THE STRUCTURE OF THE OYSTER. 79 



The ocean teems with life. But how can the oyster 

 avail itself of the plenteous banquet ? Other creatures go 

 hither and thither at pleasure. The lion roams the forest, 

 the eagle soars aloft on mighty wing, the fish glides gently, 

 or darts rapidly through the waters, and the dragon-fly 

 passes with a brilliant flash through the air, each one to 

 rejoice in the seizure of its prey. There are limes and 

 scallops, too molluscs like the oyster which are called 

 " the butterflies of the ocean," not only from the delicacy 

 and beautiful colouring of the wing--like shell, but also from 



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their agile motions. It is only for one of these creatures 

 to open the valves of its shell and suddenly to close them, 

 and it so discharges the water that the lime or the scallop 

 is impelled onwards or upwards. When this force is spent 

 it repeats the operation, thus taking long and rapid leaps, 

 and shooting hither and thither in an irregular and zigzag 

 course. 



But the oyster is not thus gifted with the power of 

 flight, or even of motion. It remains day after day, week 

 after week, month after month, it may be year after year, 

 fixed where it was, and has no more ability of transition to 

 another spot, even at the distance of an inch than the rock 

 itself. 



The oyster has not even a tongue, which is granted to 

 some little creatures, as the trochus or common top. This 

 tongue, is, in fact, an extremely delicate ribbon, of a 

 transparent substance, on which teeth are placed, of a 

 texture glassy and brilliant. These teeth are arranged in 

 three rows : the middle ones being three-pointed, while in 

 the two other rows there is the alternation of a three- 

 pointed tooth with a larger one, which has a somewhat 

 boat-like appearance. As the teeth project from the 

 surface of the tongue in hooked curves, and all point in 



