SOTA)

FIRST EDITION

SECOND IMPRESSION

MCGRAW-HILL BOOK COMPANY, INC.

NEW YORK: 370 SEVENTH AVENUE

LONDON: 6 & 8 BOUVERIE ST., E. C. 4

1921

COPYRIGHT 1921; BY THE McGRAW-HILL BOOK COMPANY, INC.

PREFACE

The author has had in mind a two-fold purpose in the preparation of this
book. First, it is hoped that it may serve as a text or reference book for
collegiate students of plant science who are seeking a proper foundation
upon which to build a scientific knowledge of how plants grow. The late
Dr. Charles E. Bessey, to whom I owe the beginning of my interest in plant
life, once said to me: "The trouble with our present knowledge of plant
science is that we have had very few chemists who knew any botany, and no
botanists who knew any chemistry." This may have been a slightly
exaggerated statement, even when it was made, several years ago. But it
indicated a very clear recognition by this eminent student of plants of the
need for a better knowledge of the chemistry of plant cell activities as a
proper foundation for a satisfactory knowledge of the course and results of
plant protoplasmic activities. It is hoped that the present work may
contribute something toward this desired end.

Second, the purpose of the writer will not have been fully accomplished
unless the book shall serve also as a stimulus to further study in a
fascinating field. Even the most casual perusal of many of its chapters
cannot fail to make clear how incomplete is our present knowledge of the
chemical changes by which the plant cell performs many of the processes
which result in the production of so many substances which are vital to the
comfort and pleasure of human life. Studies of the chemistry of animal life
have resulted in many discoveries of utmost importance to human life and
health. It requires no great stretch of the imagination to conceive that
similar studies of plant life might result in similar or even greater
benefit to human life, or society, since it is upon the results of plant
growth that we are dependent for most of our food, clothing, and fuel, as
well as for many of the luxuries of life.

The material presented in the book has been developed from a series of
lecture-notes which was used in