On The Generation Of Animals
consequently neither is the special sexual part so determined (if
really the same semen can become either male or female child, which
shows that the sexual part does not exist in the semen). Why, then,
should we assert this of this part any more than of others? For if
semen does not come from this part, the uterus, the same account may
be given of the others.
Again, some creatures come into being neither from parents of the
same kind nor from parents of a different kind, as flies and the
various kinds of what are called fleas; from these are produced
animals indeed, but not in this case of similar nature but a kind of
scolex. It is plain in this case that the young of a different kind
are not produced by semen coming from all parts of the parent, for
they would then resemble them, if indeed resemblance is a sign of
its coming from all parts.
Further even among animals some produce many young from a single
coition (and something like this is universal among plants, for it is
plain that they bear all the fruit of a whole season from a single
movement). And yet how would this be possible if the semen were
secreted from all the body? For from a single coition and a single
segregation of the semen scattered throughout the body must needs
follow only a single secretion. Nor is it possible for it to be
separated in the uterus, for this would no longer be a mere separation
of semen, but, as it were, a severance from a new plant or animal.
Again, the cuttings from a plant bear seed; clearly, therefore, even
before they were cut from the parent plant, they bore their fruit from
their own mass alone, and the seed did not come from all the plant.
But the greatest proof of all is derived from observations we have
sufficiently established on insects. For, if not in all, at least in
most of these, the female in the act of copulation inserts a part of
herself into the male. This, as we said before, is the way they
copulate, for the females manifestly insert this from below into the
males above, not in all cases, but in most of those observed. Hence it
seems clear that, when the males do emit semen, then also the cause of
the generation is not its coming from all the body, but something else
which must be investigated hereafter. For even if it were true that it
comes from all the body, as they say, they ought not to claim that
it comes from all parts of it, but only from the creative part- from
the workman, so to say, not the material he works in. Instead of that,
they talk as if one were to say that the semen comes from the shoes,
for, generally speaking, if a son is like his father, the shoes he
wears are like his father's shoes.
As to the vehemence of pleasure in sexual intercourse, it is not
because the semen comes from all the body, but because there is a
strong friction (wherefore if this intercourse is often repeated
the pleasure is diminished in the persons concerned). Moreover, the
pleasure is at the end of the act, but it ought, on the theory, to
be in each of the parts, and not at the same time, but sooner in
some and later in others.
If mutilated young are born of mutilated parents, it is for the same
reason as that for which they are like them. And the young of
mutilated parents are not always mutilated, just as they are not
always like their parents; the cause of this must be inquired into
later, for this problem is the same as that.
Again, if the female does not produce semen, it is reasonable to
suppose it does not come from all the body of the male either.
Conversely, if it does not come from all the male it is not
unreasonable to suppose that it does not come from the female, but