214 THE ORIGIN OF SPECIES 



once displayed, methodical selection and the inherited effects of 

 compulsory training in each successive generation would soon 

 complete the work; and unconscious selection is still in progress, 

 as each man tries to procure, without intending to improve the 

 breed, dogs which stand and hunt best. On the other hand, habit 

 alone in some cases has sufficed; hardly any animal is more diffi- 

 cult to tame than the young of the wild rabbit; scarcely any ani- 

 mal is tamer than the young of the tame rabbit; but I can hardly 

 suppose that domestic rabbits have often been selected for tame- 

 ness alone; so that we must attribute at least the greater part of 

 the inherited change 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 civilized 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 civilizing 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 domes- 

 tication, for the mother hen has almost lost by disuse the power 

 of flight. 



