38 SELECTION BY MAN. Chap. I. 



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 uncivilised man, has afforded us 

 a single plant worth culture. It is not that these coun- 

 tries, 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 se« 

 lection up to a standard of perfection comparable with 

 that given to the plants in countries anciently civilised. 



In regard to the domestic animals kept by uncivilised 

 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 dif- 

 ferently 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 be more fully explained, two sub-breeds 

 might be formed. This, perhaps, partly explains what 

 has been remarked by some authors, namely, that the 

 varieties kept by savages have more of the character of 

 species than the varieties kept in civilised countries. 



On the view here given of the all-important part which 

 selection by man has played, it becomes at once obvious, 

 how it is that our domestic races show adaptation in their 

 structure or in their habits to man's wants or fancies. 

 We can, I think, further understand the frequently 

 abnormal character of our domestic races, and likewise 

 their differences being so great in external characters 

 and relatively so slight in internal parts or organs. 

 Man can hardly select, or only with much difficulty, any 

 deviation of structure excepting such as is externally 

 visible ; and indeed he rarely cares for what is internal. 

 He can never act by selection, excepting on variations 



