ALBERT. MAGN. LIB.

flow, in which is the man's sperm, so that these two seeds run together in the woman's vulva, and one begins to mix with the other, and then the woman conceives. To conceive, however, is called when these two seeds are received in the matrix, and in such a place designated by nature for the fetus. After those two seeds are truly received, the woman's matrix is closed like a purse, on every side, so that she can lose nothing of the received seed. And when the matrix has been thus closed on all sides, the detention of the menstrual flows occurs in the woman.

Here the author executes the formation of the fetus, and first he does this, secondly he posits a notable point, there: According to which it is to be noted, if the man emits semen before the woman emits the menstrual flow, then conception does not occur. Likewise, if both emit at the same time, and if the seeds are not well conformed and well disposed, again conception will not occur, as if the man's semen were not sufficiently hot. And therefore those who rarely have intercourse generate quickly, because they are very hot. Note that the Vulva is so called as if it were a Valve, because it is the gate of the belly, and its last part is called the membrane, because the membrane of the anus is either the end of the Vulva, and thus the matrix is closed like a purse, so that according to Avicenna not even a needle could enter, because it rejoices in the heat received, not wanting to lose it. Note that the woman emits the menstrual flow and also receives it, and thus she is more delighted in intercourse for the man. But a doubt arises, whether one could generate if the testicles were cut off: and it seems that