INTRODUCTION. 73 



The senses among fishes may almost be said to 

 be confined to three, those of seeing, hearing, 

 and smelling, all very acute. Those of taste and 

 touch are to all appearance in subordinate 

 development, nor with the powerful exercise of 

 the others are they conducive, or necessary to 

 the existence of the individual. There is a gene- 

 ral sense of feeling by contact with any body 

 over the surface of the animal ; but unless in 

 those species which are furnished with long 

 filamentous appendages to the head, there is no 

 organ by which this property is regularly exer- 

 cised. In those fish, when lying at the bottom in 

 disturbed water, the filaments are extended, and 

 may serve to make them aware of the approach 

 of an enemy ; and among others, in the Siluri, 

 where they are of great length, and are thrown 

 out and moved, to attract attention ; from their 

 sensibility of touch, while the fish remains in 

 concealment, they may warn the lurker that his 

 prey approaches, and enable him to prepare for 

 its seizure. 



The sense of taste seems even developed in a 

 less degree, the organ in which it is generally 

 implanted being used as an accessary to prehen- 

 sion, and often armed with very strong teeth. 

 Swallowing also almost immediately follows the 

 seizure ; the prey, gorged entire, and without 

 mastication in the mouth, is rapidly dissolved and 

 digested in the stomach. 



