head. But as animals kept by savages
have to provide their own food, either entirely or to a large extent,
throughout the year, it can hardly be doubted that, in different countries,
varieties differing in constitution and in various characters would succeed
best, and so be naturally selected. Hence perhaps it is that the few
domesticated animals kept by savages partake, as has been remarked by more
than one writer, of the wild appearance of their masters, and likewise
resemble natural species. Even in long-civilised countries, at least in the
wilder parts, natural selection must act on our domestic races. It is
obvious that varieties, having very different habits, constitution, and
structure, would succeed best on mountains and on rich lowland pastures.
For example, the improved Leicester sheep were formerly taken to the
Lammermuir Hills; but an intelligent sheep-master reported that "our coarse
lean pastures were unequal to the task of supporting such heavy-bodied
sheep; and they gradually dwindled away into less and less bulk: {225} each
generation was inferior to the preceding one; and when the spring was
severe, seldom more than two-thirds of the lambs survived the ravages of
the storms."[535] So with the mountain cattle of North Wales and the
Hebrides, it has been found that they could not withstand being crossed
with the larger and more delicate lowland breeds. Two French naturalists,
in describing the horses of Circassia, remark that, subjected as they are
to extreme vicissitudes of climate, having to search for scanty pasture,
and exposed to constant danger from wolves, the strongest and most vigorous
alone survive.[536]

Every one must have been struck with the surpassing grace, strength, and
vigour of the Game-cock, with its bold and confident air, its long, yet
firm neck, compact body, powerful and closely pressed wings, muscular
thighs, strong beak massive at the base, dense and sharp spurs set low on
the legs for delivering the fatal blow, and its compact, glossy, and
mail-like plumage serving as a defence. Now the English game-cock has not
only been improved during many years by man's careful selection, but in
addition, as Mr. Tegetmeier has remarked,[537] by a kind of natural
selection, for the strongest, most active and courageous birds have
stricken down their antagonists in the cockpit, generation after
generation, and have subsequently served as the progenitors of their kind.

In Great Britain, in f