ARTIFICIAL OYSTER CULTURE. 1 067 



bed, with a few medium-sized oysters and very great num- 

 bers of young, and the bottom, which had been rather 

 soft, had become quite hard ; in fact, the spot presented 

 all the characteristics of a natural bed. Changes of this 

 sort are a matter of familiar experience, and it is plain that 

 something else besides the absence in the oyster of loco- 

 motive power determines the size and position of a bed. 



Now what is this something else ? If the planting of 

 dead shells will build up a new bed, may we not conclude 

 that a natural bed tends to retain its position and size 

 because the shells are there ? This conclusion may not 

 seem to be very important, but I hope to show that it is 

 really of fundamental importance, and is essential to a 

 correct conception of the oyster problem. Why should 

 the presence of shells, which are dead and have no power 

 .to multiply, have anything to do with the perpetuation of 

 a bed ? 



. . . . The young oysters feed upon the floating 

 organic matter which is brought to them by the water, and 

 this food is most abundant where the water flows in a 

 strong current over soft organic mud, When the bottom 

 is hard there is little food, and this little is not favourably 

 placed for diffusion by the water, while the water which 

 flows over soft mud is rich in food. . . . The young 

 oysters which settle upon or near a soft bottom are there- 

 fore most favourably placed for procuring food. . . . 

 and have the habit of fastening themselves to solid bodies, 

 such as shells, rocks or piles, or floating bodies, whereby 

 they are enabled to profit by the soft bottoms without 

 danger. 



Owing to the peculiar shape of an oyster shell, some 

 portions usually project above the mud long after most of 

 it is buried, and its rough surface furnishes an excellent 



