Home | Texts by category | | Quick Search:   
Works by Aristotle
Pages of On The Generation Of Animals

Previous | Next

On The Generation Of Animals   

weasel has a uterus in like manner to the other quadrupeds; by what
passage is the embryo to get from it to the mouth? But this opinion
has arisen because the young of the weasel are very small like those
of the other fissipeds, of which we shall speak later, and because
they often carry the young about in their mouths.

Much deceived also are those who make a foolish statement about
the trochus and the hyena. Many say that the hyena, and Herodorus
the Heracleot says that the trochus, has two pudenda, those of the
male and of the female, and that the trochus impregnates itself but
the hyena mounts and is mounted in alternate years. This is untrue,
for the hyena has been seen to have only one pudendum, there being
no lack of opportunity for observation in some districts, but hyenas
have under the tail a line like the pudendum of the female. Both
male and female have such a mark, but the males are taken more
frequently; this casual observation has given rise to this opinion.
But enough has been said of this.


Touching the generation of fish, the question may be raised, why
it is that in the cartilaginous fish neither the females are seen
discharging their eggs nor the males their milt, whereas in the
non-viviparous fishes this is seen in both sexes. The reason is that
the whole cartilaginous class do not produce much semen, and further
the females have their uterus near hypozoma. For the males and females
of the one class of fish differ from the males and females of the
other class in like manner, for the cartilaginous are less
productive of semen. But in the oviparous fish, as the females lay
their eggs on account of their number, so do the males shed their milt
on account of its abundance. For they have more milt than just what is
required for copulation, as Nature prefers to expend the milt in
helping to perfect the eggs, when the female has deposited them,
rather than in forming them at first. For as has been said both
further back and in our recent discussions, the eggs of birds are
perfected internally but those of fish externally. The latter, indeed,
resemble in a way those animals which produce a scolex, for the
product discharged by them is still more imperfect than a fish's
egg. It is the male that brings about the perfection of the egg both
of birds and of fishes, only in the former internally, as they are
perfected internally, and in the latter externally, because the egg is
imperfect when deposited; but the result is the same in both cases.

In birds the wind-eggs become fertile, and those previously
impregnated by one kind of cock change their nature to that of the
later cock. And if the eggs be behindhand in growth, then, if the same
cock treads the hen again after leaving off treading for a time, he
causes them to increase quickly, not, however, at any period
whatever of their development, but if the treading take place before
the egg changes so far that the white begins to separate from the
yolk. But in the eggs of fishes no such limit of time has been laid
down, but the males shed their milt quickly upon them to preserve
them. The reason is that these eggs are not two-coloured, and hence
there is no such limit of time fixed with them as with those of birds.
This fact is what we should expect, for by the time that the white and
yolk are separated off from one another, the birds egg already
contains the principle that comes from the male parent.... for the
male contributes to this.

Wind-eggs, then, participate in generation so far as is possible for
them. That they should be perfected into an animal is impossible,
for an animal requires sense-perception; but the nutritive faculty
of the soul is possessed by females as well as males, and indeed by
all living things, as has been often said, wherefore the egg itself is

Previous | Next
Site Search