PREFACE TO THE FIFTH EDITION 



The very gratifying approval which the previous editions of 

 the Text-book received has made it seem unwise to attempt any 

 change in the general plan and scope of the work as outlined in the 

 preface to the first edition. The text has been thoroughly revised, 

 some parts of it rewritten. Some figures have been added, for 

 which the writer wishes to acknowledge his obligations. To Prof. 

 H. von W. Schulte and to Prof. A. M. Miller the writer has been 

 indebted for many valuable criticisms and suggestions. The 

 chapter on the nervous system, which was rewritten by Dr. Oliver 

 S. Strong for the third edition and revised by him for the fourth 

 edition, remains unchanged. For Dr. Strong's careful and pains- 

 taking work on this chapter, for his thoroughly original treatment 

 of his subject, and for the original drawings and photographs in this 

 chapter, the author wishes again to express his most grateful appre- 

 ciation. Dr. Strong again desires to acknowledge his indebtedness 

 to Dr. Adolf Meyer for many ideas and terms found valuable in the 

 preparation of the chapter on the nervous system. 



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