^ DEPARTMENT 



OF 

 MATERIA MEDICA 



PREFACE TO THE FIRST EDITION 



This little book is intended to serve as a guide for beginners 

 in the study of plant tissues with the microscope, with supple- 

 mental instruction from the teacher. 



The greater portion deals with the tissues and their arrange- 

 ment in the higher plants, but it was thought advisable to intro- 

 duce a few lessons on the simplest plants, namely, some of those 

 of the Thallophyte series, not only on account of their great 

 importance in the life economy, but also to show the gradual 

 increase in complexity of structure in passing from the ex- 

 tremely simple and minute plants of the Thallophyte series to 

 the complicated highly organized members of the Phanerogams, 

 thus giving the student a complete view of the structure and 

 characteristics of the whole range of the vegetable kingdom. 



The knowledge of the tissues of the higher plants gained in 

 this book, which maybe designated as the Junior Course, will find 

 practical application in the recognition of official vegetable 

 drugs, the detection of adulterations, the study of ground drugs 

 and their adulterations. This branch of study is called 

 Pharmacognosy and is daily increasing in importance. 



The opening pages deal with a few physical principles and a 

 description and explanation of the action of a compound micro- 

 scope, its defects, the requirements of a good instrument, etc. 

 The author is well aware that it is possible for one to work 

 with a microscope without understanding its action, just as a 

 man may know how to start and stop an engine without know- 

 ing anything of its mechanism and theory of action. But it 

 needs no argument to convince anyone that a student who 

 knows the theory and structure of a microscope is far better 



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