GENERATION OF ANIMALS, IV. i. 



possess no testes — as is the case with the animals 

 that have no feet, e.g., the tribes of fishes and 

 serpents." 



Now the opinion that the cause of male and female 

 is heat and cold, and that the difference depends upon 

 whether the secretion comes from the right side or 

 from the left, has a modicum of reason in it, because 

 the right side of the body is hotter than the left ^ ; 

 hotter semen is semen which has been concocted ; 

 the fact that it has been concocted means that it has 

 been set and compacted,*^ and the more compacted 

 semen is, the more fertile it is.** x\ll the same, to 

 state the matter in this way is attempting to lay hold 

 of the cause from too great a distance, and we ought 

 to come as closely to grips as we possibly can \\"ith 

 the primary causes.* 



• We have dealt already elsewhere ^ with the body as The ftmda- 

 a whole and with its several parts, and have stated ™i3°^etion 

 what each one is, and on account of what cause it is betweon 

 so. But that is not all, for (1) the male and the "^4"^ 

 female are distinguished by a certain ability '' and 

 inability.* Male is that which is able to concoct, to 

 cause to take shape, and to discharge, semen ' 

 possessing the " principle " of the " form " ; and by 

 " principle " I do not mean that sort of principle out 

 of which, as out of matter, an offspring is formed 

 belonging to the same kind as its parent, but I mean 

 the Jirst motive principle, whether it is able to act 

 thus ' in itself or in something else. Female is that 

 which receives the semen, but is unable to cause 



* Thus much has already been stated at 716 a 18 ff., but 

 Aristotle now develops it more fully. 



• With this passage cf. the discussion at 72i a 29 ff. 

 ' i.e., act as the cause of movement. 



O 385 



