4 THE DESCENT OF THE PRIMATES 



bility of studying the complete anatomy, or 

 the development, we yet dispose of skeletons, 

 teeth, shells, leaves, portions of bark, etc., by 

 which we are guided in determining their rela- 

 tion either to living beings or to other fossil 

 remains. 



In no country has the discovery of important 

 fossils advanced at such a rapid rate as in 

 America, both north and south of the equator. 

 And it is to the undaunted zeal of your explorers, 

 and to the keen discrimination of }our palaeon- 

 tologists, such as Leidy, Cope, Marsh, Scott, 

 Osborn, and others, that we owe most valuable 

 material, which is at the same time the firmest 

 foundation upon which Evolution can be es- 

 tablished. 



It is just twenty years ago that Huxley, in the 

 three famous lectures which he delivered at New 

 York, called this " the demonstrative evidence of 

 Evolution." And in those twenty years the 

 accumulation of new evidence, all tending in the 

 same direction, has never ceased. It has been 

 especially voluminous with respect to reptiles and 

 mammals. In this latter class new orders have 

 sprung up, new genera have had to be created by 

 the dozen, and certain skeletons have come to 

 light which must have belonged to what have 



