VI PREFACE 



material presented has been selected for the light it throws on the phylo- 

 genesis (racial history) and the physiology of the human body. 



The present text has been written to meet the needs of students in 

 semester courses in comparative anatomy. It is an abbreviation of the 

 Comparative Anatomy written by the same authors and published in 

 1936. In the condensation, however, no material essential to the proper 

 understanding of the physiology and phylogenesis of the human body 

 has been omitted. Due acknowledgment of assistance in the preparation 

 of the book has been made in the earlier work, to which the reader is 

 referred. 



