attributed to the temperament or to the active qualities, which consists
in heat and cold and the nature of the matter under them--that is, the
flowing of the menstruous blood. But now, the seed, say they, affords
both force to procreate and to form the child, as well as matter for its
generation; and in the menstruous blood there is both matter and force,
for as the seed most helps the maternal principle, so also does the
menstrual blood the potential seed, which is, says Galen, blood well
concocted by the vessels which contain it. So that the blood is not only
the matter of generating the child, but also seed, it being impossible
that menstrual blood has both principles.

The ancients also say that the seed is the stronger efficient, the
matter of it being very little in quantity, but the potential quality of
it is very strong; wherefore, if these principles of generation,
according to which the sex is made were only, say they, in the menstrual
blood, then would the children be all mostly females; as were the
efficient force in the seed they would be all males; but since both have
operation in menstrual blood, matter predominates in quantity and in the
seed force and virtue. And, therefore, Galen thinks that the child
receives its sex rather from the mother than the father, for though his
seed contributes a little to the natural principle, yet it is more
weakly. But for likeliness it is referred rather to the father than to
the mother. Yet the woman's seed receiving strength from the menstrual
blood for the space of nine months, overpowers the man's in that
particular, for the menstrual blood rather cherishes the one than the
other; from which it is plain the woman affords both matter to make and
force and virtue to perfect the conception; though the female's be fit
nutriment for the male's by reason of the thinness of it, being more
adapted to make up conception thereby. For as of soft wax or moist clay,
the artificer can frame what he intends, so, say they, the man's seed