^60 "WHITE SHARK. 



any use to the animal ; the other rows are a provi- 

 sion or resource against the breaking of those of the 

 outer row, and till this happens they remain flat in 

 the mouth, incapable of being erected; as soon, 

 however, as a tooth in the outer row is broken, as 

 frequently must happen, owing to the force with 

 which the animal closes his jaws, often on hard 

 bodies, the tooth immediately within becomes 

 erected, and advances forward with the line of 

 the outer row, to supply the place of that which 

 was destroyed. 



The annexed wood-cut will show the general 

 distribution of the teeth in the jaws of these vora- 

 cious fishes, and the figure on the accompanying 

 plate that of the general form adapted for rapid 

 passage through the water by a swift and gliding 

 motion, and an activity and grace in making turns 

 in pursuit of its prey. 



