54 THE DESCENT OF MAN. 



the pressure of the brain in a new direction.*' I have shown that 

 with long-eared rabbits even so trifling a cause as the lopping for- 

 ward 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 ob- 

 servations on domestic rabbits, some kinds of which have become 

 very much larger than the wild animal, whilst others have re- 

 tained nearly the same size, but in both oases 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 large domestic kind, the former was 3.15 and the latter 

 4.3 inches in length.'^ One of the most marked distinctions in dif- 

 ferent 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 in- 

 "cline more to brachycephaly, and tall men to dolichocephaly;"*" 

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

 rabbits, all of which have elongated skulls, or are dolichocephalic. 



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 ani- 

 mals. 



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 through the water; 

 nor would it be injurious to them from the loss of warmth, as 

 the species, which inhabit the colder regions, are protected by a 

 thick layer of blubber, serving the same purpose as the fur of seals 



" Schaaffhausen gives from Blumenbach and Busch, the oases of the 

 spasms and cicatrix, in 'Anthropolog. Review,' Oct., 1868, p. 420. Dr. 

 Jarrold ('Aiithropologia,' 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 shoemaker, where the head is habitually 

 held forward, the forehead becomes more rounded and prominent. 



80 'Variation of Animals,' &c., vol. i. p. 117, on the elongation of the 

 skull; p. 119, on the effect of the lopping of one ear. 



80 Quoted by Schaaffhausen, in 'Anthropolog. Review,' Oct., 1868, 

 p. 43* 



