208 SPECIAL INSTINCTS. Chap. VII. 



not keep lliese 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, with some de- 

 gree of selection, has probably concmred in civilizing by in- 

 heritance 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 

 imder 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 nm 

 (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 

 tliis instinct retained by our chickens has become useless 

 imder domestication, for the mother-hen has almost lost by 

 disuse the power of flight. 



Hence, we may conclude that, under domestication, in- 

 stincts have been acquired, and natural instincts have been 

 lost, partly by habit, and partly by man selecting and accumu- 

 lating, 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 

 othf^r cases compulsory habit has done nothing, and all has 

 been the result of selection, pursued both methodically and 

 imconsciously : but in most cases habit and selection have 

 probably acted together. 



Special J/isti?ii't^'i. 



We shall, perhaps, best understand how instincts in a slate 

 of nature have become modified by selection, by considering a 

 few cases. I will select only three, out of tliose Avhich I sliall 

 have to discuss in my future work — namely, the instinct which 

 leads the cuckoo to lay her eggs in other birds' nests : the 

 slave-making instinct of certain ants ; and the cell-making 

 power of the hive-bee : these two latter instincts have gcner- 



