2 INTRODUCTION 



this is true, but the number of structures displayed by this method 

 is very limited, and even those made visible are not shown in 

 great detail. Furthermore, such methods present to our senses 

 only structures as they exist in the presence of some more or less 

 non-toxic dyestuff : not as they are in their natural environment. 

 After saying so much as to the deficiencies of microscopy, we can 

 approach the subject of the present volume in a humble sj^irit, 

 admiring the persistence that has given such admirable results. 



No attempt has been made to convert this chapter into a work of 

 reference : nothing more has been tried than to give an impression 

 of the present position of certain aspects of human histology in 

 their present state of development. For this reason persons are 

 scarcely mentioned, because, as the book is not intended for the 

 professional histologist, coherence of the account appeared to be 

 more important than completeness of the documentation. 



