he child takes
after his grandparent or more remote ancestor of foreign blood. In other
cases, in which the breed has not been crossed, but some ancient character
has been lost through variation, it occasionally reappears through
reversion, so that the parents apparently fail to transmit their own
likeness. In all cases, however, we may safely conclude that the child
inherits all its characters from its parents, in whom certain characters
are latent, like the secondary sexual characters of one sex in the other.
When, after a long succession of bud-generations, a flower or fruit becomes
separated into distinct segments, having the colours or other attributes of
both parent-forms, we cannot doubt that these characters were latent in the
earlier buds, though they could not then be detected, or could be detected
only in an intimately commingled state. So it is with animals of crossed
parentage, which with advancing years occasionally exhibit characters
derived from one of their two parents, of which not a trace could at first
be perceived. Certain monstrosities, which resemble what naturalists call
the typical form of the group in question, {83} apparently come under the
same law of reversion. It is assuredly an astonishing fact that the male
and female sexual elements, that buds, and even full-grown animals, should
retain characters, during several generations in the case of crossed
breeds, and during thousands of generations in the case of pure breeds,
written as it were in invisible ink, yet ready at any time to be evolved
under the requisite conditions.

What these conditions are, we do not in many cases at all know. But the act
of crossing in itself, apparently from causing some disturbance in the
organisation, certainly gives a strong tendency to the reappearance of
long-lost characters, both corporeal and mental, independently of those
derived from the cross. A return of any species to its natural conditions
of life, as with feral animals and plants, favours reversion; though it is
certain that this tendency exists, we do not know how far it prevails, and
it has been much exaggerated. On the other hand, the crossed offspring of
plants which have had their organisation disturbed by cultivation, are more
liable to reversion than the crossed offspring of species which have always
lived under their natural conditions.

When distinguishable individuals of the same family, or races, or species
are crossed, we see that the