56 



The Descent of Man. 



Part 1. 



apparently by the pressure of the brain in a new direction. 84 

 I have shewn that with long-eared rabbits even so trifling a cause 

 as the lopping forward of one ear drags forward almost every 

 bone of the skull on that side ; so that the bones on the opposite 

 side no longer strictly correspond. Lastly, if any animal were 

 to increase or diminish much in general size, without any change 

 in its mental powers, or if the mental powers were to be much 

 increased or diminished, without any great change in the size of 

 the body, the shape of the skull would almost certainly be 

 altered. I infer this from my observations on domestic rabbits, 

 some kinds of which have become very much larger than the 

 wild animal, whilst others have retained nearly the same size, 

 but in both cases the brain has been much reduced relatively to 

 the size of the body. Now I was at first much surprised on 

 finding that in all these rabbits the skull had become elongated 

 or dolichocephalic ; for instance, of two skulls of nearly equal 

 breadth, the one from a wild rabbit and the other from a larce 

 domestic kind, the former was 3*15 and the latter 4/3 inches in 

 length. 85 One of the most marked distinctions in. different races 

 of men is that the skull in some is elongated, and in others 

 rounded; and here the explanation suggested by the case of the 

 rabbits may hold good; for Welcker finds that short "men incline 

 more " to brachycephaly, and tall men to dolichocephaly ;" 86 and 

 tall men may be compared with the larger and longer-bodied 

 rabbits, all of which have elongated skulls, or are dolicho- 

 cephalic. 



From these several facts we can understand, to a certain 

 extent, the means by which the great size and more or less 

 rounded form of the skull have been acquired by man ; and these 

 are characters eminently distinctive of him in comparison with 

 the lower animals. 



Another most conspicuous difference between man and the 

 lower animals is the nakedness of his skin. "Whales and 

 porpoises (Cetacea), dugongs (Sirenia) and the hippopotamus are 

 naked ; and this may be advantageous to them for gliding 



84 Schaaffhausen gives from Blu- 

 menbach and Busch, the cases of the 

 spasms and cicatrix, in 'Anthro- 

 polog. Review,' Oct. 1868, p. 420. 

 Dr. Jarrold (' Anthropologia,' 1808, 

 pp. 115, 116) adduces from Camper 

 and from his own observations, cases 

 of the modification of the skull from 

 the head being fixed in an unnatural 

 position. He believes that in cer- 

 tain trades, such as that of a shoe- 



maker, where the head is habitually 

 held forward, the forehead becomes 

 more rounded and prominent. 



85 ' Variation of Animals.' &o., 

 vol. i. p. 117, on the elongation of 

 the skull; p. 119, on the effect of 

 the lopping of one ear. 



86 Quote 1 by Schaaffhausen, ia 

 ' Anthropolog. Review,' Oct. I8fi8, 

 p. 419. 



