286 THE BREEDING OF ANIMALS 



The origin of the peculiar characters which are valuable 

 in the domesticated animal is believed to have come 

 about through a similar process of selection but with this 

 difference : Man has introduced methodical selection by 

 which all animals are preserved, not only those suited 

 to their particular environment but also and chiefly those 

 which possess characteristics that are valuable to man. 

 Many complex and difficult questions have arisen in con- 

 nection with the improvement of the domesticated ani- 

 mals involving the most difficult problems of inheritance. 



271. Methodical selection. The selection practiced 

 by man is known as methodical selection. Animals are 

 selected because of their peculiar fitness for special pur- 

 poses. The powerful, heavy draft-horse is the result of 

 generations of careful selection and breeding in an effort 

 to produce an animal that can pull heavy loads. 



In the same way but with a different standard of selec- 

 tion, the speed horse has developed an extraordinary 

 ability to run fast under the saddle or trot at a rapid pace 

 before the carriage. 



Similarly, the beef animal, the dairy cow, the mutton 

 and wool sheep, the lard and bacon hog, the swift grey- 

 hound, the massive St. Bernard, the intelligent Scotch 

 collie and many other types useful to man have come 

 from methodical selection. 



272. Importance of selection in animal-breeding. 

 Careful study of the methods which have been practiced 

 by breeders of the domestic animals cannot fail to lead 

 to the inevitable conclusion that selection has been the 

 most important if not the chief principle followed in bring- 

 ing about the present highly developed forms among 

 animals. 



Certainly not all the phenomena which are exhibited 



