OF MASSACHUSETTS. 25 



is colder than south of the Cape, and the spawning would naturally be 

 somewhat later. In the harbors, such as Wellfleet Bay, the reverse is 

 true, as the broad exposure of flats, heated by the sun, gives a greater 

 warmth to the water. In these cases many scallops are left in little 

 tide pools, where they bask in the sun and shoot spawn in these small 

 natural aquaria. The eggs have thus a chance to develop in quietude 

 until the incoming of the tide, when the little embryos join company 

 with the young from the other pools and begin the keen competition of 

 life. The spawning season lasts from June 25 to August 15. 



(2) On the south side of Cape Cod is found a great variety of terri- 

 tory and conditions, which nearly approximate those of Monomoy 

 Point. The limits of the season in this locality are from June 15 to 

 August 15. 



(3) The conditions at Nantucket and Edgartown closely approximate 

 those on the south side of Cape Cod, and except for local variations the 

 spawning season is the same. 



(4) In the warmer waters of Buzzard's Bay spawning is somewhat 

 earlier, the set usually being about two weeks in advance of Monomoy. 

 The limits of the season scarcely differ from the south side of Cape Cod 

 and the Islands, but the main part of the spawning takes place earlier. 

 The season lasts from June 1 to August 1. The Buzzard's Bay scallop 

 is larger in size than the scallop in the other localities, owing to earlier 

 spawning and rapid growth. 



Fecundation. Fecundation is the union of the female cell (egg) 

 with the male cell (spermatozoon), which results in the formation of a 

 new individual that partakes of the nature of both parents. Since the 

 eggs of the scallop are fertilized externally, in the water, it is com- 

 paratively easy to watch the act of fertilization and the subsequent 

 development of the embryos. In the water a transparent substance 

 envelops the egg, which holds the spermatozoa a short distance from 

 the cell proper (Fig. 6). The only reason for believing that such a 

 substance is present is the fact that preserved eggs still retain the 

 circle of spermatozoa. The attraction of the male cell to the egg is 

 believed by scientists to be of chemical origin. Although the egg is 

 thickly surrounded with spermatozoa, only one is needed for fertiliza- 

 tion, and after its entrance the rest are held outside by the formation 

 of a membrane through which they cannot penetrate. Occasionally 

 more than one spermatozoon enters the egg, but in this case the egg 

 possibly fails to attain complete development. 



(a) Natural Fecundation. Judging from the enormous number of 

 eggs and spermatozoa annually liberated by a single adult scallop, 

 nature seems prodigal with her bounties; but on second thought it 

 appears that an equilibrium has been established and that an abundance 

 of spawn is needed to compensate for the destructive agencies which 

 beset the scallop. It seems strange, perhaps, that the spermatozoa 



