230 MENTAL EVOLUTION IN ANIMALS. 



CHAPTER XV. 



Instinct (continued). 

 Domestication. 



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 observa- 

 tion can extend. But fortunately, from a time anterior to the 

 beginning of history, mankind, in the practice of domestica- 

 ting animals, has been engaged on making what we may 

 consider a gigantic experiment on this subject. Seeing that 

 the animals chosen for this purpose have been bred and 

 reared under human care for a series of innumerable genera- 

 tions, and that in some cases the members of certain 

 " breeds " are persistently selected and trained to perform 

 certain kinds of work, we should expect, if instincts arise by 

 secondary means in conjunction with primary, to find 

 evidence, not only of the dwindling of natural instincts, but 

 also of the formation of new and special instincts. For it 

 is evident that artificial education and artificial selection by 

 man are influences the same in kind, though not in degree, as 

 those of natural education and natural selection, to the com- 

 bined operation of which our theory ascribes the formation of 

 instincts. We might therefore, as I have said, expect to find 

 anions our domestic animals some evidence of the formation 

 of what we may call artificial, or in Mr. Darwin's phraseology, 

 domestic instincts. And such evidence we do find. 



Taking first the case of the impairment or loss of natural 

 instincts, I have already alluded to the striking example 

 supplied by the hereditary tameness of domesticated animals. 

 More, however, now remains to be said on this point, for it 



