330 ANIMALS OF EGA. Chap. Y. 



given the striking case of the white and red-haired 

 Uakaris. If these two forms, which are considered by 

 the most eminent naturalists as distinct species, have 

 originated, as the facts of their distribution plainly tell 

 us they have, from one and the same stock, why may 

 not the various species of Lemurs, of Baboons, of Gib- 

 bons, and so forth, given the necessary amount of time 

 and climatal changes, have originated in the same way ? 

 And if we can thus account for the origin of the species 

 of one genus, on what grounds can we deny that the 

 genera of the same family, or the families of the same 

 order, have also proceeded from a common stock ? I 

 throw out these suggestions simply for the consideration 

 of thoughtful readers, but must add, that unless the 

 common origin, at least, of the species of a family be 

 admitted, the jDroblem of the distribution of monkeys 

 over the earth's surface must remain an inexplicable 

 mystery, whilst, if admitted*, a flood of light illuminates 

 the subject, and promises an early solution to honest 

 and patient investigation. These questions, also, show 

 how interesting and difficult are the problems which 

 Natural History, granted the right and ability of the 

 human mind to deal with them, has to solve. 



It is a suggestive fact that all the fossil monkeys 

 which have been found in Europe and America, belong 

 in each case to the types which are still peculiar to the 

 continent which they inhabit. The European fossils are 

 all of the Pithecidse family, the South American all 

 belong to the Cebidfe and Marmoset families. The 

 separation of the two continental masses (at least of 

 their warm zones) must therefore be of great geological 



