History of Animals
handed down through three generations; for instance, a certain man had
a mark on his arm which his son did not possess, but his grandson
had it in the same spot though not very distinct.
Such cases, however, are few; for the children of cripples are
mostly sound, and there is no hard and fast rule regarding them. While
children mostly resemble their parents or their ancestors, it
sometimes happens that no such resemblance is to be traced. But
parents may pass on resemblance after several generations, as in the
case of the woman in Elis, who committed adultery with a negro; in
this case it was not the woman's own daughter but the daughter's child
that was a blackamoor.
As a rule the daughters have a tendency to take after the
mother, and the boys after the father; but sometimes it is the other
way, the boys taking after the mother and the girls after the
father. And they may resemble both parents in particular features.
There have been known cases of twins that had no resemblance
to one another, but they are alike as a general rule. There was once
upon a time a woman who had intercourse with her husband a week
after giving birth to a child and she conceived and bore a second
child as like the first as any twin. Some women have a tendency to
produce children that take after themselves, and others children
that take after the husband; and this latter case is like that of
the celebrated mare in Pharsalus, that got the name of the Honest
In the emission of sperm there is a preliminary discharge of
air, and the outflow is manifestly caused by a blast of air; for
nothing is cast to a distance save by pneumatic pressure. After the
seed reaches the womb and remains there for a while, a membrane
forms around it; for when it happens to escape before it is distinctly
formed, it looks like an egg enveloped in its membrane after removal
of the eggshell; and the membrane is full of veins.
All animals whatsoever, whether they fly or swim or walk upon
dry land, whether they bring forth their young alive or in the egg,
develop in the same way: save only that some have the navel attached
to the womb, namely the viviparous animals, and some have it
attached to the egg, and some to both parts alike, as in a certain
sort of fishes. And in some cases membranous envelopes surround the
egg, and in other cases the chorion surrounds it. And first of all the
animal develops within the innermost envelope, and then another
membrane appears around the former one, which latter is for the most
part attached to the womb, but is in part separated from it and
contains fluid. In between is a watery or sanguineous fluid, which the
women folk call the forewaters.
All animals, or all such as have a navel, grow by the navel. And
the navel is attached to the cotyledon in all such as possess
cotyledons, and to the womb itself by a vein in all such as have the
womb smooth. And as regards their shape within the womb, the
four-footed animals all lie stretched out, and the footless animals
lie on their sides, as for instance fishes; but two-legged animals lie
in a bent position, as for instance birds; and human embryos lie bent,
with nose between the knees and eyes upon the knees, and the ears free
at the sides.
All animals alike have the head upwards to begin with; but as
they grow and approach the term of egress from the womb they turn
downwards, and birth in the natural course of things takes place in
all animals head foremost; but in abnormal cases it may take place
in a bent position, or feet foremost.
The young of quadrupeds when they are near their full time
contain excrements, both liquid and in the form of solid lumps, the
latter in the lower part of the bowel and the urine in the bladder.