Mr. Yarrell
informed me that the Australian dingos, bred in the Zoological Gardens,
almost invariably produced in the first generation puppies marked with
white and other colours; but these introduced dingos had probably been
procured from the natives, who keep them in a semi-domesticated state. It
is certainly a remarkable fact that changed conditions should at first
produce, as far as we can see, absolutely no effect; but that they should
subsequently cause the character of the species to change. In the chapter
on pangenesis I shall attempt to throw a little light on this fact.

* * * * *

Returning now to the causes which are supposed to induce variability. Some
authors[633] believe that close interbreeding gives this tendency, and
leads to the production of monstrosities. In the seventeenth chapter some
few facts were advanced, showing that monstrosities are, as it appears,
occasionally thus caused; and there can be no doubt that close
interbreeding induces lessened fertility and a weakened constitution; hence
it may lead to variability: but I have not sufficient evidence on this
head. On the other hand, close interbreeding, if not carried to an
injurious extreme, far from causing variability, tends to fix the character
of each breed.

It was formerly a common belief, still held by some persons, that the
imagination of the mother affects the child in {264} the womb.[634] This
view is evidently not applicable to the lower animals, which lay
unimpregnated eggs, or to plants. Dr. William Hunter, in the last century,
told my father that during many years every woman in a large London
Lying-in Hospital was asked before her confinement whether anything had
specially affected her mind, and the answer was written down; and it so
happened that in no one instance could a coincidence be detected between
the woman's answer and any abnormal structure; but when she knew the nature
of the structure, she frequently suggested some fresh cause. The belief in
the power of the mother's imagination may perhaps have arisen from the
children of a second marriage resembling the previous father, as certainly
sometimes occurs, in accordance with the facts given in the eleventh
chapter.

* * * * *

_Crossing as a Cause of Variability._--In an early part of this chapter it
was stated that Pallas[635] and a few other naturalists maintain that
variability is wholly due to crossin