CHAPTER XXVII 



THE MIGRATION OF TERRESTRIAL VERTEBRATES 



Importance of these migrations Migrations in Primary times Pal?eo- 

 geograpliical sketch of the Primary and Secondary Articulates 

 Migrations of Secondary times Evolution of the Continents 

 Migrations of Tertiary Mammals. 



EVEN more than the marine animals, the terrestrial, 

 and especially the Vertebrates, whether Amphibians, 

 Reptiles, or Mammals, furnish exact documents 

 interesting for the study of geological migrations. 

 This is mainly due to their limited means of loco- 

 motion, which are closely connected with the con- 

 tinuity of the continental base on which they live. 

 It may even be asserted that the migrations of 

 terrestrial Vertebrates, when founded on sure 

 evidence, constitutes the firmest foundation and 

 the clearest demonstration of the palseogeographical 

 sketches founded generally on the distribution of 

 marine deposits. 



By reason of the importance of these facts, I 

 think it well to enter into a few details on the 

 subject, which as yet has been somewhat slightly 

 treated by palaeontologists, and we will proceed to 

 study, one after the other, the migrations of the 

 Primary, Secondary, and Tertiary epochs. 



293 



