is said to be of a dun colour, with a largish head, and a great many
other peculiarities; while the best authorities on the wild Horses of
South America tell you that there is no similarity between their wild
Horses and those of Asia Minor; the cut of their heads is very
different, and they are commonly chestnut or bay-coloured. It is quite
clear, therefore, that as by these facts there ought to have been two
primitive stocks, they go for nothing in support of the assumption that
races recur to one primitive stock, and so far as this evidence is
concerned, it falls to the ground.

Suppose for a moment that it were so, and that domesticated races, when
turned wild, did return to some common condition, I cannot see that
this would prove much more than that similar conditions are likely to
produce similar results; and that when you take back domesticated
animals into what we call natural conditions, you do exactly the same
thing as if you carefully undid all the work you had gone through, for
the purpose of bringing the animal from its wild to its domesticated
state. I do not see anything very wonderful in the fact, if it took
all that trouble to get it from a wild state, that it should go back
into its original state as soon as you removed the conditions which
produced the variation to the domesticated form. There is an important
fact, however, forcibly brought forward by Mr. Darwin, which has been
noticed in connection with the breeding of domesticated pigeons; and it
is, that however different these breeds of pigeons may be from each
other, and we have already noticed the great differences in these
breeds, that if, among any of those variations, you chance to have a
blue pigeon turn up, it will be sure to have the black bars across the
wings, which are characteristic of the original wild stock, the Rock
Pigeon.