66 THE ORIGIN OF SPECIES 



variety chanced io api>ear, selecting it, and so onward. 

 But the gardeners of the classical period, who cultivated 

 the best pears which they could procure, never thought 

 what splendid fruit we should eat; though we owe our 

 excellent fruit in some small degree to their having 

 naturally chosen and preserved the best varieties they 

 could anywhere find. 



A large amount of change, thus slowly and uncon- 

 sciously accumulated, explains, as I believe, the well- 

 known fact that in a number of cases we cannot recog- 

 nize, and therefore do not know, the wnld parent-stocks 

 of the plants which have been longest cultivated in our 

 flower and kitchen gardens. If it has taken centuries or 

 thousands of years to improve or modify most of our 

 plants up to their present standard of usefulness to man, 

 we can understand how it is that neither Australia, the 

 Cape of Good Hope, nor any other region inhabited by 

 quite uncivilized man, has afforded us a single plant 

 worth culture. It is not that these countries, so rich in 

 species, do not by a strange chance possess the aboriginal 

 stocks of any useful plants, but that the native plants 

 have not been improved by continued selection up to a 

 standard of perfection comparable with that acquired by 

 the plants in countries anciently civilized. 



In regard to the domestic animals kept by uncivilized 

 man, it should not be overlooked that they almost always 

 have to struggle for their own food, at least during 

 certain seasons. And in two countries very differently 

 circumstanced, individuals of the same species, having 

 slightly different constitutions or structure, would often 

 succeed better in the one country than in the other; and 

 thus by a process of "natural selection," as will hereafter 



