some additional organised matter will
thus have been expended.

From one of the forms of Reproduction, namely, spontaneous self-division,
we are led by insensible steps to the repair of the slightest injury; and
the existence of gemmules, derived from every cell or unit throughout the
body and everywhere diffused, explains all such cases,--even the wonderful
fact that, when the limbs of the salamander were cut off many times
successively by Spallanzani and Bonnet, they were exactly and completely
reproduced. I have heard this process compared with the recrystallisation
which occurs when the angles of a broken crystal are repaired; and the two
processes have this much in common, that in the one case the polarity of
the molecules is the efficient cause, and in the other the affinity of the
gemmules for particular nascent cells.

Pangenesis does not throw much light on Hybridism, but agrees well with
most of the ascertained facts. We may conclude from the fact of a single
spermatozoon or pollen-grain being insufficient for impregnation, that a
certain number of gemmules derived from each cell or unit are required for
the development of each part. From the occurrence of parthenogenesis, more
especially in the case of the silk-moth, in which the embryo is often
partially formed, we may also infer that the female element includes nearly
sufficient gemmules of all kinds for independent development, so that when
united with the male element the gemmules must be superabundant. Now, as a
general rule, when two species or races are crossed reciprocally, the
offspring do not differ, and this shows that both sexual elements agree in
power, in accordance with the view that they include the same gemmules.
Hybrids and mongrels are generally intermediate in character between the
two parent-forms, yet occasionally they closely resemble one parent in one
part and the other parent in another part, or even in their whole
structure: nor is this difficult to understand on {386} the admission that
the gemmules in the fertilised germ are superabundant in number, and that
those derived from one parent have some advantage in number, affinity, or
vigour over those derived from the other parent. Crossed forms sometimes
exhibit the colour or other characters of either parent in stripes or
blotches; and this may occur in the first generation, or through reversion
in succeeding bud and seminal generations, as in the several instances
given in the elev