similar to the present breeds, is worth little without knowing the date
of the domestication of such animals, which is far from being the case.
They may also with more weight aver that, knowing that organic beings
under domestication do vary in some degree, the argument from the great
difference between certain breeds is worth nothing, without we know the
limits of variation during a long course of time, which is far from the
case. They may argue that almost every county in England, and in many
districts of other countries, for instance in India, there are slightly
different breeds of the domestic animals; and that it is opposed to all
that we know of the distribution of wild animals to suppose that these
have descended from so many different wild races or species: if so, they
may argue, is it not probable that countries quite separate and exposed
to different climates would have breeds not slightly, but considerably,
different? Taking the most favourable case, on both sides, namely that
of the dog; they might urge that such breeds as the bull-dog and
turnspit have been reared by man, from the ascertained fact that
strictly analogous breeds (namely the Niata ox and Ancon sheep) in other
quadrupeds have thus originated. Again they may say, seeing what
training and careful selection has effected for the greyhound, and
seeing how absolutely unfit the Italian greyhound is to maintain itself
in a state of nature, is it not probable that at least all
greyhounds,--from the rough deerhound, the smooth Persian, the common
English, to the Italian,--have descended from one stock{207}? If so, is
it so improbable that the deerhound and long-legged shepherd dog have so
descended? If we admit this, and give up the bull-dog, we can hardly
dispute the probable common descent of the other breeds.

{207} _Origin_, Ed. i. p. 19, vi. p. 22.

The evidence is so conjectural and balanced on both sides that at
present I conceive that no one can decide: for my own part, I lean to
the probability of most of our domestic animals having descended from
more than one wild stock; though from the arguments last advanced and
from reflecting on the slow though inevitable effect of different races
of mankind, under different circumstances, saving the lives of and
therefore selecting the individuals most useful to them, I cannot doubt
but that one class of naturalists have much overrated the probable
number of the aboriginal wild stocks. As far as we