THE DESCENT OR OBIOIN OF MAN 255 



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- 

 colored Brahmin, 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 

 Hindus." Whether a heterogeneous people, such as the 

 inhabitants 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 genera- 

 tions, we may infer that the free intercrossing of a hetero- 

 geneous 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 homo- 

 geneous, 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 color 

 of the skin is the most conspicuous and one of the best 

 marked. It was formerly thought that differences of this 

 kind could be accounted for by long exposure to different 

 climates; but Pallas first showed that this is not tenable, 

 and he has since been followed by almost all anthropolo- 

 gists." This view has been rejected chiefly because the dis- 

 tribution of the variously colored races, most of whom must 

 have long inhabited their present homes, does not coincide 



«> "Annals of Rural Bengal," 1868, p. 134. 



" "The Variation of Animals and Plants under Domestication," vol. ii. 

 p. 95. 



" Pallas, "Act. Acad. St. Petersburg," ItSO, part ii. p. 69. He was fol- 

 lowed by Eudolphi, in his "Beytrage zur Anthropologie, " 1812. An excellent 

 summary of the eyidence is given by Godron, "De I'Bsp^ce," 1859, vol. ii. 

 p. 246, etc. 



