GENERATION OF ANIMALS, IV. ii.-iii. 



depends upon the blend " of the surrounding air and 

 of the foods which the body takes up, and especially 

 upon the nourishment supplied by the water, since 

 this is what we take most of, water being present as 

 nourishment in everything, even in solid substances 

 as well. Hence hard, cold water in some cases causes 

 barrenness, in others the birth of females.* 



The following things are due to these same causes. Ill 

 Some offspring take after their parents and some ^„"™\o 

 do not ; some after their father, some after their parents and 

 mother, as well in respect of the body as a whole as '^°" *'"^' 

 in respect of each of the parts, and they take after 

 their parents more than after their earlier ancestors, 

 and after their ancestors more than after any casual 

 persons. Males take after their father more than 

 their mother, females after their mothor. Some take 

 after none of their kindred, although they take after 

 some human being at any rate ; others do not take 

 after a human being at all in their appearance, but 

 have gone so far that they resemble a monstrosity, 

 and, for the matter of that, anyone who does not 

 take after his parents is really in a way a mon- 

 strosity, since in these cases Nature has in a way 

 strayed from the generic type. The first beginning 

 of this deviation is when a female is formed instead of 

 a male, though (a) this indeed is a necessity required 

 by Nature,^ since the race of creatures which are 

 separated into male and female has got to be kept 

 in being '^ ; and (b) since it is possible for the male 

 sometimes not to gain the mastery either on account 

 of youth or age or some other such cause, female 



produced in the normal course of nature {aianep dvaTrrjpiav 

 <})vaiicriv). See Introd. § 13. 



"* This is an instance of a necessity required by the Final 

 Cause ; see 731 b 25—732 a 3. 



401 



