64 THE SCALLOP FISHERY 



distance by either wind or tide, and have not come from miles away, as 

 has been frequently supposed. 



In all the observations made by the Massachusetts Department of 

 Fisheries and Game on the habits of the scallop records have been kept 

 of the different sets in many scalloping localities in the State, and no 

 case of extended migration has been recorded. It has been impossible 

 to make as extended observations in the deep water as in the shallow, 

 but there is every reason to believe that the same conditions hold true, 

 in spile of the fact that the scallops can more frequently be carried by 

 the current. 



A further fact of interest in this connection is the distinction between 

 the two sizes of scallops, the large channel or deep-water scallop, and 

 the small shallow-water or eel-grass variety. These two are the same 

 species, but, owing to the better growing conditions in the deep water, 

 the channel scallop is much larger in size. If the scallop were a migra- 

 tory form, and would travel first to deep water and then to shallow, 

 there would be no well-marked distinction between these two groups, as 

 all scallops would be approximately the same size. This fact furnishes 

 excellent proof that there is no such thing as definite migration. 



In conclusion, the matter can best be summarized by stating that while 

 the scallop is capable of swimming through the water by its own exer- 

 tions, it can never travel any great distance in this way, and that there 

 is no such thing as definite voluntary migrations. While no exact proof 

 can be obtained there is not sufficient evidence to show that the scallop 

 ever travels, and the weight of the evidence implies that there is never 

 any migration. The only possible traveling of the scallop is caused by 

 forces external to the animal, such as wind, current, storms, etc., and is 

 merely a matter of chance. This cannot be styled in any sense a true 

 migration, and there is little evidence to show that any considerable 

 distance is traveled by this means. 



The non-migratory habit of the scallop is of importance to the scallop 

 planter if in the course of future events cultural methods are ever 

 applied. It is also of great importance to the town, as no town may 

 feel that their scallop crop will travel to the borders of the neighboring 

 township. The scalloping towns can rest assured that, if the scallop 

 crop is once within their borders, there is slight chance that it will 

 ever leave. 



RECOVERY FROM INJURY. 



Scallops are frequently found with twisted and warped shells, or 

 other deformities. Jackson (4) reports finding scallops with portions 

 of the mantle missing, evidently from the attacks of predacious fish. 

 Occasionally small fish about 1 inch in length are found within the 

 scallop shell. In many of the growth experiments, where the scallops 

 were kept in confinement in wire baskets, the growth was abnormal, as 

 the shell grew in a variety of shapes, owing to the manner of resting 



