PLACE OF ANTHROPOIDS IN NATURE. 287 



Macacus pliocenus from Essex is closely related to 

 Macacus sinicus. Fossil apes have also been ob- 

 served in America. Protopithecus was a very large 

 animal, related to Mijcetes. Another fossil species, 

 found in South America {Laopithecus), must have 

 been closely related to man. This latter fact is 

 the more remarkable, since it has generally been 

 assumed, and indeed with reason, that there is a 

 marked division between the apes of the Old and 

 New Worlds. 



The species now f«>und in tropical America of 

 the silky apes {Hapale), the Sahui (Jacchus), the 

 leaping apes (Gallithrix), the bellowing apes (Mij- 

 cetes), and the rolling apes (Cehus), were already 

 represented in the diluvial period of that continent. 

 It does not appear that any extensive generic diffu- 

 sion of apes has taken place since that period. It 

 is otherwise with the development of species, which 

 seems, at any rate to a partial extent, to have 

 occurred late. This may be inferred from the 

 physical characteristics of gorillas and chimpanzees, 

 which, with all their differences, have much in com- 

 mon with each other. In the fourth chapter we 

 have described forms of apes lying between the 

 gorilla and the chimpanzee, and it seems possible 

 that these are a reversion to one or the other form. 

 The numerous varieties of form among anthropoids 

 point to a continuance of the process of severance 

 in this family of apes, and little more than an 

 isolating influence is needed to produce the gradual 

 conversion of vai'ieties into constant species. 



On account of their external bodily character- 



