. 
 Musci, 13, 167 et seq. 
 Mushrooms, 160 et seq. 
 Mycelium, 120, 125. 
 Mycetozoa, 50. 
 Myxomycetes, 13, 50 et seq. 
 
 Nitella, 104. 
 Nodes, 20. 
 
 Nostocaceae, 60, 61, 62. 
 Nucellus, 207, 209, 210. 
 Nucleus, 102, 208, 235. 
 Nucleolus, 208, 235. 
 
 CEdogonieae, 90. 
 
 CEdogoiiium, 90 et seq. 
 
 Oil, test for, 75, 155. 
 
 Oogamous union, 71. 
 
 Oogonium, 76, 91, 113. 
 
 Oosphere, 10, 36, 38, 71, 116. 
 
 Oospore, 9, 10, 37, 38, 71. 91. 
 
 Operculum, 182. 
 
 Ophioglosseae, 187. 
 
 Oscillatorieae, 60, 61, 62. 
 
 Osmic acid, 75, 129, 155. 
 
 Osmosis, 18, 22, 44, 55, 128, 236, 242. 
 
 Ostiole, 114. 
 
 Ovary, 24, 218. 
 
 Ovule, 24, 207, 219. 
 
 Oxalate of lime, 228. 
 
 Oxalis, 253. 
 
 Oxygen, 22, 85, 101. 
 
 Pandorina, 78. 
 
 Paramoecium, 47. 
 
 Paraphyses, 116, 144, 147, 164, 180. 
 
 Parasite, 120. 
 
 Parenchyma, 211, 213, 224, 227, 233. 
 
 Parthenogenesis, 103, 106, 121, 135, 136. 
 
 Pasteur's solution, 129, 148, 152. 
 
 Pediastrum, 82. 
 
270 
 
 INDEX. 
 
 Pellicle, (58. 
 
 Penicilliura crustaceum , 153 ; glaucum, 
 
 152 et seq. 
 Peristorae, 182. 
 Perithecium, 147. 
 Peronosporeae, 130. 
 Phaeophyceae, 13, 110. 
 Phaeosporeae, 110, 111. 
 Phagocytes, 51. 
 Phloem, 212, 227, 231. 
 Phycocyanin, 59. 
 Phycoerythrin, 118. 
 Phycomycetes, 13, 121, 125. 
 Phycophaein, 110. 
 Phyllotaxy, 20. 
 Picric acid, 151. 
 Pileus, 162. 
 Pines, 206 et seq. 
 Pinna, 35. 
 Pinnules, 35. 
 Pistil, 218. 
 Pith, 26. 
 
 Pitted ducts, 231. 
 Plants, chlorophyl-bearing, 44; chlo- 
 
 rophyl-less, 44; holophytic, 44; sa- 
 
 prophytic, 44. 
 Plasm odium, 52. 
 Plasmolysis, 75, 150. 
 Plumule, 16, 222. 
 
 Pollen, 11, 23, 24, 25, 205, 208, 218, 219. 
 Pollen sac, 208. 
 Pollinodium, 156. 
 Polymorphism, 121. 
 Polypetalous flowers, 24. 
 Polyporieae, 161, 164 et seq. 
 Polysepalous flowers, 24. 
 Polytrichum commune, 177 et seq. 
 Pond scum, 40 et seq. 
 Primordial utricle, 75, 101. 
 Prolification, 177. 
 Promycelium, 122. 
 Protein, test for, 241. 
 Prothallium, 10, 11, 36, 37, 184, 198, 
 
 205. 
 
 Protista, 45, 50, 63, 64. 
 Protococcaceae, 71, 81 et seq. 
 Protococcus, 42 et seq., 81, 84 et seq. 
 Protonema, 10, 36, 40, 169, 177, 197, 
 
 198, 199. 
 
 Protoplasm, 44, 45, 49, 59. 
 Pteridophytes, 3, 13, 183 et seq. 
 Pteris aquilina, 187 et seq. 
 Ptomaines, 65. 
 
 Puccinia graminis, 157; maidis, 159; 
 
 rubigo-vera, 158. 
 Puff Balls, 161, 165. 
 Pulvinus, 251. * 
 Pyrenoids, 100. 
 Pyrenomycetes, 147. 
 
 Radicle, 16, 222, 235. 
 
 Raphidium, 81. 
 
 Red Alg33, 13, 71, 118, 119. 
 
 Resin ducts, 213, 215. 
 
 Resting spores, 52, 86, 91. 
 
 Rhachis, 35. 
 
 Rhizines, 141. 
 
 Rhizoids, 10, 38, 167, 172, 175, 179. 
 
 Rhizomes, 34, 188. 
 
 Rhodophyceae, 13, 71, 118, 119. , 
 
 Rivularieae, 60, 61. 
 
 Rockweeds, 111 et seq. 
 
 Root cap, 223 ; hairs, 17, 237 ; pressure, 
 
 18. 
 
 Roots, 27, 235. 
 
 Rotation of protoplasm, 107. 
 Rusts, 13, 121, 125, 157 et seq. 
 
 Saccharomyces, 138, 148 et seq. 
 
 Sac Fungi, 13, 121, 137. 
 
 Sach's solution, 101, 238, 239, 245. 
 
 Salvinaceae, 186. 
 
 Saprolegnieae, 135. 
 
 Saprophyte, 120. 
 
 Scalariform vessels, 229, 231, 2o3. 
 
 Scenedesmus, 81. 
 
 Schizomycetes, 13, 59, 63. 
 
 Schizophytes, 59. 
 
 Schultze's solution, 75, 85, 102, 114, 11(5, 
 129, 134, 143, 150, 179; macerating 
 mixture, 180, 192, 194, 225, 229. 
 
 Sclerenchyma, 35. 
 
 Scytonemeae, 60. 
 
 Sea Lettuce, 88. 
 
 Seed coat, 15, 16. 
 
 Seed plants, 3, 13, 205 et seq 
 
 Seeds, 26, 33, 206, 209, 219, 221. 
 
 Selaginelleae, 204. 
 
 Self-fertilization, 25. 
 
 Sensitive plants, 253. 
 
 Seta, 38, 179, 182. 
 
 Sieve tubes, 216, 229, 231. 
 
 Siphoneae, 71, 72 et seq. 
 
 Sleep, 250. 
 
 Slime Fungi, 13, 50 et seq. 
 
 Slipper animalcules, 47. 
 
INDEX. 
 
 271 
 
 Smut Fungi, 13, 121, 122. 
 Soredia, 145. 
 Sori, 35. 
 
 Spermaphytes, 9, 13, 205 et seq. 
 Spermatia, 145. 
 Spermatozoids, 10, 71. 
 k Sphseroplere, 90. 
 
 Spiral vessels, 217, 229, 231. 
 Spirogyra, 41, 98 et seq. 
 Sporangia, 36, 38, 128, 182, 195, 197. 
 Spore, 9, 36, 38, 198, 199, 202 ; resting, 
 
 52, 86, 91. 
 
 Sporophyte, 9, 36, 89. 
 Starch, test for, 74. 
 Stems, deliquescent, 27 ; excurrent, 
 
 27. 
 
 Sticta pulmonacea, 140. 
 Stigma, 24. 
 Stipe, 35. 
 Stomata, 21, 22, 114, 130, 171, 172, 194, 
 
 212, 224, 226 ; water, 22. 
 Stonewort, 106. 
 Style, -24. 
 Sugar, 241. 
 Sundew, 254. 
 Sunlight, 245. 
 Symbiosis, 139. 
 Symmetrical flowers, 30. 
 
 Taproot, 17. 
 
 Teleutospores, 157. 
 
 Testa, 16. 
 
 Tetraspora, 81. 
 
 /Thallophytes, 3, 13, 41. 
 
 Thallus, 3, 41, 121, 139. 
 
 Tilletia caries, 122, 123. 
 
 Toadstools, 13, 121, 160 et seq. 
 
 Tooth-bearing Toadstools, 161, 165. 
 
 Toxins, 65. 
 
 Trache'ides, 217. 
 
 Trama, 164. 
 
 Transpiration, 21, 244. 
 
 Trichogynes, 145. 
 
 Truffles, 138. 
 
 Tube-bearing Toadstools, 161, 164 et 
 
 seq. 
 Twining movements, 249. 
 
 Ulva, 88, 89. 
 Uredineae, 157 et seq. 
 Uredospores, 157. 
 Usnea barbata, 140. 
 Ustilagineae, 13, 121, 122. 
 Ustilago maidis, 123, 124. 
 
 Vacuoles, contractile, 49, 86. 
 
 Vascular Cryptogams, 183. 
 
 Vaucheria, 73 et seq. 
 
 Vaucheriacese, 73. 
 
 Velum, 162. 
 
 Venation, 19. 
 
 Venus' Flytrap, 254. 
 
 Vernation, 19. 
 
 Volva, 162. 
 
 Volvocinea3, 71, 77 et seq. 
 
 Volvox, 79. 
 
 Water Flannel, 88. * 
 Water mold, 125, 134. 
 Water net, 82, 83. 
 Wheat Bunt, 122. 
 Work, 246. 
 
 Xylem, 211, 215, 227, 231. 
 Yeast, 138, 148 et seq. 
 
 Zoogloea, 68. 
 
 Zoogonidia, 122. 
 
 Zoospore, 43, 58, 70, 76, 85, 87, 89, 113, 
 
 122. 
 
 Zygnemeae, 94, 97. 
 Zygospore, 9, 41, 58, 71, 89, 98, 102, 
 
 125, 127. 
 
 TYPOGRAPHY BY J. S. GUSHING & Co., NORWOOD, MASS., U.S.A. 
 
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