GENERATION OF ANIMALS, 1. xx. 



were a fetation.** (By fetation I mean the primary 

 mixture of male and female.) This explains inci- 

 dentally why one body only is formed from one 

 seed — e.g., one stalk from one grain of corn, just 

 like one animal from one egg (double-yolked eggs of 

 course count as two eggs). In those groups, however, 

 where male and female are distinct, many animals 

 may be formed from one semen, which suggests that 

 the nature of semen in animals differs from that in 

 plants.^ We have as a proof of this those animals 

 which are able to produce more offspring than one at 

 a time, where more than one are formed as the result 

 of one act of coitus. This shows also that the semen 

 is not drawn from the whole body ; because we 

 cannot suppose (a) that at the moment of discharge • 

 it contains a number of separate portions from one 

 and the same part of the body ; nor (b) that these 

 portions all enter the uterus together and separate 

 themselves out when they have got there.'' No ; 

 what happens is what one would expect to happen. 

 The male provides the " form " and the " principle 

 of the movement," ^ the female provides the body, 

 in other words, the material." Compare the coagula- 

 tion of milk. Here, the milk is the body, and the 

 fig-juice or the rennet contains the principle which 

 causes it to set.^ The semen of the male acts in the 

 same way as it gets divided up into portions within 

 the female. (Another part of the treatise^ will 

 explain the Cause why in some cases it gets divided 

 into many portions, in others into few, while in others 

 it is not divided up at all.) But as this semen which 

 gets divided up exhibits no difference in kind, all that 



Cf. 739 b 23. 

 ' 771 b 14 ff. 



109 



