172 THE MOLLUSK FISHERIES 



from numerous experimental beds under great variety of conditions. For 

 simplicity, a l-inch clam is taken as the standard. 



A 1-inch clam will grow in one year to a size between 2 and 3 inches. 

 Under fairly favorable conditions, with a moderate current, a 1-inch elam 

 will increase to 2% inches, or a gain of, 900 per cent, in volume. For 

 every quart planted, the yield in one year will be 9 quarts. For beds without 

 current, 1-inch elams average about 2 inches, or a gain of 500 per cent.; 

 i.e., five quarts for every quart planted. Beds under exceptionally fine con- 

 ditions have shown the amazing return of 15 quarts for every quart of 

 1-inch clams planted. Clams increased in these beds from 1 to 3 inches 

 in length. Therefore, by planting clams 1 inch or over, under favorable 

 conditions a marketable clam can be produced in one year. 



What is the maximum production per square foot? 



The number of clams per square foot that can be raised to the best 

 advantage depends upon the location of the flat in respect to natural con- 

 ditions. Clams thickly planted (15 to 20 per square foot) in favorable 

 locations may show a greater growth than when thinly planted (5 per 

 square foot) in less favorable locations; therefore, no definite statement 

 can be made which vrill apply in all cases. The only rule that can be 

 given is that a flat with a current will produce a greater number of clams 

 per square foot than one without a current. On good flats elams can be 

 planted conveniently and economically from 10 to 15 per square foot, or 

 even a larger number. 



What results can be obtained by planting on barren flats? 



There are two groups of flats which come under the term barren: (1) 

 flats which once produced clams in great numbers, but now are practically 

 barren, except for an occasional clam here and there; (2) flats which never 

 have produced clams, and on which for physical reasons clams can never 

 grow. The first group of flats is alone considered in this answer. 



Experimental beds were planted on certain flats in the Essex River which 

 come within the first group of barren flats. These once productive flats 

 had been cleaned out in the past, and for some reason had not seeded 

 naturally. Forty beds were laid out under all kinds of condition?, with 

 the object of finding a way to make these once more productive. Eesults 

 have been all that could be hoped for. Only 4 poor beds were found, out 

 of the 40 laid out; 36 beds were in thriving condition. It should be noted 

 that no attempt was made to choose the best places, but all conditions were 

 tried. Over two-thirds of the clams were re-dug, the increase averaging, 

 in terms of 1-inch clams, over 1,000 per cent., or 10 quarts for every quart 

 planted the year before. 



If many acres of Massachusetts flat, idle at present, are capable of 

 such a yield, should such economic waste be allowed? Why should not 

 the towns, by the expenditure of a little money, restock flats such as these 

 for the benefit of their inhabitants? I do not say that all flats can be made 

 productive in this way, as I know of many cases where the mere sowing 

 of seed clams will not restock a flat; but I do say that Massachusetts pos- 

 sesses enough flats of the former nature, "Which should be made a profit 

 to her clammers. Clam set occurs, as Mr. Stevenson shows in his report, 

 in large quantities; the transportation of seed clams is easy; planting re- 

 quires little labor, the practical way being to sow the clams, which burrow 

 readily; while the yield in proportion to the labor is enormous. 



