4 THE HABITS AND HAUNTS OF FISH. 



rays. Refraction enables the fish to see an approach- 

 ing or moving object, even when a projecting bank 

 or overhanging rock or other substance intervenes. 

 Mr. Ronalds illustrates this by a familiar scientific 

 experiment with a coin and vessel of water, by which 

 the former, when placed in the bottom of the latter, 

 is seen at an acute angle, when the side of the vessel 

 intercepts a straight line between the coin and the 

 eye of the spectator. We have known persons who 

 have domesticated trout, being unacquainted with 

 the laws of refraction, who have attributed this to 

 various other causes. 



SENSE OF HEARING. That trout are not wholly 

 devoid of this sense is now a well established axiom. 

 There is nothing about the exterior of the head of 

 a fresh-water fish that would indicate that it is pro- 

 vided with an ear. Our leading physiologists and 

 anatomists assert, nevertheless, that fish and other 

 aquatic creatures have the internal organ in a state 

 of perfection. In animals of higher grade the 

 mechanical apparatus of hearing consists of two con- 

 nected portions, external and internal. Fish appear 

 to have the internal part, which is in direct com- 

 munication with the brain. The organs of hearing 

 possessed by terrestrial animals are designed for the 

 reception of the more delicate vibrations of the 

 atmosphere, whilst those of the fish are better adapted 

 to the stronger pulsations of a denser element. Thus, 

 though the inhabitants of the waters are insensible 

 to atmospheric sound, they are very susceptible to 

 vibrations of the earth which are communicated to 



