GENERATION OF ANIMALS, I. v. 



less animals. It is impossible for birds " because 

 their legs are under the middle of the abdomen. It 

 is impossible for the other creatures because they 

 have no legs at all, and that is the place where the 

 penis is always suspended and that is the position for 

 it. (This also is the reason why there is strain on the 

 legs during sexual intercourse : both the organ itself 

 and the legs are by their nature sinewy.) And so, 

 since it is impossible for them to have this organ, they 

 must of necessity have no testes either, or else not 

 have them in that place, since in those animals which 

 possess both penis and testes the situation of both is 

 one and the same. 



Another point. As far as the animals with external 

 testes are concerned, as the penis is set in movement 

 and gets heated, the semen first collects itself to- 

 gether, and then advances : it is not ready immedi- 

 ately contact is established, as it is in fishes.^ 



All the \ i\ipara have their testes in front, [or out- 

 side,*^] except the hedgehog. This is the only one 

 that has them by the loin,** and the reason is the same 

 as for the birds,*' since they must of necessity ac- 

 complish their copulation quickly, for they do not 

 mount on the back as the other quadrupeds do, but 

 on account of their spines stand upright for inter- 

 course. 



We have now said why those animals which have 

 testes have them, and why some have them outside 



' This remark, if it remains in the text, obviously cannot 

 refer to the only reason so far given for birds at 717 b 15-1,7 ; 

 if taken as referring to the reason which immediately follows, 

 this will roughly correspond to the statement in II.A. o39 b 34 

 that some birds copulate quickly. But no doubt the reason 

 Aristotle has in mind is th^ one mentioned below at 

 719 buff., viz., that the skin is too hard. 



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