24 r/^^ BRITISH ANGLER. 



and growing always fomewhat taper at the 

 Head, enables them to traverfe the Water. 

 The Tail, by the Afllftance of the Mufcles, 

 is exceedingly pliant, ftrong, and adive ; in- 

 clines to the Right and Left, and, when re- 

 duced to a dired Line, repels the Water that 

 lies behind it : Immediately it refumes its play- 

 ing, and, by this alternate Motion, advances 

 the Head, and in fhort the whole Body, in a 

 much more agreeable Manner than an Oar, 

 work'd alternately to and fro at the Stern of a 

 Boat, conveys it up a River. The Fins, which 

 lie under the Fifh's Belly, are fometim.es of 

 fingular Service ; not only in repelling the 

 Water, and advancing the Body ; but in {top- 

 ping its Courfe, when they are extended, and 

 lie at reft. Their peculiar Office, however, 

 is to direct the Movement of the Body, by 

 keeping it in an equal Foife \ fo that in Cafe 

 the Fifh fhould only move the Fins on its 

 right Side, and bring thofe on its Left clofe 

 to its Body, all the Motion is in an Inftant 

 determined to that Side : Juft as a Boat, that 

 has two Oars, when but one is made ufc of, 

 will infallibly turn to that Side whereto it is 

 impelled by the Working of the other. If 

 you cut off a Filh's Fins, the Back, which 

 is heavier than the Belly, being no longer in 

 an Equilibrium, will either lie aflant, or be 

 turned dire6lly up ; as is the Cafe with dead 

 Fiih, whofe Fins lie always on the Surface 

 of the Water. 



If 



