OF MASSACHUSETTS. 89 



from the deep water or channel, while the smaller were taken in the 

 eel grass or shallow water. This difference held true to such an extent 

 that the scallop fishermen could tell by the appearance of the scallop 

 from what section of the bed it came. The shallow-water scallops are 

 much smaller, usually proportionately thicker, and have not the large 

 " eye " and fine appearance of the channel scallops, which are preferred 

 by the scallopers. From a study of the natural conditions of the scallop 

 beds, it appeared that this difference in growth was not due to the mere 

 change in the depth of water but was due to current. The channel 

 scallops on clear bottom receive better circulation of water than in the 

 eel grass, which cuts off nearly all flow of water. Places were found 

 where scallops in deep water without current showed no more growth 

 than the shallow-water variety, while, on the other hand, shallow-water 

 scallops situated near the mouth of an estuary where the tide flowed 

 swiftly back and forth were nearly as large as the deep-water variety. 

 Therefore, while the general distinction between large and small scallops 

 appears to be merely that of deep and shallow water, the fundamental 

 reason is the presence or the lack of current. 



(2) Penned Scallops at Monomoy Point. Two pens were located 

 in the Powder Hole at Monomoy Point in 1906. The first was located in 

 an unfavorable situation in shallow water, in thick eel grass which shut 

 off all circulation. The second pen was located in a more favorable 

 situation, where the eel grass was thin and a gentle circulation was 

 caused twice a day by the inflowing of the tide. This pen was situated 

 close to the shore and was by no means adapted for more than ordinary 

 growth. In comparing the growth of the two pens, from May 1 to 

 August 1 for the same sized scallops it was found that pen 1 gave a 

 gain in volume of 12 per cent., while pen 2 furnished an increase of 35 

 per cent, for the same sized scallops, or nearly three times as fast as 

 pen 1. This furnishes a concrete example of the effect of the lack of 

 circulation, as other conditions were very similar in the two pens, 

 which were situated only a short distance apart, in the same depth of 

 water, and about the same distance from shore. 



(3) Basket Growth on Raft and on Shore. Scallops of the 1906 

 set were obtained from Stage Harbor, Chatham, Sept. 7, 1906, and 

 suspended in wire baskets from the raft (Fig. 79), and in pen 2 near 

 the shore. The scallops on the raft, which was located in the deepest 

 part of the Powder Hole, received the best circulation of water and 

 showed a surprisingly fast growth. The difference is brought out by 

 comparing the raft growth with the natural growth of the Stage Harbor 

 set for the same time, and for the basket growth in pen 2 of the same 

 set of scallops. The gain from September 7 to November 22, a period of 

 seventy-six days, was 17.28 millimeters for the raft, 14.08 millimeters 

 for the Stage Harbor scallops, and 10.40 millimeters for the shore. 

 Considering the raft growth as 100 per cent., Stage Harbor would be 



