SENSES OF FISHES. 7 



whereas birds, whose digestion is very rapid on ac- 

 count of their high degree of heat, cannot bear the 

 want of food for many successive hours, much less 

 days. 



Spallanzani indeed, in his curious experiments on 

 digestion, found that fishes digested more quickly than 

 serpents, and that the process was wholly effected by 

 the digestive fluid without any pressure or trituration 

 from the stomach as in birds ; for the tin tubes con- 

 taining food, which he caused eels, carp, pike, and 

 bream to swallow, were not in the least bruised, though 

 they were so thin that the slightest pressure would 

 have crushed them, while he found the food within the 

 tubes digested in the course of from one to three days. 



Like other animals, fishes discriminate the food 

 which suits them by means, of the senses of taste, 

 smell, and vision, and less commonly, I believe, by 

 hearing, each of which it may be well to notice 

 separately. 



SENSES OF FISHES. 



THE several senses are bestowed on animals to direct 

 them in the pursuit of what is beneficial, and in avoid- 

 ing what may be injurious; but for the present I 

 shall confine myself to such of them as relate to the 

 procuring of food, it being my wish to render this little 

 book as practical as possible, while, at the same time, 

 I am anxious to lay down sound scientific principles 

 upon which the practice of the art is or ought to be 

 founded. 



