236 Our Food Mollusks 



river bottoms there have never been, under natural con- 

 ditions, any such bodies that might afford attachment, 

 and thus serve as a nucleus for oyster growth. Along 

 the north coast are stones, and gravel, and the shells of 

 mollusks; and about the Mississippi delta, vast numbers 

 of shells of two or three species of small bivalves that 

 inhabit the mud, came naturally, in certain localities, to 

 lie on the surfaces of the softest bottoms. On these, 

 natural beds became established. 



There are very extensive oyster beds on the banks of 

 these small bays or rivers. Because they are exposed at 

 low water, these oysters could easily be gathered. As a 

 matter of fact, they are seldom disturbed, for they are 

 not marketable. They have been used as a fertilizer, 

 and burned for the lime in their shells. A few of the 

 oyster establishments occasionally succeed in disposing 

 of them in cans, but from the commercial point of view 

 they are almost valueless on account of their small size, 

 elongated form, and poor condition. 



To one who has seen oysters only from artificial beds, 

 where they lie spread out in an even layer, these present 

 a strange appearance. What first attracts attention is 

 that they are in clusters of various sizes. If one were 

 to attempt to lift a cluster from the bank, he would find 

 that its base extended down into the mud so deep as to 

 afford a secure anchorage. A vigorous pull may dis- 

 lodge the whole mass, though the lower part of it may be 

 buried under many inches of soft mud. It will then be 

 discovered that the cluster of living oysters that was ex- 

 posed above the bottom, is firmly attached to a number 

 of empty oyster shells below them, the whole being fused 

 into a compact mass. The shells of living and dead 

 oysters thus bound together may number scores. 



