26 NATURALIST'S CABINET. 



On the teeth of fish. 



on the inside as is supposed to be the case in 

 quadrupeds ; I should therefore very much sus- 

 pect that the lining of those tubes in the qua- 

 druped is not nerve, but a kind of internal pe- 

 rioesteum." 



Whether every species of fish be endued with 

 the organ* of hearing, especially those which are 

 deprived of eyes, as oysters, muscles, and all tes- 

 taceous fish with hard shells., certainly admits 

 of doubt : for though in some instances they 

 contract and shut themselves up within their 

 cells, this seems to be operated less by the sense 

 of hearing, than by that of feeling, which the 

 water may excite. 



Although aquatic animals possess teeth, they 

 are not calculated for breaking the food into 

 small morsels, but rather to grasp their prey, and 

 hinder the creatures they have once caught from 

 escaping again; they feed chiefly on smaller li.xh, 

 or other animals that need no tritu ration in the 

 mouth, but spontaneously and gradually dissolve 

 into a liquid chyle ; there are also two round 

 bodies in the posterior part of the jaws, which, 

 as well as the basis of the bronchi, have a number 

 of tenter-hooks fixed in them in such a manner, 

 as that any thing can easily get down, but is hin- 

 dered from returning. 



Tish not having any thing that can be called 

 a neck, the oesophagus, or gullet, is of course 

 very short, and scarcely distinguished from the 

 stomach; for in fact the food lies equally in 



