ON GENERATION. 359 



one time " the genital and foetific fluid/' at another, " the vital 

 virus/' For he says 1 : " The male fish sprinkles the ova with 

 his genital semen, and from the ova that are touched by this 

 vital virus young fishes are engendered." 



Let it then be admitted as matter of certainty that the em- 

 bryo is produced by contagion. But a great difficulty imme- 

 diately arises, when we ask : how, in what way is this contagion 

 the author of so great a work ? By what condition do parents 

 through it engender offspring like themselves, or how does the 

 semen masculinum produce an " univocal" like the male whence 

 it flowed ? When it disappears after the contact, and is neught 

 in act ulteriorly, either by virtue of contact or presence, but is 

 corrupt and has become a nonentity, how, I ask, does a non- 

 entity act ? How does a thing which is not in contact fashion 

 another thing like itself? How does a thing which is dead it- 

 self impart life to something else, and that only because at a 

 former period it was in contact ? 



For the reasoning of Aristotle 2 appears to be false, or at all 

 events defective, where he contends " That generation cannot 

 take place without an active and a passive principle; and that those 

 things can neither act nor prove passive which do not touch ; 

 but that those things come into mutual contact which, whilst 

 they are of different sizes, and are in different places, have 

 their extremes together." 



But when it clearly appears that contagion from noncontin- 

 gents, and things not having their extremities together, pro- 

 duce ill effects on animals, wherefore should not the same law 

 avail in respect of their life and generation? There is an 

 " efficient" in the egg which, by its plastic virtue (for the male 

 has only touched though he no longer touches, nor are there 

 any extremes together), produces and fashions the foetus in its 

 kind and likeness. And through so many media or instru- 

 ments is this power, the agent of fecundity, transmitted or 

 required that neither by any movement of instruments as in 

 works of art, nor by the instance of the automaton quoted by 

 Aristotle, nor of our clocks, nor of the kingdom in which the 

 mandate of the sovereign is everywhere of avail, nor yet by the 



1 Hist. Animal, lib. vi, cap. 13. * De Gen. et cor. lib. i, cap. 6. 



