On The Generation Of Animals
in few cases; but observations are not yet comprehensive enough to
enable us to make a distinction of classes. And generally it is the
rule with most of the oviparous fish and oviparous quadrupeds that the
female is larger than the because this is expedient in view of the
increase of bulk in conception by reason of the eggs. In the female
the part analogous to the uterus is cleft and extends along the
intestine, as with the other animals; in this are produced the results
of conception. This is clear in locusts and all other large insects
whose nature it is to unite; most insects are too small to be observed
in this respect.
Such is the character of the generative organs in animals which were
not spoken of before. It remains now to speak of the homogeneous parts
concerned, the seminal fluid and milk. We will take the former
first, and treat of milk afterwards.
Some animals manifestly emit semen, as all the sanguinea, but
whether the insects and cephalopoda do so is uncertain. Therefore this
is a question to be considered, whether all males do so, or not all;
and if not all, why some do and some not; and whether the female
also contributes any semen or not; and, if not semen, whether she does
not contribute anything else either, or whether she contributes
something else which is not semen. We must also inquire what those
animals which emit semen contribute by means of it to generation,
and generally what is the nature of semen, and of the so-called
catamenia in all animals which discharge this liquid.
Now it is thought that all animals are generated out of semen, and
that the semen comes from the parents. Wherefore it is part of the
same inquiry to ask whether both male and female produce it or only
one of them, and to ask whether it comes from the whole of the body or
not from the whole; for if the latter is true it is reasonable to
suppose that it does not come from both parents either. Accordingly,
since some say that it comes from the whole of the body, we must
investigate this question first.
The proofs from which it can be argued that the semen comes from
each and every part of the body may be reduced to four. First, the
intensity of the pleasure of coition; for the same state of feeling is
more pleasant if multiplied, and that which affects all the parts is
multiplied as compared with that which affects only one or a few.
Secondly, the alleged fact that mutilations are inherited, for they
argue that since the parent is deficient in this part the semen does
not come from thence, and the result is that the corresponding part is
not formed in the offspring. Thirdly, the resemblances to the parents,
for the young are born like them part for part as well as in the whole
body; if then the coming of the semen from the whole body is cause
of the resemblance of the whole, so the parts would be like because it
comes from each of the parts. Fourthly, it would seem to be reasonable
to say that as there is some first thing from which the whole
arises, so it is also with each of the parts, and therefore if semen
or seed is cause of the whole so each of the parts would have a seed
peculiar to itself. And these opinions are plausibly supported by such
evidence as that children are born with a likeness to their parents,
not in congenital but also in acquired characteristics; for before
now, when the parents have had scars, the children have been born with
a mark in the form of the scar in the same place, and there was a case
at Chalcedon where the father had a brand on his arm and the letter
was marked on the child, only confused and not clearly articulated.
That is pretty much the evidence on which some believe that the
semen comes from all the body.