16 THE HORSE BOOK. 



hand. There has been continuity of effort only 

 here and there. Environment has been vastly 

 different. Thus must we reach the inevitable 

 conclusion that the personal equation and en- 

 vironment, as directors of the forces of hered- 

 ity, are the chief factors in domestic animal 

 breeding', while the propagation of the wild ani- 

 mals is governed by ah inexorable law which 

 knows no change. The cases are not similar. 



All this forms a condition, not a theory. 

 There is nothing in it to discourage any one 

 from undertaking the breeding of improved do- 

 mestic animals. Its lesson simply is that when 

 he undertakes that work the breeder must make 

 up his mind to face a problem full of complex- 

 ity in which the natural tendency is downward 

 rather than upward. Too much stress has hith- 

 erto been laid on the force of heredity, too little 

 on the personal equation and environment. 

 The travesties on our improved breeds which 

 one sees on every hand are proof enough of this 

 contention. 



Size in draft horses and action in high-step- 

 pers are soon lost whenever the environment 

 which produced these characteristics is changed. 

 The Percheron, the Clydesdale or the Shire al- 

 lowed to breed indiscriminately on the range 

 ceases after a time to be a draft horse and be- 

 comes a range horse, because his range environ- 

 ment is stronger than the draft inheritance be- 

 queathed to him. On the other hand we may 



