IV PREFACE. 
a field in which we have made so little progress that very few 
people understand what is meant by the expression plant 
physiology. 
As a knowledge of the inner structure of plants is necessary 
to successful work in physiology, it is believed that a brief 
course in the elements of anatomy should precede the study of 
physiology. There are few books written in English which are 
available to the student of plant anatomy. De Bary’s “Com- 
parative Anatomy of Phanerogams and Higher Cryptogams” is 
invaluable as a reference book, but almost useless to a beginner. 
The design of the present little volume is to furnish a brief 
outline of the elementary principles of anatomy in a form avail- 
able to all students of botany who wish to use this science in 
any direction. or this purpose it is hoped it will meet the 
wants of several classes: those who expect to follow it witha 
more extended course in anatomy and physiology ; those who 
will take up the other line of work, descriptive and systematic 
botany ; and finally, students of pharmacy for whom the im- 
portance of a practical knowledge of the structure of roots, 
stems, and other parts of plants, can hardly be over-estimated. 
Aside from this, there is only one other feature which serves 
as an excuse for the appearance of another text-book, that is, 
the effort to present the subject from the developmental point 
of view. The experience of several years has demonstrated the 
superiority of this method over that in common use. It is 
hoped that a longer experience will serve to improve the present 
plan, not only by the eradication of its faults, but also by the 
more complete development of the idea underlying it. It may 
also be found practicable, at a later date, to combine with the 
present volume an elementary treatise on plant physiology, and 
