Environment. 69 



to wear a hairy coat: but on moving up into the 

 high plains of the Andes, and the rarefied and chilly 

 atmosphere there, they change their mind, and take 

 on a kind of coarse wool. Or, to illustrate the 

 same process of adaptation in man himself, both 

 naturally and artificially, I will cite a note of M. 

 Flinders Petrie, which you may take for what it is 

 worth. It is amusing, but suggestive: " We all 

 know how translucent flesh is to strong light, and 

 it can hardly be doubted that the rays of the trop- 

 ical sun would light up a white man's inside con- 

 siderably; whereas black skin would stop out the 

 solar energy of light, heat and chemical rays effect- 

 ually. Skin heat is of no importance, as perspira- 

 tion can always keep that down. May not the oil- 

 ing of the skin in hot countries be partly to make 

 it reflective, so that it should absorb less heat? 

 And may not the regard that white races have for 

 clothing be partly for the purpose of keeping the 

 insides of their bodies sufficiently in the dark?" 



79. To return to our question, I say that an ac- 

 quired or second nature will be the result of all the 

 combined influences, which act in a given environ- 

 ment upon our radical human nature. Ordinarily 

 speaking, too, only one particular race will result 

 as the final outcome of perfect naturalization in 

 given conditions of existence. 



80. Here, then, the character of race is seen to 

 be made up of two elements, the fundamental or 

 radical nature common to all, and the acquired or 



