n always cultivating the best known variety, sowing its seeds,
and, when a slightly better variety has chanced to appear, selecting it,
and so onwards. But the gardeners of the classical period, who cultivated
the best pear they could procure, never thought what splendid fruit we
should eat; though we owe our excellent fruit, in some small degree, to
their having naturally chosen and preserved the best varieties they could
anywhere find.

A large amount of change in our cultivated plants, thus slowly and
unconsciously accumulated, explains, as I believe, the well-known fact,
that in a vast number of cases we cannot recognise, and therefore do not
know, the wild parent-stocks of the plants which have been longest
cultivated in our flower and kitchen gardens. If it has taken centuries or
thousands of years to improve or modify most of our plants up to their
present {38} standard of usefulness to man, we can understand how it is
that neither Australia, the Cape of Good Hope, nor any other region
inhabited by quite uncivilised man, has afforded us a single plant worth
culture. It is not that these countries, so rich in species, do not by a
strange chance possess the aboriginal stocks of any useful plants, but that
the native plants have not been improved by continued selection up to a
standard of perfection comparable with that given to the plants in
countries anciently civilised.

In regard to the domestic animals kept by uncivilised man, it should not be
overlooked that they almost always have to struggle for their own food, at
least during certain seasons. And in two countries very differently
circumstanced, individuals of the same species, having slightly different
constitutions or structure, would often succeed better in the one country
than in the other; and thus by a process of "natural selection," as will
hereafter be more fully explained, two sub-breeds might be formed. This,
perhaps, partly explains what has been remarked by some authors, namely,
that the varieties kept by savages have more of the character of species
than the varieties kept in civilised countries.

On the view here given of the all-important part which selection by man has
played, it becomes at once obvious, how it is that our domestic races show
adaptation in their structure or in their habits to man's wants or fancies.
We can, I think, further understand the frequently abnormal character of
our domestic races, and likewise their differences be