GENERATION OF ANIMALS, IV. i.-ii. 



inasmuch as the male possesses in itself a principle 

 of such a kind °' as to set up movement [in the animal 

 as well] and thoroughly to concoct the ultimate 

 nourishment, whereas the female's semen contains 

 material only. If (the male semen) gains ^ the 

 mastery, it brings (the material) over to itself; but 

 if it gets mastered, it changes over either into its 

 opposite or else into extinction. And the opposite of 

 the male is the female, which is female in \irtue of 

 its inability to effect concoction, and of the coldness 

 of its bloodUke nourishment. And Nature assigns to 

 each of the residues the part which is fitted to receive 

 it. Now the semen is a residue, and in the hotter of 

 the blooded animals, i.e., the males, this is manageable 

 in size and amount,*^ and therefore in males the parts 

 which receive this residual product are passages ; in 

 females, however, on account of their failure to effect 

 concoction, this residue is a considerable volume of 

 bloodlike substance, because it has not been matured ; 

 hence there must of necessity be here too some part 

 fitted to receive it, different from that in the male, 

 and of a fair size. That is why the uterus has these 

 characteristics ; and that is the part wherein the 

 female differs from the male.** 



We have now stated the cause why some creatures 

 are formed as males, others as females. 



And our statements are borne out by the facts. II 

 Thus : Young parents, and those which are older too, ■^^® ''^^^f^. 



c x^ ' 13 support€a 



tend to produce female offspring rather than parents by the 



facts, 

 it is all one whether we say " the semen," or " the movement 

 which causes the growth of each of the parts," or " the move- 

 ment which originally sets and constitutes the fetation." 

 Cf. 771 b 19 ff. 



' Because it is more compact ; see above, 765 b 3. 



•* Cf. 738 b 3o fF. 



395 



