SPECIES AND BREEDS. 141 
which has been urged with great persistency in 
recent discussions. I refer to the variability of . 
Species as shown in domestication. 
The domesticated animals with their numer- 
ous breeds are constantly adduced as evidence 
of the changes which animals may undergo, and 
as furnishing hints respecting the way in which 
the diversity now observed among animals may 
have been produced. It is my conviction that 
such inferences are in no way sustained by the 
facts of the case, and that, however striking the 
differences may be between the breeds of our 
domesticated animals, as compared with the wild 
Species of the same Genus, they are of a peculiar 
character, entirely distinct from the features pre- 
vailing among the latter, and altogether incident 
to the circumstances under which they appear. 
By this I do not mean the natural action of phys- 
ical conditions, but the more or less intelligent 
direction of the circumstances under which they 
live. The inference drawn from the varieties in- 
troduced among animals in a state of domestica- 
tion, with reference to the origin of Species, is 
usually this: that what the farmer does on a 
small scale Nature may do on a large one. It is 
true that man has been able to produce certain 
changes in the animals under his care, and that 
these changes have resulted in a variety of breeds. 
But in doing this, he has, in my estimation, in 
