GENERATION OF ANIMALS, IV. i. 



gone a change,* and first and foremost the blood- 

 vessels, on to which the fleshy structure of the body 

 has been applied all round, as on to a framework.* 

 And it is reasonable to suppose not that the blood- 

 vessels have been formed to be of a particular charac- 

 ter on account of the uterus, but rather that the 

 uterus has been so formed on account of them, since 

 although each is a receptacle of blood in some form, 

 the blood-vessels are prior to the uterus ; and the 

 motive principle must of necessity be prior always 

 and be the cause of the process of formation in \irtue 

 of possessing a particular character.*^ So then, this 

 difference of the sexual parts as between males and 

 females is a contingent phenomenon ** : we must not 

 look upon it as being a " principle " or a cause : this 

 function is fulfilled by something else, even though 

 no semen at all is discharged either by the female or 

 by the male and whatever the manner may really be 

 by which the forming creature takes shape. 



The same argument which we used against Empe- 

 docles and Democritus holds good against those 

 who allege that the male comes from the right side 

 and the female from the left * : thus if the male con- 

 tributes no material at all, then those who take this 

 \-iew are of course talking nonsense ; if on the other 

 hand it does contribute something, as they assert, we 

 have to counter them in the same way that we 

 countered Empedocles' argument which draws the 

 line as between male and female by reference to 

 the heat and coldness of the uterus. They make 

 the same mistake as he does, ih drawing the line by 



is an " accidental," not an " essential," characteristic. For the 

 sentiment, see 766 b 3 ff . 



' e.g., Anaxagoras ; see 763 b 33. 



381 



