. Essentials of biology presented in problems. Biology. THE MOLLUSKS 2S9 tiflcially, stakes or brush are sunk in shallow water so that the young oyster, which is at first free-swimming, may escape the danger of smoth- ering on the bottom. After the oysters are a year or two old, they are taken up and put down in deeper water as seed oysters. At the age of three and four years they are ready for the market. The oyster industry is one of the most profitable of our fisheries. Nearly S65,000,000 a year has been derived during the last decade from suoh sources. Hundreds of boats and thousands of me
. Essentials of biology presented in problems. Biology. THE MOLLUSKS 2S9 tiflcially, stakes or brush are sunk in shallow water so that the young oyster, which is at first free-swimming, may escape the danger of smoth- ering on the bottom. After the oysters are a year or two old, they are taken up and put down in deeper water as seed oysters. At the age of three and four years they are ready for the market. The oyster industry is one of the most profitable of our fisheries. Nearly S65,000,000 a year has been derived during the last decade from suoh sources. Hundreds of boats and thousands of men are engaged in dredging for oysters. Three of the most important of our oyster grounds are Long Island Sound, Narragansett Bay, and Chesapeake Bay. Sometimes oysters are artificially " fattened " by placing them on beds near the mouths of fresh-water streams. Too often these streams are the bearers of much sewage, and the oyster, which lives on microscopic organ- isms, takes in a number of bacteria with other food. Thus a person might become infected with the typhoid bacillus by eating raw oysters. It is evident that state and city supervision ought to be exercised with refer- ence not only to the sale of shellfish which comes from contaminated localities, but also to prevent the growth of oysters or other moUusks in the neighborhood of the openings of sewers or sewage-bearing rivers. / Clams. — Other bi- valve mollusks used for food are clams and scal- lops. Two species of the former are known to New Yorkers, one as the " round," another as the "long" or "soft- shelled " clams. The former {Venus merce- neria) was called by the Indians " quahog," and is stUl so called in the Eastern states. The blue area of its shell was used by the Indians as wampum, or money. The quahog is now ex- tensively used as food. The "long" clam (Mya arenaria) is considered better eating by the inhabitants of Massa- chusetts and Rhode Isl
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbiology, bookyear1911
