tchen-garden, in comparison with the flowers of the same varieties;
and the diversity of fruit of the same species in the orchard, in
comparison with the leaves and flowers of the same set of varieties. See
how different the leaves of the cabbage are, and how extremely alike the
flowers; how unlike the flowers of the heartsease are, and how alike the
leaves; how much the fruit of the different kinds of gooseberries differ
in size, colour, shape, and hairiness, and yet the flowers present very
slight differences. It is not that the varieties which differ largely
in some one point do not differ at all in other points; this is hardly
ever, perhaps never, the case. The laws of correlation of growth,
the importance of which should never be overlooked, will ensure some
differences; but, as a general rule, I cannot doubt that the continued
selection of slight variations, either in the leaves, the flowers, or
the fruit, will produce races differing from each other chiefly in these
characters.

It may be objected that the principle of selection has been reduced to
methodical practice for scarcely more than three-quarters of a century;
it has certainly been more attended to of late years, and many treatises
have been published on the subject; and the result, I may add, has been,
in a corresponding degree, rapid and important. But it is very far from
true that the principle is a modern discovery. I could give several
references to the full acknowledgment of the importance of the principle
in works of high antiquity. In rude and barbarous periods of English
history choice animals were often imported, and laws were passed to
prevent their exportation: the destruction of horses under a certain
size was ordered, and this may be compared to the "roguing" of plants
by nurserymen. The principle of selection I find distinctly given in an
ancient Chinese encyclopaedia. Explicit rules are laid down by some of
the Roman classical writers. From passages in Genesis, it is clear that
the colour of domestic animals was at that early period attended to.
Savages now sometimes cross their dogs with wild canine animals, to
improve the breed, and they formerly did so, as is attested by passages
in Pliny. The savages in South Africa match their draught cattle by
colour, as do some of the Esquimaux their teams of dogs. Livingstone
shows how much good domestic breeds are valued by the negroes of the
interior of Africa who have not associated with Europea