after its third moult, or when
purely-bred bantams partially assume the red plumage of their prototype, we
cannot doubt that these qualities were from the first present, though
latent, in the individual animal, like the characters of a moth in the
caterpillar. Now, if these animals had produced offspring before they had
acquired with advancing age their new characters, nothing is more probable
than that they would have transmitted them to some of their offspring,
which in this case would in appearance have received such characters from
their grandparents or more distant progenitors. We should then have had a
case of reversion, that is, of the reappearance in the child of an
ancestral character, actually present, though during youth completely
latent, in the parent; and this we may safely conclude is what occurs with
reversions of all kinds to progenitors however remote.

This view of the latency in each generation of all the characters which
appear through reversion, is also supported by their actual presence in
some cases during early youth alone, or by their more frequent appearance
and greater distinctness at this age than during maturity. We have seen
that this is often the case with the stripes on the legs and faces of the
several species of the horse-genus. The Himalayan rabbit, when crossed,
sometimes produces offspring which revert to the parent silver-grey breed,
and we have seen that in purely bred animals pale-grey fur occasionally
reappears during early youth. Black cats, we may feel assured, would
occasionally produce by reversion tabbies; and on young black kittens, with
a pedigree[128] known to have been long pure, faint traces of stripes may
almost always be seen which afterwards disappear. Hornless Suffolk cattle
occasionally produce by reversion horned animals; and Youatt[129] asserts
that even in hornless individuals {56} "the rudiment of a horn may be often
felt at an early age."

No doubt it appears at first sight in the highest degree improbable that in
every horse of every generation there should be a latent capacity and
tendency to produce stripes, though these may not appear once in a thousand
generations; that in every white, black, or other coloured pigeon, which
may have transmitted its proper colour during centuries, there should be a
latent capacity in the plumage to become blue and to be marked with certain
characteristic bars; that in every child in a six-fingered family there
should be t