64 THE OYSTER, 



lous bodies in the universe. Elsewhere we have com- 

 plex results from complex means, but here we have 

 the most complex of all things, a living body, arising 

 without any visible machinery. 



Even after the cells which result from the multipli- 

 cation of the ^^% cell become pretty numerous and 

 begin to shape themselves into a complicated body, 

 this at first bears no close resemblance to an oyster, 

 and while the ultimate outcome is an oyster like the 

 parent, I should give my readers a very incomplete 

 and erroneous picture of the history of its develop- 

 ment if I did not lay stress upon the very remarkable 

 fact that this result is not reached directly. 



The mature oyster is a sedentary animal with no 

 power of locomotion. It lies on its side, soldered to 

 the bottom by the outside of the deep spoon-shaped 

 left shell, for w^hich the flat right shell forms a mova- 

 ble lid. Its gills are very complicated organs, adapted 

 for drawing into the fixed shell a steady current of 

 water, and they pour into the open mouth of the animal 

 a constant stream of food, so that eating goes on as un- 

 interruptedly as breathing, and is just as much beyond 

 the control of the animal. The adult oyster makes 

 no efforts to obtain its food, it has no way to escape 

 from danger, and after its shell is entered it is per- 

 fectly helpless and at the mercy of the smallest enemy. 

 So far as active aggressive life goes it is almost as 

 inert and inanimate as a plant, and its life is purely 

 vegetative. This is the adult oyster. The young 

 oyster is very different. It is an active animal, swim- 

 ming from place to place. Its gills are not leaf-like, 

 and they do not divide the mantle-chamber into two 



