AN INTRODUCTION 



TO THE 



OSTEOLOGY OF THE MAMMALIA. 



CHAPTER I. 



CLASSIFICATION OF THE MAMMALIA. 



IT is not the object of the present work to enter in 

 detail into the subject of the Classification of the Mam- 

 malia ; but, as it will be necessary to refer frequently to the 

 principal subdivisions in which the various animals treated 

 of are arranged, a brief outline of the system adopted will be 

 necessary. 



A perfect arrangement of any group of animals can only 

 be attained simultaneously with a perfect knowledge of their 

 structure and life-history. We are still so far from this 

 that any classification now advanced must be regarded as 

 provisional, and merely representing our present state of 

 knowledge. Moreover, as naturalists will estimate differ- 

 ently the importance to be attached to different structural 

 modifications as indicative of affinity, it must be long before 

 there will be any general agreement upon this subject 



