48 LECTURE VIII. 



called the crystalline humour, is of a round or glo- 

 bular shape, in order to give the animal the ne- 

 cessary power of vision, and to compensate for 

 the comparative flatness of the cornea. 



The organ of smelling in fishes is large, and 

 the animals have the power of contracting or di- 

 lating the passage to it at pleasure. Their smell 

 is supposed to be extremely acute. 



It was formerly much doubted whether fishes 

 possessed the sense of hearing, having no external 

 ear : the accurate researches of modern anatomists 

 have however clearly evinced that the organ of 

 hearing, though differing in some particulars from 

 that of other animals, does yet exist ; and is only 

 modified according to the different nature of the 

 animals. Indeed although the nature of the organ 

 of hearing in fishes was not accurately known to the 

 older anatomists, yet it was plain that fishes did 

 hear ; as was evident from a practice common 

 in many parts of Europe of calling Carp and other 

 fishes to their feeding-place by the sound of a 

 bell; a signal which the animals readily obey. 

 The particular structure of the Ear in fishes may 

 be found amply explained in the works of Monro, 

 .Cuvier, Camper, and other modern anatomists. 



Of voice, properly so called, fishes are en- 



