140 MAN AND THE LOWER ANIMALS. n 



So far as cerebral structure goes, therefore, it 

 is clear that Man differs less from the Chimpanzee 

 or the Orang, than these do even from the Mon- 

 keys, and that the difference between the brains 

 of the Chimpanzee and of Man is almost insig- 

 nificant, when compared with that between the 

 Chimpanzee brain and that of a Lemur. 



It must not be overlooked, however, that there 

 is a very striking difference in absolute mass and 

 weight between the lowest human brain and that 

 of the highest ape — a difference which is all the 

 more remarkable when we recollect that a full- 

 grown Gorilla is probably pretty nearly twice as 

 heavy as a Bosjesman, or as many an European 

 woman. It may be doubted whether a healthy 

 human adult brain ever weighed less than thirty- 

 one or two ounces, or that the heaviest Gorilla brain 

 has exceeded twenty ounces. 



This is a very noteworthy circumstance, and 

 doubtless will one day help to furnish an explana- 

 tion of the great gulf which intervenes between the 

 lowest man and the highest ape in intellectual 

 power; * but it has little systematic value, for the 



* I say help to furnish: for I by no means believe that 

 it was any original difference of cerebral quality, or quan- 

 tity, which caused that divergence between the human 

 and the pithecoid stirpes, which has ended in the present 

 enormous gulf between them. It is no doubt perfectly 

 true, in a certain sense, that all difference of function is a 

 result of difference of structure; or, in other words, of 

 difference in the combination of the primary molecular 

 forces of living substance; and, starting from this unde- 



