War Results in Negative Selection 281 



When civilized nations come into contact with bar- 

 barians the struggle is short, except where a deadly 

 climate gives its aid to the native race. Of the causes 

 which lead to the victory of civilized nations, some 

 are plain and simple, others complex and obscure. 

 We can see that the cultivation of the land will be 

 fatal in many ways to savages, for they cannot, or 

 will not, change their habits. New diseases and 

 vices have in some cases proved highly destructive; 

 and it appears that a new disease often causes much 

 death, until those who are most susceptible to its 

 destructive influence are gradually weeded out; and 

 so it may be with the evil effects from spirituous 

 liquors, as well as with the unconquerably strong 

 taste for them shown by so many savages. It further 

 appears, mysterious as is the fact, that the first meet- 

 ing of distinct and separated people generates dis- 

 ease. Mr. Sproat, who in Vancouver Island closely 

 attended to the subject of extinction, believed that 

 changed habits of life, consequent on the advent of 

 Europeans, induces much ill-health. He lays, also, 

 great stress on the apparently trifling cause that the 

 natives become "bewildered and dull by the new life 

 around them; they lose the motives for exertion, and 

 get no new ones in their place. "^ 



After surveying the whole field of the causes, 

 Darwin returns to the factor of a lessened fer- 

 tility of women which follows changed condi- 

 tions among barbarous peoples not able to adapt 

 themselves to the new civilization, and he de- 

 votes a large part of his chapter on "The 



' The Descent of Man, pp. 198-99. 



