Chap. VII. THE EACES OF MAN. 247 



about the hot forests of the interior and live chiefly on 

 vegetable productions ; yet these tribes resemble each 

 other so closely that the Fuegians on board the " Beagle" 

 were mistaken by some Brazilians for Botocudos. The 

 Botocudos again, as well as the other inhabitants of 

 tropical America, are wholly different from the Negroes 

 who inhabit the opposite shores of the Atlantic, are 

 exposed to a nearly similar climate, and follow nearly 

 the same habits of life. 



Nor can the differences between the races of man be 

 accounted for, except to a quite insignificant degree, by 

 the inherited effects of the increased or decreased use of 

 parts. Men who habitually live in canoes, may have 

 their legs somewhat stunted ; those who inhabit lofty 

 regions have their chests enlarged ; and those who con- 

 stantly use certain sense-organs have the cavities in 

 which they are lodged somewhat increased in size, and 

 their features consequently a little modified. With 

 civilised nations, the reduced size of the jaws from 

 lessened use, the habitual play of different muscles 

 serving to express different emotions, and the increased 

 size of the brain from greater intellectual activity, have 

 together produced a considerable effect on their general 

 appearance in comparison with savages. 52 It is also 

 possible that increased bodily stature, with no corre- 

 sponding increase in the size of the brain, may have 

 given to some races (judging from the previously ad- 

 duced cases of the rabbits) an elongated skull of the 

 dolichocephalic type. 



Lastly, the little-understood principle of correlation 

 will almost certainly have come into action, as in the 

 case of great muscular development and strongly pro- 



52 See Prof. Schaaffhausen, translat. in 'Anthropological Keview,' 

 Oct. 1868, p. 429. 



