14 A NEW THEORY OF EVOLUTION. 



of men whose profit or loss depends on the 

 truth of the inferences they draw from simple 

 and repeated observations ; and when we 

 find that the inferences arrived at, and 

 handed down from generation to genera- 

 tion of those deeply interested observers, 

 have become an unshakable conviction, we 

 may accept it without hesitation." 



Now, evidence of this character is pro- 

 vided by the uniform experience of skilful 

 breeders of all domestic animals ; but we 

 shall deal only with the breeding of cattle, 

 because the various races are closely allied, 

 their habits and appearance are generally 

 known, their mating is closely controlled, 

 their pedigrees are well authenticated, and 

 numerous families or herds are bred under 

 different conditions throughout the country. 

 Cattle-breeding, in short, provides wider and 

 more trustworthy results than can be had of 

 any other domestic race. 



Theoretically the object of selective breed- 

 ing is to develop the fullest expression of 

 the type of the race, and its practice consists 

 in carefully selecting for breeding purposes 

 animals that, in the breeder's judgment, 

 possess the best expression of the type ; and 

 so again with their progeny. 



The animals selected are carefully pro- 



