us in our ignorance to act
capriciously, transmitting a character with inexplicable strength or
feebleness. The very same peculiarity, as the weeping habit of trees,
silky-feathers, &c., may be inherited either firmly or not at all by
different members of the same group, and even by different individuals of
the same species, though treated in the same manner. In this latter case we
see that the power of transmission is a quality which is merely individual
in its attachment. As with single characters, so it is with the several
concurrent slight differences which distinguish sub-varieties or races; for
of these, some can be propagated almost as truly as species, whilst others
cannot be relied on. The same rule holds good with plants, when propagated
by bulbs, offsets, &c., which in one sense still form parts of the same
individual, for some varieties retain or inherit through successive
bud-generations their character far more truly than others.

Some characters not proper to the parent-species have certainly been
inherited from an extremely remote epoch, and may therefore be considered
as firmly fixed. But it is doubtful whether length of inheritance in itself
gives fixedness of character; {82} though the chances are obviously in
favour of any character which has long been transmitted true or unaltered,
still being transmitted true as long as the conditions of life remain the
same. We know that many species, after having retained the same character
for countless ages, whilst living under their natural conditions, when
domesticated have varied in the most diversified manner, that is, have
failed to transmit their original form; so that no character appears to be
absolutely fixed. We can sometimes account for the failure of inheritance
by the conditions of life being opposed to the development of certain
characters; and still oftener, as with plants cultivated by grafts and
buds, by the conditions causing new and slight modifications incessantly to
appear. In this latter case it is not that inheritance wholly fails, but
that new characters are continually superadded. In some few cases, in which
both parents are similarly characterised, inheritance seems to gain so much
force by the combined action of the two parents, that it counteracts its
own power, and a new modification is the result.

In many cases the failure of the parents to transmit their likeness is due
to the breed having been at some former period crossed; and t