PREFACE 



A KNOWLEDGE of vegetable histology is the founda- 

 tion for the studies of microscopic pharmacognosy 

 and microanalysis of foods. It is so intimately related 

 to the studies of plant morphology and plant biology 

 that these subjects should be considered prerequisite 

 or should parallel the course in plant histology. 



This volume is intended for the beginner; and, 

 in many instances, details have been omitted in order 

 that the student may obtain a knowledge of general 

 principles without being confused by the minutiae 

 of the subject. Those intending to specialize in 

 vegetable histology, pharmacognosy and micro- 

 analysis of foods will find a wealth of detail in the refer- 

 ence books noted in the Appendix. 



The amount of laboratory work in vegetable 

 histology performed by the student is necessarily 

 governed by the amount of time at his disposal. 

 Lectures should be abridged if necessary, in order 

 that a greater amount of laboratory work may be 

 accomplished, for in no other branch of science is 

 the personal equation of such importance in the proper 

 interpretation of findings. Microscope equipment for 

 a class should be as nearly uniform as possible in order 

 that the complications due to different magnifications 

 may be eliminated. 



The writer would indeed be remiss if he did not 

 at this opportunity express his appreciation of the 



