So THE PHILOSOPHY 



With regard to internal ftrudure, fifhes, like land-animals, are 

 furniflied with a back -bone and ribs, which run from the head to 

 the tail. To thefe, the bones of the head, and the fins, all the rauf- 

 cles and Inftruments of motion, are attached. 



The mouths of moll fifhes are furnifhed with teeth ; but in fome, 

 as the mullet, fturgeon, &c. the teeth are wanting. In fome, the 

 teeth are fituated on the jaw-bones, in others, on the tongue and 

 palate. The teeth of fifhes are principally defigned for laying hold 

 of and detaining theii prey, which they generally fwaliow entire. 

 For this purpofe, the teeth are commonly ferrated, or bent inward, 

 like tenter- hooks. By this ftrudlure, fmall fifhes are eafily forced 

 downwards, and their return is at the fame time prevented. 



In fifhes, the organ of fmelling is large ; and they have a power 

 of contradting and dilating, at pleafure, the entry into their nofe. 



It was formerly doubted whether fifhes were endowed with the 

 fenfe of hearing. But that doubt is now fully removed; becaufe it 

 has been found, that, like other animals, they have a complete or- 

 gan of hearing, and that water is a proper medium for the convey- 

 ance of found. Befides, in the Ikate, and fome other genera, the 

 learned and ingenious Dr Monro, ProfefTor of Anatomy in the Col- 

 lege of Edinburgh, has lately difcovered an aperture which leads 

 diredly to the internal parts of the ear. 



The gullet of fifhes is fo fhort that it is hardly to be diftinguifhed 

 from the ftomach, which is of an oblong figure. The guts are very 

 fliort making only three convolutions, the laft of which terminates 

 in the common vent for the faeces, urine, and femen. From this 

 ftruifture of the ftomach and inteftines, analogy would lead us to 

 conclude, that fifhes live chiefly upon animal food. Experience, ac- 

 2 cordingly, 



