138 THE DOCTRINE OF DESCENT. 
species; that is to say, in regard to the new characters 
evolved by breeding, they are in a state of merely artificial 
stability ; and, if abandoned to accidental or irregular 
intermixture with the aboriginal or other races, they 
gradually revert to their primitive form. But it is ar- 
bitrary and erroneous to assert that all unconsciously 
or consciously bred races, without exception, are no new 
species, and would all relapse if left to a state of nature. 
Granting that all the races of fowls were left to them- 
selves, we must certainly admit the possibility that in 
India some few forms would change back into the Bankiva 
fowl. Itis, however, evident that, in Europe and America, 
from any semi-feral races of fowls the aboriginal Indian 
race would never reappear, but at the most some few new 
wide-spread mongrel forms would arise, remaining con- 
stant accordinz to geographical districts. No one has 
yet been able to assert that the wild dogs of the East, 
entirely released from the control of man, have become 
wolves or jackals, their presumptive ancestors. They 
become “ jackal-like,” by which every one expresses that 
the dog which became and was bred a domestic animal 
thousands of years ago, preserves its acquired specific 
characteristics even under circumstances most favour- 
able to their destruction. 
This statement, that domestic animals are no new 
species, is the more unfounded, as of several domestic 
animals the aboriginal stock is totally unknown ; among 
these are the sheep and goat, respecting the ancestors 
of which only vague conjectures can be framed. The 
most ancient race of sheep known to us,—that with ram- 
like horns, found among the lake dwellings of Switzer- 
land, throws no light upon the subject; and empirically 
