T xx. 



THE OYSTER, SCALLOP, CLAM, MUSSEL, AND ABALONE INDUSTRIES. 



BY ERNEST INGEBSOLL. 



1. THE OYSTER INDUSTRY. 



1. INTRODUCTION, DEFINING AMERICAN OYSTERS. 



It is now settled that along the Atlantic coast of the United States there is only one species 

 of oyster, under the name Ostrea virginica of Gmelin. 



Great dissimilarity can often be seen when one compares two specimens of different ages, 

 or grown at localities widely separated, or in waters of unequal depth and temperature, upon 

 unlike bottoms, or under some other contrasted set of circumstances. Out of this diversity, 

 inevitable to our great extent of north and south coast line, the early naturalists were deceived 

 into naming several species, such as "borealis," " canadensis," &c., which they supposed to be dis- 

 tinct from one another ; but a more extended knowledge has shown that all these grade into one 

 another indistinguishably. " All the various forms," says Prof. A. E. Verrill, of the U. S. Fish 

 Commission, " upon which the several nominal species, united above, have been based by Lamarck 

 and others, often occur together in the same beds in Long Island Sound, and may easily be con- 

 nected together by all sorts of intermediate forms. Even the same specimen will often have the 

 form of borealw in one stage of its growth, and then will suddenly change to the mrginiana style; 

 and, perhaps, still later, will return to the form of borealis. Or these differences may be assumed 

 in reverse order." 



This eastern oyster is to be met with, almost without a break, from the northern shores of 

 the Gulf of Mexico northward to Massachusetts Bay. Beyond this it occurs only in a few almost 

 extinct beds on the coast of Maine and Nova Scotia, but reappears again in abundance in the 

 southern part of the Gulf of Saint Lawrence and around Prince Edward Island. 



On the Pacific coast, as might be expected, the oysters are different from those of the Atlantic. 

 From California northward occurs the Ostrea lurida, commonly known as the " Shoalwater Bay 

 oyster " ; while southward, even as far as Ecuador, there flourishes the little Ostrea conchophila, 

 reaching its best development in tropical waters. 



The full natural history of the species on the Pacific coast is not known. But in respect to the 

 eastern species it has been fully worked out by Mr. W. K. Brooks and Mr. John A. Ryder within the 

 past few years. All the details of the development of the egg and the growth of the young may 

 be found in the writings of these gentlemen since 1880 in the reports of the U. S. Fish Commis- 

 sion, the Maryland State Fish Commission, and the biological publications of the Johns Hopkins 

 University. The general results can only be sketched here in a single paragraph. 



It appears that among American oysters there is no distinction of sex, each individual pro 

 ducing one year either spawn (eggs) or the fertilizing milt (spermatozoa), under influences hidden 



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