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of motion, to which the fins are only subservient. 

 This is easily ascertained if we put a fish into a 

 large vessel of water. When in a state of repose, 

 it will be seen to spread out all its fins, and to 

 rest near the bottom on the pectoral and ventral ; 

 and, if it fold up either of its pectoral fins, it will 

 incline to the side on which the folding takes 

 place. When it desires to have a retrograde 

 motion, striking with the pectoral fins in a con- 

 trary direction, effectually produces it. If it de- 

 sires to turn, a blow from the tail sends it about; 

 but if the tail strike both ways the motion is pro- 

 gressive. If the dorsal arid ventral fins be cut 

 off, the fish reels to the right arid left, and endea- 

 vours to supply the loss by keeping the rest of 

 its fins in constant motion. If the right pectoral 

 fin be removed, the fish leans to that side ; arid if 

 the ventral fins on the same side be cut away, it 

 entirely loses its equilibrium. When the tail is 

 removed the animal loses all power of motion, 

 and abandons itself to the impulse of the water. 

 Fishes, however, that have the greatest num- 

 ber of fins have not always the swiftest motion. 

 The haddock, with its full set of fins, is very slow 

 and tardy, while the shark, which wants the ven- 

 tral fin, is the swiftest swimmer. Again, not- 

 withstanding their agility arid swiftness, fishes 

 often remain in a state of inactivity and supine- 

 ness, until aroused by the dread of an approach- 

 ing enemy, or the calls of hunger. But it is not 

 only by their swiftness that fishes are enabled to 

 avoid danger and destruction. Another great 



