THE EFFECT OF CLIMATE AND WEATHER 329 



realize it when they tell how well the tropical climate agrees 

 with them. Yet for every individual who goes to the tropics 

 as a sojourner, a large number have thought of doing so but 

 have refrained because of limitations of health. Again, 

 among those who actually go to tropical countries a large 

 proportion leave after a few years because they do not like 

 the climate or because some member of their family 

 suffers from it. The few who remain permanently and 

 bring up families are in most cases persons of a peculiar type 

 of constitution which adapts them to the tropical climate. 

 By means of such selection for generation after generation 

 a strain of white people could probably be produced which 

 would be able to stand the tropical climate quite as well as 

 do any of the present tropical races. 



If the specific tropical diseases like malaria and hookworm 

 could be eliminated, the chances are that such people 

 could live in comparative health and comfort. They might 

 also maintain their present stage of civilization and go on to 

 a higher stage provided they could overcome the tremendous 

 handicap of contact with tropical races of lower standards. 

 There is not, however, the slightest reason to believe that 

 such tropical white people would change their climatic 

 optimum any more than the Javanese have changed theirs. 

 They would of course, be better adapted to tropical con- 

 ditions than are the ordinary white people of Europe and 

 the United States, but they would presumably still be 

 living in a climate which departs far from their optimum 

 and in which it is much harder to overcome the departures 

 than is the case in cooler climates. 



Perhaps some day some race will learn to guard itself 

 against high temperature, high humidity, and undue monot- 

 ony, but that is likely to prove far harder than to guard against 

 low temperature and undue dryness. Low temperature is 

 the easiest of all climatic handicaps to conquer, for fire, 

 houses, clothing and exercise are all methods of overcoming 

 its effects. Undue dryness too can be overcome to a con- 

 siderable extent by clothing which keeps the skin moist. 

 But high temperature, excessive humidity and excessive 

 monotony present a problem of far greater complexity 

 especially because those conditions predispose the individual 



