360 ON GENERATION. 



introduction of a vital principle or soul into the semen or 

 " geniture," can the aforementioned doctrine be defended. 



And hence have arisen all the controversies and problems 

 concerning the attraction of the magnet and of amber; on 

 sympathy and antipathy; on poisons and the contagion of 

 pestilential diseases; on alexipharmics and medicines which 

 prove curative or injurious through some hidden or rather un- 

 known property, all of which seem to come into play indepen- 

 dently of contact. And above all on what it is in generation 

 which, in virtue of a momentary contact nay, not even of 

 contact, save through several media forms the parts of the 

 chick from the egg by epigenesis in a certain order, and pro- 

 duces an " univocal" and like itself, and that entirely because it 

 was in contact at a former period. How, I ask again, does 

 that which is not present, and which only enjoyed extrinsic 

 contact, come to constitute and order all the members of the 

 chick in the egg exposed without the body of the parent, and 

 often at a long interval after it is laid ? how does it confer life 

 or soul, and a species compounded of those of the concurring 

 generants? Inasmuch as nothing, it seems, can reproduce 

 itself in another's likeness. 



EXERCISE THE FIFTIETH. 



' 



Of the efficient cause of animals, and its conditions. 



That we may proceed in our subject, therefore, and pene- 

 trate so far into the knowledge of the efficient cause of animal 

 generation as seems needful in this place, we must begin by 

 observing what instruments or media are devoted to it. And 

 here we come at once to the distinction into male and female ; 

 seminal fluid and ovum, and its primordium. For some males, 

 as well as some females, are barren, or but little prolific; and 

 the seed of the male is at one time more, at another time less 

 prolific ; because the semen masculinum stored up in the 

 vesiculse seminales is esteemed unfruitful, unless it is raised 



