Preface to the Third Edition 
The author has first endeavored to present in a clear, syste- 
matic way those fundamental principles of structural and 
taxonomic botany which serve as a key to the approach of 
pharmacognic problems. But he has not been unmindful that 
the use of the work has extended to academic institutions and, © 
so, in this edition, has broadened the scope of the former text. 
To this end about ninety additional pages of subject matter 
have been introduced. Several old cuts have been removed. 
Forty-three new ones have been inserted. Hypothetical dis- 
cussions have been avoided which saves time for the reader. 
The arrangement and plan of the chapters are similar to that 
of the former edition, in order to adapt the work to several 
methods of approach. Chapter I on “Fundamental Considera- 
tions” has been augmented by treatises on Botanical Nomen- 
clature, Paraffine and Celloidin Imbedding, Sectioning, Staining 
and Mounting, Microtomes and other information dealing with 
the preparation of materials for microscopic examination. 
Ten pages have been added to Chapter V on Cytology. 
Under ‘‘Protoplasm and its Properties,” six pages have been 
written on the subject of Irritability and Irritable Reactions. 
Under ‘“‘Non-Protoplasmic Cell Contents” several additional 
commercial starches are discussed and two original plates on 
starch grains added. Additional cuts on Collenchyma, Stone 
Cells, Sclerenchyma Fibers, Trichomes and Fibrovascular 
Bundles have been inserted in Chapter VI. 
Nine additional pages of subject matter and illustrations have 
been added to Chapter VII. Original figures of all of the 
important types of fruits appear here for the first time. 
Chapter VIII on ““Taxonomy”’ has been increased by seven 
pages of new data, and the whole former text carefully revised. 
Chapter IX on ‘‘Ecology”’ has been newly introduced as has 
also a Glossary of Botanical Terms. The index has been so 
planned as to make the information contained in this book 
_ readily accessible. 
To the authors of works from which cuts were borrowed the 
writer’s thanks are due. Ev. X- 
XV 
