232 THE DESCENT OF MAN. [Part I. 



wide diffusion by various indigenous tribes. When two 

 races in close contact cross, the first result is a heterogene- 

 ous mixture : thus Mr. Hunter, in describing the Santali 

 or hill-tribes of India, says that hundreds of impercep- 

 tible gradations may be traced "from the black, squat 

 tribes of the mountains to the tall olive-colored Bramin, 

 with his intellectual brow, calm eyes, and high but nar- 

 row head ; " so that it is necessary in courts of justice to 

 ask the witnesses whether they are Santalis or Hindoos. 37 

 Whether a heterogeneous people, such as the inhabitants 

 of some of the Polynesian islands, formed by the cross- 

 ing 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 crossed breed can certainly, in the course of a few gen- 

 erations, be fixed and made uniform by careful selection, 38 

 we may infer that the free and prolonged intercrossing 

 during many generations of a heterogeneous mixture 

 would supply the place of selection, and overcome any 

 tendency to reversion, so that a crossed race would ulti- 

 mately become homogeneous, though it might not par- 

 take in an equal degree of the characters of the two par- 

 ent-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. Differences of this kind, it was formerly 

 thought, could be accounted for by lo^g exposure under 

 different climates-; but Pallas first showed that this view 

 is not tenable, and he has been followed by almost all an- 

 thropologists. 39 The view has been rejected chiefly be- 



37 'The Annals of Rural Bengal,' 1868, p. 134. 



38 ' The Variation of Animals and Plants under Domestication,' vol. 

 li. p. 95. 



89 Pallas, 'Act. Acad. St. Petersburg,' 1780, part ii. p. 69. He was 

 followed by Rudolphi, in his ' Beytrage zur Anthropologic,' 1812. An 



