OP FISHES. 55 



prismatic cornea. On the other hand, the whole 

 globe is so raised upon the top of the head, that 

 without this structure, they would, perhaps, only 

 distinguish objects that were on a level with the 

 base of the orbit ; a defect, admitting such to be 

 the fact, completely obviated, by giving the cornea 

 an acute angle across its horizontal centre — al- 

 lowing the rays of light, from the angle subtended 

 by the planes of the two corneas, to reach the re- 

 tina from two directions, nearly perpendicular to 

 the horizon. Some have imagined that the one 

 pupil was long-sighted, for distant views, and the 

 other short-sighted, for minute objects. 



THE EYE OF THE ANABLEPS TETROPHTHALMUS. 



Fishes are acutely sensible of touch ; — the 

 sense of smelling, for which appropriate nerves 

 are elaborately distributed, gives them the faculty 

 of detecting the existence of food, or enemies, at 

 immense distances. Taste is undoubtedly the 

 weakest of their senses, — residing, if at all, in 



