OYSTERS AND METHODS OF OYSTER-CULTURE. 293 



they are discharged into the water ia countless numbers, to be swept away to great 

 distances by the currents. As they are too small to be seen at this time without a 

 microscope it is impossible to trace their wanderings directly, but it is possible to 

 show indirectly that they are carried to great distances and that the water for miles 

 arouud the natural bed is full of them. They serve as food for other marine auimals, 

 and when the contents of the stomachs of these animals are carefully examined with 

 a microscope the shells of the little oysters are often found in abundance. While 

 examining the contents of the stomach of lingula in this way I have found hundreds 

 of the shells of the young oysters in the swimming stage of growth, although the 

 specimens of lingula were captured several miles from the nearest oyster-bed. As 

 lingula is a fixed animal the oysters must have been brought to the spot where the 

 specimens were found, and as the lingula has no means of capturing its food, aud 

 subsists upon what is swept within its reach by the water, the i)resence of so many 

 inside its stomach shows that the water must have contained great numbers of them. 



It is clear, theu, that the sharp limitation of the area of a natural oyster bed is not 

 due to the al)seuco in the young of the power to reach distant points. There is 

 another proof of this, which is familiar to all oystermen — the possibility of estab- 

 lishing new beds without transplanting any oysters. The following illustration of 

 this was observed by one of your commissioners : On part of a large mud flat which 

 was bare at low tide there were no oysters, although there was a natural bed upon 

 the same flats, about half a mile away. A wharf was built from high-tide mark 

 across the flat out to the edge of the channel, and the shells of all the oysters which 

 were consumed in the house were thrown onto the mud alongside the wharf. In the 

 third summer the flat in the vicinity of the wharf had become converted into an 

 oyster-bed, with a few medium-sized oysters and very great numbers 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, aud it is plain that something else besides the absence 

 in the oyster of locomotive 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 import- 

 ant, but I hope to show that it is really of fundamental importance and is essential 

 to a correct conceiition 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? 



We have already called attention to the fact that oysters are found on the hard 

 bottom on each side of the channel, while they are not found in the soft mud of the 

 channel itself, and it may at first seem as if there were some direct connection 

 between a hard bottom and the presence of oysters, but the fact that no oysters are 

 found upon the hard, firm sand of the ocean beach shows that this is not the case. 

 As a matter of fact, they thrive best upon a soft bottom. They feed upon the floating 

 organic matter which is brought to them by the water, and this food is most abun- 

 dant 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 favorably placed for diti'usion 

 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 therefore most 

 favorably placed for procuring food, but the young oyster is very small — so small 

 that a layer of mud as deep as the thickness of a sheet of paper would smother and 

 destroy it. Hence the young oysters have the habit of fastening themselves to solid 

 bodies, such as shells, rocks, or i)iles, or floating bushes, and 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 

 basis for attachment. It forms one of the very best supports for the young, and a 

 little swimming oyster is especially fortunate if it finds a clean shell to adhere to 

 when it is ready to settle down for life. Then, too, the decaying and crumbling 



