conscious of, and have most control over_, such habits as speech, the
upright position, the arts and sciences, which are acquisitions peculiar
to the human race, always acquired after birth, and not common to
ourselves and any ancestor who had not become entirely human.

"II. That we are _less conscious of, and have less control over_, eating
and drinking, swallowing, breathing, seeing and hearing, which were
acquisitions of our prehuman ancestry, and for which we had provided
ourselves with all the necessary apparatus before we saw light, but
which are, geologically speaking, recent, or comparatively recent.

"III. That we are _most unconscious of, and have least control over_,
our digestion and circulation, which belonged even to our invertebrate
ancestry, and which are habits, geologically speaking, of extreme
antiquity.... Does it not seem as though the older and more confirmed
the habit, the more unquestioning the act of volition, till, in the case
of the oldest habits, the practice of succeeding existences has so
formulated the procedure, that, on being once committed to such and such
a line beyond a certain point, the subsequent course is so clear as to
be open to no further doubt, to admit of no alternative, till the very
power of questioning is gone, and even the consciousness of volition"
(pp. 51-2).

The hypothesis then, that heredity and development are due to
unconscious memory, finds much to support it--"the self-development of
each new life in succeeding generations--the various stages through
which it passes (as it would appear, at first sight, without rhyme or
reason), the manner in which it prepares structures of the most
surpassing intricacy and delicacy, for which it has no use at the time
when it prepares them, and the many elaborate instincts which it
exhibits immediately on, and indeed before, birth--all point in the
direction of habit and memory, as the only causes which could produce
them" (p. 125). The hypothesis explains, for instance, the fact of
recapitulation:--"Why should the embryo of any animal go through so many
stages--embryological allusions to forefathers of a widely different
type? And why, again, should the germs of the same kind of creature
always go through the same stages? If the germ of any animal now living
is, in its simplest state, but part of the personal identity of one of
the original germs of all life whatsoever, and hence, if any now living
organism must be consider