succeed from a poor seedling growing wild, if it had come from a
garden-stock. The pear, though cultivated in classical times, appears,
from Pliny s description, to have been a fruit of very inferior
quality. I have seen great surprise expressed in horticultural works at
the wonderful skill of gardeners, in having produced such splendid
results from such poor materials; but the art, I cannot doubt, has been
simple, and, as far as the final result is concerned, has been followed
almost unconsciously. It has consisted in 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 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
35