GENERATION OF ANIMALS, IV. vi. 



their nature ; and we should look upon the female 

 state as being as it were a deformity, though one 

 which occurs in the ordinary course of nature." WTiile 

 it is >vithin the mother, then, it develops slowly on 

 account of its coldness, since development is a sort of 

 concoction, concoction is effected by heat, and if a 

 thing is hotter its concoction is easy ; when, however, 

 it is free from the mother, on account of its weakness 

 it quickly approaches its maturity and old age, since 

 inferior things all reach their end more quickly, and 

 this applies to those which take their shape under the 

 hand of Nature just as much as to the products of the 

 arts and crafts. The reason which I have just stated 

 accounts also for the fact that (a) in human beings 

 twins survive less well if one is male and the other 

 female, but (6) in other animals they survive just as 

 well : in hiunan beings it is contrary to nature for the 

 two sexes to keep pace with each other, male and 

 female requiring unequal periods for their develop- 

 ment to take place ; the male is bound to be late or 

 the female early ; whereas in the other animals equal 

 speed is not contrary to nature. There is also a 

 difference between human beings and the other 

 animals with regard to gestation. Other animals are 

 most of the time in better physical condition, whereas 

 the majority of women suffer discomfort in connexion 

 with gestation. Now the cause of this is to some 

 extent attributable to their manner of life, which is 

 sedentary, and this means that they are full of resi- 

 due ; they have more of it than the other animals. 

 This is borne out by the case of those tribes where 

 the women live a life of hard work. With such women 

 gestation is not so obvious, and they find deUvery an 

 easy business. And so do women everywhere who 



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