56 HEREDITY AND CHRISTIAN PROBLEMS 



down the generations. There are amazing differ- 

 ences between the Esquimau, gorging himself with 

 whale-blubber, and the refined and subtle thinkers 

 among the Brahmins in India. Italians and Afri- 

 cans carry within themselves something of the 

 heat of southern and tropical suns. Germans 

 and Swedes, like their climate, are cooler. There 

 is gradually accomplished a physical change in 

 those who live in the tropics. Heat makes exer- 

 tion difficult; hence the intense and continued 

 activity of northern people is seldom known in 

 the south. If a dweller among the tropics re- 

 moves to a northern zone, in due time his physi- 

 cal constitution, and with it his moral also, is 

 modified. In other words, life adjusts itself to 

 environment. 



One of the most curious of the illustrations of 

 the effect of climate upon bodily constitution is 

 that of the Ouechua Indians, of the lofty plains 

 of Peru. From the constant inhalation of the 

 air at a very high altitude their chests and lungs 

 gradually became extraordinarily developed, the 

 cells being larger and more numerous than 

 among Europeans. " Mr. D. Forbes," says Dar- 

 win, " carefully measured many Aymaras, an 

 allied race living at a height of between ten and 

 fifteen thousand feet, and he informs me that 



