1884.] on the Darwinian Theory of Instinct. 139 



the ferrets were taken from the nest to be fed, that I adopted the plan 

 of giving them the milk in their nest, and with this arrangement the 

 hen seemed quite satisfied ; at any rate she used to chuck when she saw 

 the milk coming, and surveyed the feeding with evident satisfaction. 



Thus we see that even the oldest and most important of instincts 

 in bees and birds admit of being greatly modified, both in the indi- 

 vidual and in the race, by intelligent adaptation to changed conditions 

 of life ; and therefore we can scarcely doubt that the principle of 

 lapsing intelligence must be of much assistance to that of natural 

 selection in the origination and development of instinct. 



I shall now turn to another branch of the subject. From the 

 nature of the case it is not to be expected that we should obtain a 

 great variety of instances among wild animals of new instincts 

 acquired under human observation, seeing that the conditions of 

 their life, as a rule, remain pretty uniform for any periods over which 

 human oljservation can extend. But from a time before the begin- 

 ning of history, mankind, in the practice of domesticating animals, 

 has been making what we may now deem a gigantic experiment upon 

 the topic before us. 



The influences of domestication upon the psychology of animals 

 may be broadly considered as both negative and positive — negative 

 in the obliteration of natural instincts ; positive in the creation of 

 artificial instincts. I shall consider these two branches separately, 

 and here I may again revert to the obliteration of natural wildness. 

 We all know that the horse is an easily breakable animal, but his 

 nearest allies in a state of nature, the zebra and the quagga, are the 

 most obstinately unbreakable of animals. Similar remarks apply to 

 the natural wildness of all wild species of kine, as contrasted with 

 the innate tameness of our domesticated breeds. Consider again the 

 case of the cat. The domesticated animal is sufficiently tame, even 

 from kittenhood ; whereas its nearest cousin in a state of nature, the 

 wild cat, is perhaps of all animals the most untameable. But of 

 course it is in the case of the dog that we meet with the strongest 

 evidence on this point. The most general and characteristic features 

 in the psychology of all the domesticated varieties are faithfulness, 

 docility, and sense of dependence upon a master ; whereas the most 

 usual and characteristic features in the psychology of all the wild 

 species are fierceness, treachery, and self-reliance. But, not further 

 to pursue the negative side of this subject, let us now turn to the 

 positive, or to the power which man has shown himself to possess of 

 implanting new instincts in the mental constitution of animals. For 

 the sake of brevity I shall here confine myself to the most conspicuous 

 instance, which is of course furnished by the dog, seeing that the dog 

 has always been selected and trained with more or less express 

 reference to his mental qualities. And here I may observe that in 

 the process of modifying psychology by domestication exactly the 

 same principles have been brought into operation as those to which 

 we attribute the modification of instincts in general ; for the processes 



