84 INLAND FISHERIES. 



MIGRATION TO THE MUD. 



As one would naturally suppose, this period is a critical one for 

 the clam, as mucli so probably as any in its history, though the 

 creature has to contend Avith other great dangers also, which 

 threaten its existence both before and after it enters the mud. 

 The eel-grass on which the Enter onioiy ha filaments grow most 

 abundantly in the localities examined is to be found in shallow 

 water, near the clam beds. In falling from their support, most of 

 the clams would probably find a resting place on the bottom, below 

 the lowest low tide mark. That this actually happens may be 

 easily demonstrated by taking a little of the mud in these localities 

 and washing it through a fine sieve. When this is done the small 

 clams are easily found. It is probably not possible for many of 

 these creatures to reach maturity in this position. I have dug 

 clams below what I should judge was the lowest low tide mark in 

 the salt pond at Wakefield, R. I. On a recent visit to Essex, Mass., 

 I was told by a few of the clam diggers that there were long- 

 necked clams in the bottom of the Essex River, which were always 

 covered by many feet of water. One or two of the diggers believed 

 these clams to be unlike the common long neck in some few 

 details of structure. I was unable to obtain any of the forms for 

 examination, and consequently do not know what this information 

 may be worth. Though it is possible that Mya may, in some 

 instances, be found in bottoms which are never exposed, it seems 

 to me altogether probable that such areas are not numerous. 

 Clam diggers very generally seem to know nothing of their 

 existence. 



I should conclude, then, that of the great numbers of small clams 

 which fall from the seaweed to the bottom below low tide mark, 

 few are able to reach a favorable position higher up on the beach, 

 and the great majority are destroyed. I have seldom found, in 

 such localities, individuals more tlian 6 or 7 millimeters in length. 

 While the majority may thus perish, we may well believe that a 

 few, on falling at certain times, are borne by tidal currents above 



