CHAPTER XVI. 
The intelligence of the dog is of special, and indeed of 
unique interest from an evolutionary point of view, in 
that from time out of record this animal has been domes- 
ticated on account of the high level of its natural intelli- 
gence ; and by persistent contact with man, coupled with 
training .and breeding, its natural intelligence has been 
greatly changed. In the result we see, not only a general 
modification in the way of dependent companionship and 
docility, so unlike the fierce and self-reliant disposition 
of all wild species of the genus ; but also a number of 
special modifications, peculiar to certain breeds, which all 
have obvious reference to the requirements of man. The 
whole psychological character of the dog may therefore be 
said to have been moulded by human agency wfith refer- 
ence to human requirements, so that now it is not more 
true that man has in a sense created the structure of the 
bull-dog and greyhound, than that he has implanted the 
instincts of the watch-dog and pointer. The definite 
proof which we thus have afforded of the transforming 
and creating influence exerted upon the mental character 
and instincts of species by long and persistent training, 
coupled with artificial selection, furnishes the strongest 
* possible corroboration of the theory which assigns psycho- 
logical development in general to the joint operation of 
individual experience coupled with natural selection. For 
thousands of years man has here been virtually, though 
unconsciously, performing what evolutionists may re- 
gard as a gigantic experiment upon the potency of in- 
dividual experience accumulated by heredity; and now 
there stands before us this most wonderful monument of 
