122 



THE GENESIS OF SPECIES. 



[CHAP. 



cariensis) was till lately considered to be allied to the squir- 

 rels, and was often classed with, them in the rodent order, 

 principally on account of its dentition ; at the same time 

 that its affinities to the lemurs and apes were admitted. 

 The thorough investigation into its anatomy which has 

 now been made demonstrates that it has no more essential 

 affinity to rodents than any other lemurine creature has. 



THE AYE-AYE. 



Bats were, by the earliest observers, naturally supposed 

 to have a close relationship to birds, and cetaceans to 

 fishes. It is almost superfluous to observe that all now 

 agree that these mammals make not even an approach to 

 either one or other of the two inferior classes. 



In the same way it has been till recently supposed that 

 those extinct flying saurians, the pterodactyles, had an 

 affinity with birds more marked than any other known 

 animals. Now, however, as has been already said, it is 

 contended that not only had they no such close affinity, 

 but that other extinct reptiles had a far closer one. 



