358 ON GENERATION. 



intercourse and the first conception engendered by both pa- 

 rents ; neither does he observe on the egg produced originally 

 in the cluster of the vitellarium, and without any geniture, whe- 

 ther proceeding from the male or the female, translated to the 

 uterus. Neither does he understand that the uterus is, even 

 after intercourse, completely empty of matter of every kind, 

 whether transmitted by the parents, or produced by the inter- 

 course, or transmuted in any way whatever. Neither had he 

 read, or at all events he does not refer to the experiment of 

 Fabricius, namely, that a hen is rendered so prolific by a few 

 treads of the cock, that she will continue to lay fruitful eggs 

 for the rest of the year, although in the interval she receives 

 no new accessions of semen for the fecundation of each egg as 

 it is laid, neither does she retain any of the seminal fluid which 

 she received so long ago. 



So much is certain, and disputed by no one, that animals, 

 all those at least that proceed from the intercourse of male and 

 female, are the offspring of this intercourse, and that they are 

 procreated as it" seems by a kind of contagion, much in the 

 same way as medical men observe contagious diseases, such as 

 leprosy, lues venera, plague, phthisis, to creep through the 

 ranks of mortal men, and by mere extrinsic contact to excite 

 diseases similar to themselves in other bodies ; nay, contact is 

 not necessary ; a mere halitus or miasm suffices, and that at a 

 distance and by an inanimate medium, and with nothing sensibly 

 altered : that is to say, where the contagion first touches, there 

 it generates an " univocal" like itself, neither touching nor ex- 

 isting in fact, neither being present nor conjunct, but solely 

 because it formerly touched. Such virtue and efficacy is found 

 in contagions. And the same thing perchance occurs iri the 

 generation of animals. For the eggs of fishes, which come 

 spontaneously to their full size extrinsically, and without any 

 addition of male seminal fluid, and are therefore indubitably 

 possessed of vitality without it, merely sprinkled and touched 

 with the milt of the male, produce young fishes. The semen 

 of the male, I say, is not intromitted in such wise as to per- 

 form the part of " agent" in each particular egg, or to fashion 

 the body, or to introduce vitality (anima) ; the ova are only 

 fecundated by a kind of contagion. Whence Aristotle calls the 

 milt of the male fish, or the genital fluid diffused in water, at 



