CLASS IV. PISCES. 2515 



and the flexibility of their members gives them a velocity 

 superior to that of any product of human ingenuity. 



Fins are the principal auxiliaries of motion ; and a fish 

 completely equipped is furnished with two pair, and three 

 single fins, two above and one below. Thus provided, 

 it moves with the utmost rapidity, and can undertake the 

 longest voyages ; but those fishes which have the greatest 

 number of fins are not always the swiftest ; as is evident 

 in the shark, which is. destitute of ventral fins. 



Not only is progression forwarded by these appendages, 

 but they likewise assist in the action of rising and sinking, 

 turning, or even leaping out of the water ; and it is curi- 

 ous to observe how every pair of fins, and even every 

 single fin, contributes to some appropriate end. The pec- 

 toral fins serve to balance the head of the animal, the 

 dorsal to keep it in equilibrium, and the anal to preserve 

 the upright or vertical situation. The size of these mem- 

 bers is also wonderfully adapted to the conformation of 

 the body, and to facilitate all its actions. 



Terraqueous animals, as has been shown before, are ge- 

 nerally furnished with coverings to keep off the injuries 

 of the weather ; and for the tenants of the deep there is 

 a no less advantageous provision. They are covered in 

 the first place with a slimy glutinous fluid ; which defends 

 their bodies from immediate contact with the surrounding 

 water, and lubricates their passage. Beneath this, in 

 many kinds, is found a strong covering of scales; and 

 under that an oily substance is lodged, which supplies the 

 requisite warmth and vigour. 



Thus, in comparing their respective situations, we find 

 the fish as well furnished with the means of happiness as 

 the quadruped ; but if we regard their faculties, the for- 

 mer is certainly much inferior. The sense of feeling, so 

 exquisite in men and quadrupeds, can be but imperfect 

 in the fish. The sense of smell they enjoy in a very li- 

 mited degree ; in that of taste they appear very defective ; 

 and their hearing is still more imperfect, if it exists at all. 

 Indeed this last sense would be useless to creatures that 



