128 FINS OP PISH. 



LESSON XXIV. 



PINS OP PISH AIR-BLADDER ELECTRIC PISH. 



THE provision made to enable fish to move 

 in the water is very beautiful ; this consists of 

 parts called fins ; and these serve the same pur- 

 poses as the wings of birds, and the legs and arms 

 of the mammalia. The situation of these fins upon 

 the body, and their number, vary according to 

 the habits and species ; the common trout having 

 eight, two on the back, two on the breast, two on 

 the under part of the body, and two single ones ; 

 whilst the common eel Jias no fins on the breast. 

 In the haddock, the fins, which in the trout are 

 placed on the breast, are fixed on the throat ; 

 and in the perch, the same fins are fixed close 

 to the pectoral or breast-fins. The fins differ 

 greatly in size, and are made up of bony spines, 

 connected together by a membrane, and are 

 moved by strong muscles, just in the same way 

 as the wings of birds and our arms. By means 

 of these fins, the fish, which may be said to be 

 suspended in the water, can move in all direc- 

 tions easily and with great velocity. Many fish, 

 which feed partly on insects, can leap to a consi- 

 derable height out of the water in pursuit of 

 them. This is done by means of the tail, which 

 is reckoned as a fin, and is also used as a rudder 

 to direct their motions. In manjr instances this 



