FISHES IN GENERAL. 231 



this bj experiment, a carp is taken, and put into a large vessel. The 

 fish, in a state of repose, spreads all its fins, and seems to rest upon 

 its pectoral and ventral fins near the bottom : if the fish folds up, (for 

 it has the power of folding) either of its pectoral fins, it inclines to 

 the same side ; folding the right pectoral fin, the fish inclines to the 

 right side ; folding the left fin, it inclines to that side in turn. When 

 the fish desires to have a retrograde motion, striking with the pecto- 

 ral fins, in a contrary direction, effectually produces it. If the fish 

 desires to turn, a blow from the tail sends it about ; but if the tail 

 strikes both ways, then the motion is progressive. In pursuance of 

 these observations, if the dorsal and ventral fins be cut off, the fish 

 reels to the right and left, and endeavours to supply its loss by keep- 

 .ng the rest of its fins in constant employment. . If the right pectoral 

 fin be cut off, the fish leans to that side ; if the ventral fin on the 

 same side be cut away, then it loses its equilibrium entirely. When 

 the tail is cut off, the fish loses all motion, and gives itself up to where 

 the water impels it. 



From hence it appears that each of these instruments has a pe- 

 culiar use assigned it ; but, at the same time, that they all conspire 

 to assist each other's motions. Some fish are possessed of all, whose 

 motions are yet not the swiftest ; others have but a part, and yet dart 

 in the water with great rapidity. The number, the size, and the 

 situation of the fins, therefore, seem rather calculated to correspond 

 with the animal's figure, than solely to answer the purposes of pro- 

 moting its speed. Where the head is large and heavy, there the pec- 

 toral fins are large, and placed forward, to keep it from oversetting. 

 Where the head is small, or produced out into a long beak, and there- 

 fore not too heavy for the tail, the pectoral fins are small, and the 

 ventral fins totally wanting. 



As most animals that live upon land are furnished with a covering 

 to keep off the injuries of the weather, so all that live in the water 

 are covered with a slimy, glutinous matter, that, like a sheath, de- 

 fends their bodies from the immediate contact of the surrounding 

 fluid. This substance may be considered as a secretion from the 

 pores of the animal's body, and serving not only to defend, but to as- 

 sist the fish's easy progress through the water. Beneath this, in many 

 kinds, is found a strong covering of scales, that, like a coat of mail, 

 defend it still more powerfully ; and under that, before we come to 

 the muscular parts of the body, an oily substance, which supplies the 

 requisite warmth and vigour. 



The fish, thus protected and fitted for motion in its natural ele- 

 ment, seems as well furnished with the means of happiness as quad- 

 rupeds or birds ; but if we come to examine its faculties more nearly, 

 we shall find it very much their inferior. The sense of touching, 

 which beasts and birds have in a small degree, the fish, covered up 

 in its own coat of mail, can have but little acquaintance with. 



The sense of smelling, which in beasts is so exquisite, and among 

 birds is not wholly unknown, seems given to fishes in a very moderate 

 proportion. It is true, that all fishes have one or more nostrils ; and 

 even those that have not the holes perceptible without, yet have the 

 proper formation of the bones for smelling within. But as air is the 

 only medium we know for the distribution of odours, it canno' DB 



