204 



|r I S H £ S; IN GENERAL. 



that fide : folding the right peroral fin, thefifli inclines to the right fide; 

 folding the left fin, it inclines to the left fide. If the fifh defires a retro- 

 grade motion, ftrikingwith the pe£toral fins, in a contrary diredlion, pro- 

 duces it. If the fiih defires to turn, a blow from the tail turns itj but if 

 the tail ftrike both ways, the motion is progrefiive. In purfuance of 

 thefe obfervations, if the dorfal and ventral fins be cut off, the fi(h reels 

 to right and lefc, and endeavours to fupply the lofs by keeping the reft of 

 its fins in conftant employment. If tlie right pefloral fin be cut off, the 

 filh leans to that fide; if the ventral fin on the fame fide be cutaway, then 

 itlofes its equilibrium entirely. When the tail is cut off, the filh lofes all 

 motion, and gives itfelf up to where the water impels it. Each of thefe 

 fins has its peculiar ufe; but all confpire to affift each others motions. 

 Some fifii are poffeffed of all, whofe motions are yet not the fwifteft. Their 

 number, fize, and fituation, feem calculated rather to correfpond with 

 the animal's figure, than folely to anfwer the purpofes of fpeed. Where 

 the head is large and heavy, the peroral fins are large and forward. 

 Where the head is fmall or long, the pedloral fins are fmall, and the ven- 

 tral fins wanting. 



Inhabitants of the water are covered with a flimy glutinous matter 

 (a fecretion from the animal's body), that defends their bodies from 

 the immediate contadof the furrounding fluid, and contributes to their eafy 

 progrefs through the water. Beneath this, in many kinds, is a ftrong 

 covering of fcales, a ftill more powerful defence ; and under that, before 

 we come to the mufcular parts of the body, an oily fubftance, which fup- 

 plies, or rather which includes, the requifite warm.th. 



Islature feems to have beftowed on thefe animals appetites and powers 

 of inferior kinds. Formed for paffive exiftence in their obfcurc and heavy 

 element, to preferve this exiftence, and to tranfmit it, is their whole 

 purfuit and enjoyment. Impelled rather by neceffity than choice, and me- 

 chanically excited to every fruition, they chafe without diftindion what- 

 ever they can fwallow, conquer, or enjoy. 



A ceafelefs defire of food feems their ruling impulfe, and prompts 

 them to encounter every danger. Their rapacity feems infatiable. Even 

 when taken out of the water^ and almoft expiring, they greedily fwallow 

 the very bait by which they were allured to deftruftion. 



The maw is, in general, placed near the mouth; and, though poffeffed 

 6f no fenfible heat, is however endued with a furprifing faculty of di- 

 geftion, fecming in fome meafure to increafe with the quantity of food. 

 It digefts not only fifh, but prawns, crabs, and lobfters, fliells and all; 

 though thefe Ihclls are fo much harder than the fides of the ftomach 



whiclv 



