AMPHIBIOUS QUADRUPEDS. 



and that more freely the longer the operation is 

 continued ; so that, at last, when the bat goes off, 

 the blood continues to flow. In confirmation of 

 this opinion we are told, that where beasts have 

 a thick skin, this animal cannot injure them ; 

 whereas, in horses, mules, and asses, they are 

 very liable to be thus destroyed. As to the rest, 

 these animals are considered as one of the great 

 pests of South America, and often prevent the 

 peopling of many parts of that continent, having 

 destroyed at Barja, and several other places, such 

 cattle as were brought there by the missionaries 

 in order to form a settlement. 



CHAPTER VIII. 



. 



OF AMPHIBIOUS QUADRUPEDS. 



THE gradations of nature from one class of beings 

 to another are made by imperceptible deviations. 

 As we saw in the foregoing chapters quadrupeds 

 almost degraded into the insect tribe, or mounted 

 among the inhabitants of the air, we are at present 

 to observe their approach to fishes, to trace the 

 degrees by which they become more unlike ter- 

 restrial animals, till the similitude of the fish pre- 

 vails over that of the quadruped. 



As in opposite armies the two bodies are dis- 

 tinct and separated from each other, while yet 

 between them are various troops that plunder on 



