DOGS AND MASTERS. 185 



one, because its native functions can have free 

 play in no other way. Among a few dogs, 

 like those of Constantinople, the instinct may 

 have died out by disuse, as the eyes of cave 

 animals have atrophied for want of light ; but 

 when a dog has once been brought up from 

 puppyhood under a master, the instinct is 

 fully and freely developed, and the masterless 

 condition is thenceforth for him a thwarting 

 and disappointing of all his natural feelings 

 and affections. 



Not only have dogs as a class acquired a 

 special instinct with regard to humanity gene- 

 rally, but particular breeds of dogs have ac- 

 quired particular instincts with regard to cer- 

 tain individual acts. Nobody doubts that the 

 muscles of a greyhound are specially correlated 

 to the acts of running and leaping ; or that the 

 muscles of a bull-dog are specially correlated to 

 the act of fighting. The whole external form 

 of these creatures has been modified by man's 

 selective action for a deliberate purpose : we 

 breed, as we say, from the dog with the best 



