vi MAMMARY APPARATUS OF THE MAMMALIA 



course of evolution to the essential secretory 

 part of the mammary system, the milk glands, 

 with which alone the primitive Mammal was 

 provided, just as is the existing Platypus. 

 Professor Bresslau, moreover, on the basis of 

 his detailed developmental observations, has 

 been led to most interesting and suggestive 

 conclusions as to the first origin of the mam- 

 mary organs and their evolutionary history in 

 the chief subdivisions of the Mammals. 



His principal memoirs on this subject are to 

 be found in Dr. R. Semon's " Forschungsreisen . 

 im Australien und dem Malayischen Archipel " 

 (Bd. 4, Lfg. 6, 1907, and Lfg. 7, 1912), a 

 monumental work which, however, is little 

 known outside the ranks of the specialist. 

 The present volume provides the English- 

 speaking student with a resume of these 

 memoirs, all the more valuable since it has 

 been prepared by their author himself. It 

 should appeal to all who are interested in the 

 fascinating problems of Mammalian evolution. 



It is only fair to Professor Bresslau to add 

 that he has had no opportunity of seeing the 

 proofs, the correction of which was undertaken 

 by the publishers. 



JAMES P. HILL 



FeiriMry, 1920. 



