46 THE HISTORY Or ANIMALS. [B. III. 



BOOK THE THIRD. 



CHAPTER I. 



1. WE have treated of the other internal parts of animals, 

 their number, their nature and varieties. It now remains for 

 us to speak of the organs of generation. In females these are 

 always internal ; but there is much difference in males, for 

 some sanguineous animals have no testicles at all, in others 

 they are internal ; and in some animals with internal tes- 

 ticles, they are placed near the kidneys, in others near the 

 abdomen ; in other animals they are external. The penis 

 of these last is sometimes united to the abdomen, in others 

 it is loose as well as the testicles ; but in promingent and 

 retromingent animals it is suspended from the abdomen 

 in a different manner. Neither fish nor any other animal 

 with gills, nor the whole class of serpents, have testicles ; 

 neither has any apodal animal which is not internally vivi- 

 parous. 



2. Birds have testicles, but they are internal and near 

 the loins, and so have oviparous quadrupeds, as the lizard, 

 tortoise, and crocodile, and among viviparous animals, the 

 hedgehog. In some viviparous animals they are situated in- 

 ternally upon the abdomen, as the dolphin among apodal 

 creatures, and the elephant among quadrupeds. In other 

 animals the testicles are external. It has been previously 

 observed, that the manner and position of their junction with 

 the abdomen is various, for in some they are joined on and do 

 not hang down, as in swine, in others they hang down as in 

 man. 



3. It has also been observed that neither fishes nor serpents 

 have testicles, but they have two passages hanging down on 

 each side of the spine from the diaphragm, and these unite 

 in one passage above the anus, by above, we mean nearer 

 the spinal column. At the season of coition these passages 

 are full of semen, which exudes on pressure ; the differences 



