192 The Descent of Man. Pabt L 



later lead to extinot^'on , the end, in most cases, being promptly 

 determined by the inroads of conquering tribes. 



On tlie Formation of the Races of Man. — In some cases the 

 crossing of distinct races has led to the formation of a new race. 

 Tlie singular fact that Europeans and Hindoos, who belong to 

 the same Aryan stock, and speak a language fundamentally the 

 same, differ widely in appearance, whilst Europeans differ but 

 little from Jews, who belong to the Semitic stock, and speak 

 quite another language, has been accounted for by Broca,'"' 

 through certain Aryan branches having been largely crossed 

 by indigenous tribes during their wide diffusion. When two 

 races in close contact cross, the first result is a heterogeneous 

 mixture : thus Mr. Hunter, in describing the Santali or hill-tribes 

 of India, says that hundreds of imperceptible gradations may be 

 traced " from the black, squat tribes of the mountains to the tall 

 " olive-coloured Brahman, with his intellectual brow, calm eyes, 

 "and high but narrow head;" so that it is necessary in courts 

 of justice to ask the witnesses whether they are Santalis or 

 Hindoos.'* Whether a heterogeneous people, such as the inhabi- 

 tants of some of the Polynesian islands, formed by the crossing 

 of two distinct races, with few or no pure members left, would 

 ever become homogeneous, is not known from direct evidence. 

 But as with our domesticated animals, a cross-breed can certainly 

 be fixed and made uniform by careful selection*' in the course of 

 a few generations, we may infer that the free intercrossing of a 

 heterogeneous mixture during a long descent would supply the 

 place of selection, and overcome any tendency to reversion ; so 

 that the crossed race would ultimately become homogeneous, 

 though it might not partake in an equal degree of the characters 

 of the two parent-races. 



Of all the differences between the races of man, the colour of 

 the skin is the most conspicuous and one of the best marked. It 

 viis formerly thought that differences of this kind could be 

 accounted for by long exposure to different climates; but 

 Pallas first shewed that this is not tenable, aud he has since been 

 followed by almost all anthropologists.*^ This view has been 

 rejected chiefly because the distribution of the variously 

 coloured races, most of whom must have long inhabited their 



-■" 'On Anthropology,' transla- '^ Palks, ' Act. Acad. St. Peter.s- 



tion ' Auihropolog. Review,' Jan. burg,' 1780, part ii. p. 69. He was 



1868, p. 38. followed by Rudolphi, in his ' Bcy- 



^'^ ' The Annals cf Rural Bengal,* trage zur Anthropologie,' 1812. 



1868, p. 134. An excellent summary of the ovi- 



^' ' The Varia^'on of Animals and dence is given by Godron, * iJe 



PI ints under Do'.nesticatiun, vol. ii. I'Kspiice,' 1859, vol. ii. p. 'J-16, &i'. 



p. as. 



