AMONG THE DISHES. 



125 



his body displaces. Not so with the fish. Its weight 

 is much more nearly as light as the water in which it 

 swims. Then there is the swimming bladder, which 

 young fishers find within the fish, lying just under the 

 backbone. This connects with the mouth, and is 

 filled with air or emptied, at the will of the fish. Hence 

 it is quite easy for the finny creature to rise or drop 

 in the water, and to stand still, with little or no mo- 

 tion of the fins. 



A common river-chub must be called up here that 

 the names of fins and other parts may be learned. 

 Behind the head are the pectoral fins (//), one on 



Fig. 11. Common Chub. 



each side. Still further back and below are the ventral 

 fins(>/), another pair. These pectoral and ventral fins 

 correspond to the arms and legs of human creatures, or 

 to the fore and hind legs of quadrupeds. On the back 

 is the dorsal fin (df\ Some fishes have two dorsal 

 fins. On the under side near the tail hangs the anal 

 fin (af). Then comes the tail, or caudal fin (<:/). 



The pectoral and ventral fins enable the fish to bal- 

 ance itself so as not to turn over on its side. The 

 dorsal and anal fins keep it in a straight line when it 

 moves, while the tail fin is the oar or scull, which 

 works from side to side, and makes the fish go. The 



or THK 



UNIVERSITY 



