OF MASSACHUSETTS. 81 



to the importance of the short life of the scallop in regulating the 

 fishery by law. This knowledge is particularly applicable to protective 

 legislation. The length of life permits but one spawning season, when 

 the scallop is one year old. After spawning the average scallop is 

 valueless for the maintenance of the race, and does not need protection. 

 Thus the scallop under one year old, the "seed" scallop, is the only 

 one that should be protected by law. No legislation is necessary for 

 the scallop past its prime. For this reason restrictive legislation, such 

 as limiting the catch by the town law, except when it is to the pecuniary 

 advantage of the scalloper, to avoid " glutting " the market, is unneces- 

 sary, and only works to the detriment of the fisherman, as all scallops 

 not taken will perish before another season. The fisherman should be 

 given freedom in his dredging, provided he observes the all-important 

 "seed" scallop law, as he can catch all the old scallops without in- 

 juring in the slightest degree the future industry. 



The Growth Line. The shell of the scallop is increased by calcified 

 secretions of the mantle, which add fine concentric rings to the growing 

 edge. If one observes the shell closely one will find that it is made up 

 of microscopic growth lines, due to the method of growth. 



On scallops which reach a second summer there is found a growth 

 line, more or less pronounced, which can be likened to the year marks 

 seen in cross-section of tree-trunks, and is given the name of the annual 

 growth line. Growth lines with the oyster are helpful in determining 

 the age, and this line marks the distinction between the adult and 

 " seed " scallop, and has attained considerable prominence as the basis 

 of the " seed " scallop law. 



The annual growth line is formed in Massachusetts waters about 

 May 1, when the scallops resume their growth after the cold winter 

 months, during which all growth has ceased. Necessarily, during the 

 long period of nongrowth, from November to May, the edge of the 

 shell has become thickened or blunted by more or less wear, and when 

 the new growth is secreted by the edge of the mantle on the inner 

 side of the shell a distinct ridge is formed, marking the separation of 

 the old and new growth. The location of the growth line varies between 

 the limits of 10 to 65 millimeters from the hinge, depending upon the 

 size of the scallop when it ceases growing in the fall. We have already 

 shown that there is a similar variation in the size of the " seed " scallop, 

 owing to difference in its situation and the time of spawning. As a rule, 

 the line is 30 to 40 millimeters from the hinge. In some scallops it is 

 very prominent, while in others it is difficult to discern at first glance; 

 sometimes the shell shows a difference in color between the two parts, 

 at other times both the old and new growth are alike, and it is neces- 

 sary to run the finger down the shell to determine the ridge. However, 

 these cases are the exceptions, and the average growth line is especially 

 prominent on the lower or right side of the animal, the upper valve 



