188 THE DESCENT OF MAN. [Part I. 



Family, or even Order. But in this case it is almost cer- 

 tain that the third line would still retain through inheri- 

 tance numerous small points of resemblance with the 

 other tw T o lines. Here, then, would occur the difficulty, at 

 present insoluble, how much weight we ought to assign in 

 our classifications to strongly-marked differences in some 

 few points — that is, to the amount of modification under- 

 gone ; and how much to close resemblance in numerous 

 unimportant points, as indicating the lines of descent or 

 genealogy. The former alternative is the most obvious, 

 and perhaps the safest, though the latter appears the most 

 correct as giving a truly natural classification. 



To form a judgment on this head, with reference to 

 man we must glance at the classification of the Simiadse. 

 This family is divided by almost all naturalists into the 

 Catarhine group, or Old World monkeys, all of which are 

 characterized (as their name expresses) Iby the peculiar 

 structure of their nostrils and by having four premolars 

 in each jaw ; and into the Platyrhine group or New World 

 monkeys (including, two very distinct sub-groups), all of 

 which are characterized by differently-constructed nostrils 

 and by having six premolars in each jaw. Some other 

 . small differences might be mentioned. Now man unques- 

 tionably belongs in his dentition, in the structure of his 

 nostrils, and some other respects, to the Catarhine or Old 

 World division ; nor does he resemble the Platyrhines 

 more closely than the Catarhines in any characters, ex- 

 cepting in a few of not much importance and apparently 

 of an adaptive nature. Therefore it would be against all 

 probability to suppose that some ancient New World 

 species had varied, and had thus produced a "man-like 

 creature with all the distinctive characters proper to the 

 Old World division ; losing at the same time all its own 

 distinctive characters. There can consequently hardly be 

 a doubt that man is an offshoot from the Old World Sim- 



