PREFACE ix 



touched on or suggested in the first two chapters. In 

 Chapters IX and X the plant kingdom is considered in the 

 evolutionary sequence. 



The Questions and Suggestions which follow the chap- 

 ters are of two kinds. Some are designed merely to serve 

 as an aid in the study of the text, while others suggest 

 study and inquiry outside of the text. Of this latter kind 

 there are more than any one student is expected to cover. 

 Selection will be made of such as are most suitable to 

 local conditions. 



Technical terms have been used only as real need for 

 them has been developed. Upon first occurrence they are 

 printed in italics. 



Attention is called to the classified tables of terms which 

 immediately precede the Index. These are designed to 

 serve the student in review, and to be a general guide to 

 the relative values of the facts presented. 



Acknowledgments. — The sources of this book lie in 

 modern botanical literature in general, but the chief source 

 has been the Coulter, Barnes, and Cowles " Textbook 

 of Botany." For spirit of treatment as well as for data, 

 I am much in debt to Dr. Cowles's part of that work, 

 the part on ecology. That work is also the chief source 

 of the non-original illustrations used herein. The illus- 

 trations which are original are all the work of Miss Anna 

 Hamilton. For critical reading of the manuscript I am 

 gratefully and especially indebted to my father, Dr. John 

 M. Coulter, to Dr. Cowles, and to Dr. Crocker. 



JOHN G. COULTER. 

 Bloomington, III., July, 1913. 



