PART II. 



Genetic Relations of the Mammalian Orders. 



Contents . 



Page 

 Introduction. Remarks on the Principles of Research in Mammalian Phy- 



logeny 105 



Chapter I. The Origin of Mammals and the Problem of the Mammalian Ossi- 



cula Auditus 113 



Chapter II. Genetic Relations of the Monotremata 144 



Chapter III. Genetic Relations of the INIesozoic Orders Protodonta Multi- 



tuberculata, Triconodonta and Trituberculata 162 



Chapter IV. Genetic Relations of the Marsupialia 197 



Chapter V. Genetic Relations of the Insectivora and Tillodontia . . . • 231 

 Chapter VI. Genetic Relations of the Carnivora (Creodonta, Fissipedia, Pinni- 



pedia) 294 



Chapter VII. Genetic Relations of the Dermoptera, Chiroptera and Primates 315 



Chapter VIII. Genetic Relations of the Rodents and Edentates 323 



Chapter IX. Genetic Relations of the Ungulata and Sirenia 342 



Chapter X. Genetic Relations of the Cetacea 411 



Chapter XI. Osteological Miscellanies 420 



Chapter XII. Conclusions. The "Meseutheria" and "C^neutheria." Super- 

 ordinal and Ordinal Classification of the Mammalia 457 



Selected references 469 



INTRODUCTION. 



Remarks on the Principles of Research in ^Mammalian Phylogeny. 



Difficulty of reaching correct phi/Iogenetic results. — The greatest stum- 

 bling blocks of the phylogenist lie: first in the difficulty of distinguishing 

 between primitive and specialized characters, secondly in the tendency 

 to assume relationship betAveen two given forms on the basis of resemblances 

 that may have been brought about by either parallel or convergent evolution. 

 From the earliest times comparative anatomists and paleeontologists have 

 repeatedly misread the record, mistaken analogy for homology, and inter- 

 changed descendants and ancestors. 



105 



