repair
of injuries into ordinary development and growth; it might therefore be
expected that every character would be as regularly transmitted by all the
methods of reproduction as by continued growth. In the chapters devoted to
inheritance it was shown that a multitude of newly-acquired characters,
whether injurious or beneficial, whether of the lowest or highest vital
importance, are often faithfully transmitted--frequently even when one
parent alone possesses some new peculiarity. It deserves especial attention
that characters appearing at any age tend to reappear at a corresponding
age. We may on the whole conclude that in all cases inheritance is the
rule, and non-inheritance the anomaly. In some instances a character is not
inherited, from the conditions of life being directly opposed to its
development; in many instances, from the conditions incessantly inducing
fresh variability, as with grafted fruit-trees and highly cultivated
flowers. In the remaining cases the failure may be attributed to reversion,
by which the child resembles its grandparents or more remote progenitors,
instead of its parents.

This principle of Reversion is the most wonderful of all the attributes of
Inheritance. It proves to us that the transmission of a character and its
development, which ordinarily go together and thus escape discrimination,
are distinct powers; and these powers in some cases are even antagonistic,
for each acts alternately in successive generations. Reversion is not a
rare event, depending on some unusual or favourable combination of
circumstances, but occurs so regularly with crossed animals and plants, and
so frequently with uncrossed breeds, that it is evidently an essential part
of the principle of inheritance. We know that {373} changed conditions have
the power of evoking long-lost characters, as in the case of some feral
animals. The act of crossing in itself possesses this power in a high
degree. What can be more wonderful than that characters, which have
disappeared during scores, or hundreds, or even thousands of generations,
should suddenly reappear perfectly developed, as in the case of pigeons and
fowls when purely bred, and especially when crossed; or as with the zebrine
stripes on dun-coloured horses, and other such cases? Many monstrosities
come under this same head, as when rudimentary organs are redeveloped, or
when an organ which we must believe was possessed by an early progenitor,
but of which no