GENERATION OF ANIMALS, 11. ii.-iii. 



which consists of the tiniest particles, so small that 

 each Lndi\'idual bubble cannot be detected by the eye. 

 An instance of such a foam, mentioned earUer, is 

 that produced by the mechanical mixing of water 

 and oil. 



That the natural substance of semen is foam-like 

 was, so it seems, not unknown even in early days ; 

 at any rate, the goddess who is supreme in matters of 

 sexual intercourse was called after foam." 



We have now given the reason which solves the 

 puzzle that was stated. And this also shows, inci- 

 dentally, why semen does not freeze : it is because 

 air is imper\'ious to frost. 



The next puzzle to be stated and solved is this. Ill 

 Take the case of those groups of animals in which g*™,®" *"^ 

 semen is emitted into the female by the male. Su|>- 

 posing it is true that the semen which is so intro- 

 duced is not an ingredient in the fetation ^ which is 

 formed, but performs its function simply by means 

 of the dynamis '^ which it contains. Verj- well ; if so, 

 what becomes of the physical part of it ? First of all 

 we shall have to decide (a) whether that which takes 

 shape within the female does or does not incorporate 

 into itself any portion of that which was introduced 

 (from the male) ; and (6) whether Soul — and it is in 

 ^•irtue of Soul that an animal has the name of 

 " animal " : it is in fact in virtue of the sentient 

 part ** of Soul that it is an animal ^ — whether Soul is 

 or is not in the semen and in the fetation to begin 

 \^ith, and if so where it comes from. No one, of 

 course, would maintain that the fetation is quite 

 without Soul, completely devoid of life in every sense, 



' See also 726 b 18 ff., 727 b 15, 16, 738 b \2. and Bk. I, 

 ch. 21. " See Introd. § 43. 'See 732 a 13, n. 



165 



