INLAND FISHERIES. 83 



and tliat these attachments by the minute clam take place in the 

 months of June, July, and Aug-ust — the great majority of them in 

 Narragansett and Buzzards Bays in the latter part of June and 

 in early July. Having become fixed in this way by a byssal 

 thread, the clams remain for some time, many of them attaining a 

 length of at least C or 7 millimeters, and perhaps more. 



FREEING FROM ATTACHMENT. 



It may be Avell to notice, at this point, the fact that the attach- 

 ment of the clams may be broken at any time, apparently at the 

 will of the animal, by a casting off of the b^^ssal thread. This is 

 a very usual phenomenon among lamellibrauchs with a byssus, 

 and may be well observed in the black mussel, MytiluH edulis, 

 where the byssus is very greatly developed. Here, as well as in 

 the young clam, all the threads may be cast off" from the gland in 

 the foot, and new threads may be produced at will. Apparently 

 young clams of all sizes in the Aveed very often perform this 

 function. When they have in this way made themselves free in a 

 glass dish, they at once begin to move about by means of the well 

 developed foot. Slowly crawling about for a time, they finally 

 conclude to reattach themselves, and even after this has been 

 accomplished, they often crawl about in various directions to the 

 length of their tether. In this process of freeing and reattachment, 

 however, it often happens that the little clams fall from the 

 supporting weed altogether, and reach the liottom. In order to 

 determine, if possible, how frequently this happened, I kept a 

 large mat of Eiiteromorplia, covered with clams, floating in run- 

 ning sea water. Under the mass was spread some fine cloth. In 

 the course of a week, great numbers — perhaps a fourth of all those 

 attached— were found to have fallen from their sup]3ort on to the 

 cloth, and these were of all sizes. Here they attach themselves, 

 wander about, and again attach, until, apparently tired of the 

 efibrt to find congenial surroundings, they remain inert, most of 

 them without byssal threads, for long ]ieriods of time. 



