ON GENERATION. 349 



nor as an animate substance transferring its vitality (anima) 

 to the chick. For in the egg there is no semen, neither does 

 any touch it, nor has ever done so ; (" and it is impossible 

 that that which does not touch should move, or that anything 

 should be affected by that which does not move it,") and there- 

 fore the vitality of the semen ought not to be said to exist in 

 it ; and although the vital principle may be the efficient in the 

 egg, yet it would not appear to result more from the cock or 

 his semen, than from the hen. 



Nor, indeed, is it transferred by any metempsychosis or 

 translation from the cock and his semen into the egg, and 

 thence into the chick. For how can this translation be carried 

 on into the eggs that are yet to exist, and to be conceived 

 after intercourse ? unless either some animate semen be in the 

 mean time working in some part of the hen ; or the vital 

 principle only have been translated without the seed, in order 

 to be infused into any egg which might thereafter be produced ; 

 but neither of these alternatives is true. For in no^part of 

 the hen is the semen to be found ; nor is it possible that the hen 

 after coition should be possessed of a double vital principle, 

 to wit, her own, and that of the future eggs and chicks; since 

 " the living principle or soul is said to be nowhere but in that 

 thing whose soul it is," much less can one or more vital prin- 

 ciples lie hidden in the hen, to be afterwards subservient to the 

 future eggs and chicks in their order, as they are produced. 



We have adduced these passages out of Aristotle in order 

 to set forth his opinion of the manner in which the seed of the 

 cock produces the chick from the egg ; and thereby throw at 

 least some light on this difficult question. But whereas the 

 said passages do not explain the mode in which this is ac- 

 complished, nor even solve the doubts proposed by himself, it 

 appiears that we are still sticking in the same mud, and caught 

 in the same perplexities (concerning the efficient cause of the 

 foetus in the generation of animals ;) indeed, so far from Aris- 

 totle's arguments rendering this question more clear, they ap- 

 pear on the contrary to involve it in more and greater doubts. 



Wherefore it is no wonder that the most excellent philoso- 

 pher was in perplexity on this head, and that he has admitted 

 so great a variety of efficient causes, and at one time has been 

 compelled to resort to automatons, coagulation, art, instruments, 



