GENERATION OF ANIMALS, I. xii.-xni. 



hand as against birds and o\"iparous quadrupeds on 

 the other ; and then again it is different in those 

 aniniak which produce their young by both of the two 

 methods, \'iz., which are internally o\iparous and out- 

 wardly \'i\i parous. Those animals which are both 

 internally and externally vi\iparous have their uterus 

 placed against the abdomen, as for iastance man, ox, 

 dog, and other such animals, since it is expedient for 

 the safety and growth of the embryo that no weight 

 should be put upon the uterus.] 



In all these animals the passage through which the XIII 

 solid residue issues is other than that through which 

 the fluid issues. On this account all such animals, 

 both male and female, have pudenda by which the 

 fluid residue is voided, and thereby too in males the 

 semen passes out and in the females the fetation.** 

 This passage is situated higher up than the passage 

 for the solid nourishment and in front of it. '' [Those 

 animals which lay eggs, but lay imperfect ones, e.g., 

 the o\"iparous fishes, have their uterus not under the 

 abdomen but by the loin, since the growth of the egg 

 causes no obstruction, because the groAnng object 

 icomes to its perfection and makes its advance outside 

 Ithe animal.] In all those animals which have no 

 pudendum which serves for generation, this passage 

 is the same as that for the solid nourishment, \-iz., 

 in all the 0\ipara, including those 0\ipara which 

 have a bladder, e.g., the tortoises. The existence of 

 tno passages, it must be remembered, is for the sake 

 of generation, not for the sake of voiding the fluid 

 residue, and it is only because the semen is fluid in 



" See Introd. § 56. 



* This sentence is a continuation of the previous inter- 

 polation. 



39 



