294 ON GENERATION. 



the membranes, to wit, and the fluids, produced by any kind of 

 coagulation j neither is there any thing like curdled milk to be 

 discovered in the uterus, as must be obvious from the foregoing 

 exercises. It follows, therefore, and from thence, that neither 

 does the conception, whence the animal springs, as the herb arises 

 from a fruitful seed, comport itself in the manner Aristotle 

 imagined, since this takes place in viviparous animals in the 

 same way as the egg is formed in oviparous animals, as he him- 

 self avows, and as shall be demonstrated by and by in our ob- 

 servations. Because it is certain that eggs of every descrip- 

 tion prolific and barren are engendered and formed by the 

 hen singly, but that fecundity accrues from the male alone ; 

 the cock, I say, contributes neither form nor matter to the egg, 

 but that only by which it becomes fertile and fit to engender a 

 chick. And this faculty the cock confers by his semen (geni- 

 tura), emitted in the act of intercourse, not only on the egg 

 that is already begun, or is already formed, but on the uterus 

 and ovaiy, and even on the body of the fowl herself, in such 

 wise that eggs which have yet to be produced, eggs, none of the 

 matter of which yet exists either in the ovary or in any other 

 part of the body, are thence produced possessed of fecundity. 



EXERCISE THE THIRTY-SECOND. 



Nor in the manner imagined by physicians. 



Conception, according to the opinion of medical men, takes 

 place in the following way : during intercourse the male and 

 female dissolve in one voluptuous sensation, and eject their 

 seminal fluids (geniturse) into the cavity of the uterus, where 

 that which each contributes is mingled with that which the 

 other supplies, the mixture having from both equally the faculty 

 of action and the force of matter; and according to the predomi- 

 nance of this or of that geniture does the progeny turn out male 

 or female. It is farther imagined that immediately after the 

 intercourse, the active and passive principles cooperating, some- 

 thing of the conception is formed in the uterus. For contrary 

 to the Aristotelians, they maintain that the male is no more the 



