CHAP. VII.] IN DOMESTICATED ANIMALS. 197 



from extreme wildness to extreme tameness, to habit and long- 

 continued close confinement. 



Natural instincts are lost under domestication : a remarkable 

 instance of this is seen in those breeds of fowls which very rarely 

 or never become " broody," that is, never wish to sit on their eggs. 

 Familiarity alone prevents our seeing how largely and how per- 

 manently the minds of our domestic animals have been modified. 

 It is scarcely possible to doubt that the love of man has become 

 instinctive in the dog. All wolves, foxes, jackals, and species of 

 the cat genus, when kept tame, are most eager to attack poultry, 

 sheep, and pigs ; and this tendency has been found incurable in 

 dogs which have been brought home as puppies from countries 

 such as Tierra del Fuego and Australia, where the savages do not 

 keep these domestic animals. How rarely, on the other hand, do 

 our civilised dogs, even when quite young, require to be taught 

 not to attack poultry, sheep, and pigs ! No doubt they occasionally 

 do make an attack, and are then beaten ; and if not cured, they 

 are destroyed ; so that habit and some degree of selection have 

 probably concurred in civilising by inheritance our dogs. On 

 the other hand, young chickens have lost, wholly by habit, that 

 fear of the dog and cat which no doubt was originally instinctive 

 in them ; for I am informed by Captain Hutton that the young 

 chickens of the parent-stock, the Gallus bankiva, when reared in 

 India under a hen, are at first excessively wild. So it is with 

 young pheasants reared in England under a hen. It is not that 

 chickens have lost all fear, but fear only of dogs and cats, for if 

 the hen gives the danger-chuckle, they will run (more especially 

 young turkeys) from under her, and conceal themselves in the 

 surrounding grass or thickets ; and this is evidently done for the 

 instinctive purpose of allowing, as we see in wild ground-birds, 

 their mother to fly away. But this instinct retained by our 

 chickens has become useless under domestication, for the mother- 

 hen has almost lost by disuse the power of flight. 



Hence, we may conclude, that under domestication instincts 

 have been acquired, and natural instincts have been lost, partly 

 by habit, and partly by man selecting and accumulating, during 

 successive generations, peculiar mental habits and actions, which 

 at first appeared from what we must in our ignorance call an 

 accident. In some cases compulsory habit alone has sufficed to 

 produce inherited mental changes; in other cases, compulsory 

 habit has done nothing, and all has been the result of selection, 

 pursued both methodically and unconsciously : but in most cases 

 habit and selection have probably concurred. 



Special Instincts, 

 We shall, perhaps, best understand how instincts in a state of 



