THE RACES OF MAN, 223 



and blisters a white skin, does not injure a black one at all; 

 and, as he adds, this is not due to habit in the individual, 

 for children only six or eight months old are often carried 

 about naked, and are not affected. I have been assured by 

 a medical man that some years ago during each summer, 

 but not during the winter, his hands became marked with 

 light brown patches, like, although larger than freckles, 

 and that these patches were never affected by sun-burning, 

 while the white parts of his skin have on several occasions 

 been much inflamed and blistered. With the lower ani- 

 mals there is, also, a constitutional difference in liability to 

 the action of the sun between those parts of the skin 

 clothed with white hair and other parts.* Whether the 

 saving of the skin from being thus burned is of sufficient 

 importance to account for a dark tint having been gradually 

 acquired by man through natural selection I am unable to 

 judge. If it be so, we should have to assume that the 

 natives of tropical America have lived there for a much 

 shoiler time than the negroes in Africa, or the Papuans in 

 the southern parts of the Malay Archipelago, just as the 

 lighter-colored Hindoos have resided in India for a shorter 

 time than the darker aborigines of the central and southern 

 parts of the peninsula. 



Although with our present knowledge we cannot account 

 for the differences of color in the races of man, through 

 any advantage thus gained, or from the direct action of 

 climate; yet we must not quite ignore the latter agency, 

 for there is good reason to believe that some inherited effect 

 is thus produced, f 



We have seen in the second chapter that the conditions 

 of life affect the development of the bodily frame in a 

 direct manner, and that the effects are transmitted. Thus, 

 as is generally admitted, the European settlers in the 

 United States undergo a slight but extraordinary rapid 



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

 pp. 336, 337. 



f See, for instance, Quatrefages (" Revue des Cours Scientifiques," 

 Oct. 10, 1868, p. 724) on the effects of residence in Abyssinia and 

 Arabia, and other analogous cases. Dr. Rolle (" Der Mensch, seine 

 Abstammung," etc., 1865, s. 99) states, on the authority of Khanikof, 

 that the greater number of German families settled in Georgia have 

 acquired in the course of two generations dark hair and eyes. Mr. 

 D. Forbes informs me that the Quichuas in the Andes vary greatly in 

 color, according to the position of the valleys inhabited by them. 



