es that there formerly existed in Great Britain
eleven wild species of sheep peculiar to it! When we bear in mind that
Britain has now hardly one peculiar mammal, and France but few distinct
from those of Germany and conversely, and so with Hungary, Spain, &c., but
that each of these kingdoms possesses several peculiar breeds of cattle,
sheep, &c, we must admit that many domestic breeds have originated in
Europe; for whence could they have been derived, as these several countries
do not possess a number of peculiar species as distinct parent-stocks? So
it is in India. Even in the case of the domestic dogs of the whole world,
which I fully admit have probably descended from several wild species, I
cannot doubt that there has been an immense amount of inherited variation.
Who can believe that animals closely resembling the Italian greyhound, the
bloodhound, the bull-dog, or Blenheim spaniel, &c.--so unlike all wild
Canidae--ever existed freely in a state of nature? It has often been loosely
said that all our races of dogs have {20} been produced by the crossing of
a few aboriginal species; but by crossing we can only get forms in some
degree intermediate between their parents; and if we account for our
several domestic races by this process, we must admit the former existence
of the most extreme forms, as the Italian greyhound, bloodhound, bull-dog,
&c., in the wild state. Moreover, the possibility of making distinct races
by crossing has been greatly exaggerated. There can be no doubt that a race
may be modified by occasional crosses, if aided by the careful selection of
those individual mongrels, which present any desired character; but that a
race could be obtained nearly intermediate between two extremely different
races or species, I can hardly believe. Sir J. Sebright expressly
experimentised for this object, and failed. The offspring from the first
cross between two pure breeds is tolerably and sometimes (as I have found
with pigeons) extremely uniform, and everything seems simple enough; but
when these mongrels are crossed one with another for several generations,
hardly two of them will be alike, and then the extreme difficulty, or
rather utter hopelessness, of the task becomes apparent. Certainly, a breed
intermediate between _two very distinct_ breeds could not be got without
extreme care and long-continued selection; nor can I find a single case on
record of a permanent race having been thus formed.

_On the Bre