Throughout the book, it has often been convenient to refer to plants or their behavior in terms implying reasoning faculties. Of course, plants are never reasoning things, reasonable as many of their actions appear to be, and to ascribe such qualities to them is to saddle them with attributes perfectly foreign to the plant world. But the description of them in the terms of our everyday speech, the translation of plant behavior into the current conceptions of mankind, does so fix these in our minds that they cease to be among those interesting things that nearly everyone forgets. I have followed this method deliberately, understanding perfectly the objections to it, but believing, with the late C. E. Bessey, that in popular books “it is an admirable way of looking at some botanical things.” All of the half-tone illustrations, except two, are from the photographic collections of the Brooklyn Botanic Garden, and I am under the greatest obligation to the director of that institution for permission to publish them here. The illustration of the living and fossil algæ has been taken from Prof. Henry Fairfield Osborn’s “Origin and Evolution of Life,” with his kind permission. The illustration of desert vegetation is from a photograph by the late E. L. Morris, and kindly loaned from the collection of the Brooklyn Museum. All the line cuts in the text are from drawings made specially for this book by my wife, Bertha Fanning Taylor. While grateful and particular acknowledgments can be made for the illustrations, it is difficult or impossible to properly express my indebtedness to all those who, through their books and pamphlets, have indirectly aided in the making of this book. It would involve the mention of most of the better known writers of the books found in the larger botanical libraries. It is a pleasure to acknowledge help from Dr. M. A. Howe of the New York Botanical Garden on the literature of fossil and hot-spring algæ, and from Dr. Orland E. White of the Brooklyn Botanic Garden for helpful criticism of the section dealing with “How Plants Change Their Characters.” NORMAN TAYLOR. BROOKLYN BOTANIC GARDEN 20th October, 1920 CONTENTS CHAPTER PAGE INTRODUCTORY--PLANTS AND OUR DAILY NEEDS 9 I. WHAT PLANTS ARE 13 II. PLANT BEHAVIOR 76 III. HOW PLANTS PRODUCE THEIR YOUNG 116 IV. THE FAMILIES OF FLOWERING PLANTS AND THEIR RELATIONSHIP 168 V. USES OF PLANTS TO MAN 208 VI. GARDEN PLANTS 267 VII. HISTORY OF THE PLANT KINGDOM 298 VIII. DISTRIBUTION OF PLANTS 337 LIST OF ILLUSTRATIONS