Elementary Botany

Part I. _physiology._ This Deals With the Life Processes of Plants,

as absorption, transpiration, conduction, photosynthesis, nutrition, assimilation, digestion, respiration, growth, and irritability. Since protoplasm is fundamental to all the life work of the plant, this subject is dealt with first, and the student is led through the study of, and experimentation with, the simpler as well as some of the higher plants, to a general understanding of protoplasm and the special way in which it enables the plant to carry on its work and to adjust itself to the conditions of its existence. This study also serves the purpose of familiarizing the pupil with some of the lower and unfamiliar plants.

Some teachers will prefer to begin the study with general morphology and classification, thus studying first the representatives of the great groups of plants, and others will prefer to dwell first on the ecological aspects of vegetation. This can be done in the use of this book by beginning with Part II or with Part III.

But the author believes that morphology can best be comprehended after a general study of life processes and functions of the different parts of plants, including in this study some of the lower forms of plant life where some of these processes can more readily be observed. The pupil is then prepared for a more intelligent consideration of general and comparative morphology and relationships. Even more important is a first study of physiology before taking up the subject of ecology. The great value to be derived from a study of plants in their relation to environment lies in the ability to interpret the different states, conditions, behavior, and associations of the plant, and for this physiology is indispensable. It is true that a considerable measure of success can be obtained by a good teacher in beginning with either subject, but the writer believes that measure of success would be greater if the subjects were taken up in the order presented here.

Part Ii. _morphology and Life History of Representative Plants._ This

includes a rather careful study of representative examples among the algæ, fungi, liverworts, mosses, ferns and their allies, gymnosperms and angiosperms, with especial emphasis on the form of plant parts, and a comparison of them in the different groups, with a comparative study of development, reproduction, and fertilization, rounding out the work with a study of life histories and noting progression and retrogression of certain organs and phases in proceeding from the lower to the higher plants. Thus, in the algæ a first critical study is made of four examples which illustrate in a marked way progressive stages of the plant body, sexual organs, and reproduction. Additional examples are then studied for the purpose of acquiring a knowledge of variations from these types and to give a broader basis for the brief consideration of general relationships and classification.

A similar plan is followed in the other great groups. The processes of fertilization and reproduction can be most easily observed in the lower plants like the algæ and fungi, and this is an additional argument in favor of giving emphasis to these forms of plant life as well as the advantage of proceeding logically from simpler to more complex forms. Having also learned some of these plants in our study of physiology, we are following another recognized rule of pedagogy, i.e., proceeding from known objects to unknown structures and processes. Through the study of the organs of reproduction of the lower plants and by general comparative morphology we have come to an understanding of the morphology of the parts of the flower, and of the true sexual organs of the seed plants, and no student can hope to properly interpret the significance of the flower, or the sexual organs of the seed plants who neglects a careful study of the general morphology of the lower plants.

Part Iii. _plant Members in Relation to Environment._ This Part Deals

with the organization of the plant body as a whole in its relation to environment, the organization of plant tissues with a discussion of the principal tissues and a descriptive synopsis of the same. This is followed by a complete study from a biological standpoint of the different members of the plant, their special function and their special relations to environment. The stem, root, leaf, flower, etc., are carefully examined and their ecological relations pointed out. This together with the study of physiology and representatives in the groups of plants forms a thorough basis for pure plant ecology, or the special study of vegetation in its relation to environment.

There is a study of the factors of environment or ecological factors, which in general are grouped under the physical, climatic, and biotic factors. This is followed by an analysis of vegetation forms and structures, plant formations and societies. Then in order are treated briefly forest societies, prairie societies, desert societies, arctic and alpine societies, aquatic societies, and the special societies of sandy, rocky, and marshy places.

Acknowledgments. The author wishes to express his gratefulness to all those who have given aid in the preparation of this work, or of the earlier editions of Elementary Botany; to his associates, Dr. E. J. Durand, Dr. K. M. Wiegand, and Professor W. W. Rowlee, of the botanical department, and to Professor B. M. Duggar of the University of Missouri, Professor J. C. Arthur of Purdue University, and Professor W. F. Ganong of Smith College, for reading one or more portions of the text; as well as to all those who have contributed illustrations.

Illustrations. The large majority of the illustrations are new (or are the same as those used in earlier editions of the author’s Elementary Botany) and were made with special reference to the method of treatment followed in the text. Many of the photographs were made by the author. Others were contributed by Professor Rowlee of Cornell University; Mr. John Gifford of New Jersey; Professor B. M. Duggar, University of Missouri; Professor C. E. Bessey, University of Nebraska; Dr. M. B. Howe, New York Botanical Garden; Mr. Gifford Pinchot, Chief of the Bureau of Forestry; Mr. B. T. Galloway, Chief of the Bureau of Plant Industry; Professor Tuomey of Yale University; and Mr. E. H. Harriman, who through Dr. C. H. Merriam of the National Museum allowed the use of several of his copyrighted photographs from Alaska. To those who have contributed drawings the author is indebted as follows: to Professor Margaret C. Ferguson, Wellesley College; Professor Bertha Stoneman of Huguenot College, South Africa; Mr. H. Hasselbring of Chicago; Dr. K. Miyake, formerly of Cornell University and now of Doshisha College, Japan; and Professors Ikeno and Hirase of the Tokio Imperial University. The author is also indebted to Ginn & Co., Boston, for the privilege to use from his “First Studies of Plant Life” the following figures: 28, 29, 46, 48, 49, 56, 62, 66, 67, 87, 102, 103, 422-426, 429, 430, 438-440, 443, 444, 448, 449, 452, 472-475. A few others are acknowledged in the text.

CORNELL UNIVERSITY, April, 1905.

TABLE OF CONTENTS.

Part I. Physiology.

CHAPTER I. PAGE PROTOPLASM. 1

CHAPTER II. ABSORPTION, DIFFUSION, OSMOSE. 13

CHAPTER III. HOW PLANTS OBTAIN WATER. 22

CHAPTER IV. TRANSPIRATION, OR THE LOSS OF WATER BY PLANTS. 35

CHAPTER V. PATH OF MOVEMENT OF WATER IN PLANTS. 48

CHAPTER VI. MECHANICAL USES OF WATER. 56

CHAPTER VII. STARCH AND SUGAR FORMATION. 60 1. The Gases Concerned. 60 2. Where Starch is Formed. 64 3. Chlorophyll and the Formation of Starch. 67

CHAPTER VIII. STARCH AND SUGAR CONCLUDED; ANALYSIS OF PLANT SUBSTANCE. 73 1. Translocation of Starch. 73 2. Sugar, and Digestion of Starch. 75 3. Rough Analysis of Plant Substance. 79

CHAPTER IX.. How Plants Obtain Their Food, I. 81

HOW PLANTS OBTAIN THEIR FOOD, I. 81 1. Sources of Plant Food. 81 2. Parasites and Saprophytes. 83 3. How Fungi Obtain their Food. 86 4. Mycorhiza. 91 5. Nitrogen gatherers. 92 6. Lichens. 93

CHAPTER X.. How Plants Obtain Their Food, Ii. 97

HOW PLANTS OBTAIN THEIR FOOD, II. 97 Seedlings, 97 Digestion, 107 Assimilation 109

CHAPTER XI. RESPIRATION. 110

CHAPTER XII. GROWTH. 118

CHAPTER XIII. IRRITABILITY. 125

PART II. MORPHOLOGY AND LIFE HISTORY OF REPRESENTATIVE PLANTS.

CHAPTER XIV. SPIROGYRA. 136

CHAPTER XV. VAUCHERIA. 142

CHAPTER XVI. ŒDOGONIUM. 147

CHAPTER XVII. COLEOCHÆTE. 153

CHAPTER XVIII. CLASSIFICATION AND ADDITIONAL STUDIES OF THE ALGÆ. 158

CHAPTER XIX. FUNGI: MUCOR AND SAPROLEGNIA. 177

CHAPTER XX. FUNGI CONTINUED (“Rusts” Uredineæ). 187

CHAPTER XXI. THE HIGHER FUNGI. 195

CHAPTER XXII. CLASSIFICATION OF THE FUNGI. 213

CHAPTER XXIII. LIVERWORTS (Hepaticæ). 222 Riccia, 222 Marchantia. 226

CHAPTER XXIV. LIVERWORTS CONTINUED. 231 Sporogonium of Marchantia. 231 Leafy-stemmed Liverworts. 236 The Horned Liverworts. 240 Classification of the Liverworts. 242

CHAPTER XXV.. Mosses (musci). 243

MOSSES (Musci). 243 Classification of Mosses. 248

CHAPTER XXVI. FERNS. 251

CHAPTER XXVII. FERNS CONTINUED. 262 Gametophyte of Ferns. 262 Sporophyte. 268

CHAPTER XXVIII. DIMORPHISM OF FERNS. 273

CHAPTER XXIX. HORSETAILS. 280

CHAPTER XXX. CLUB MOSSES. 284

CHAPTER XXXI. QUILLWORTS (Isoetes). 289

CHAPTER XXXII. COMPARISON OF FERNS AND THEIR RELATIVES. 292 Classification of the Pteridophytes. 295

CHAPTER XXXIII. GYMNOSPERMS. 297

CHAPTER XXXIV. FURTHER STUDIES ON GYMNOSPERMS. 311

CHAPTER XXXV. MORPHOLOGY OF THE ANGIOSPERMS: TRILLIUM; DENTARIA. 318

CHAPTER XXXVI. GAMETOPHYTE AND SPOROPHYTE OF ANGIOSPERMS. 325

CHAPTER XXXVII. MORPHOLOGY OF THE NUCLEUS AND SIGNIFICANCE OF GAMETOPHYTE AND SPOROPHYTE. 340

PART III. PLANT MEMBERS IN RELATION TO ENVIRONMENT.

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