GENERATION OF ANIMALS, IV. in. 



formec characteristic stands closer to what is peculiar 

 to him than the latter does. Now both the indi- 

 vidual and the genus to which it belongs are at 

 work in the act of generation ; but of the two the 

 indi\"idual takes the leading part, because this is the 

 really existent thing " ; the offspring also which 

 is formed, though of course it is formed so as to 

 possess the generic characteristics, at the same time 

 comes to be a particular indi\idual — and this, again, 

 is the really existent thing. Therefore, it is from 

 the " faculties " of all such things as these * that 

 the movements which are present in the semens 

 are derived, potentially even from <the faculties) of 

 earUer ancestors, but more specially of that which on 

 each occasion stands closer to some individual ; and 

 by individual I mean Coriscus, or Socrates. Now 

 everything, when it departs from type.*' passes not 

 into any casual thing but into its OAvn opposite ; 

 thus, applying this to the process of generation, the 

 (substance) which does not get mastered must of 

 necessity depart from type and become the opposite ** 

 in respect of that " faculty " wherein the generative 

 and motive agent has failed to gain the mastery. 

 Hence, if this is the " faculty " in Wrtue of which the 

 agent is male, then the offspring formed is female ; 

 if it is that in virtue of which the agent is Coriscus 

 or Socrates, then the offspring formed does not take 

 after its father but after its mother, since, just as 

 " mother " is the opposite of " father " as a general 

 term, so also the individual mother is the opposite 

 of the indixidual father. The same applies to the 

 " faculties " that stand next in order, since the off- 

 spring always tends to shift over to that one of its 

 ancestors which stands next, both on the father's side 



405 



