_Rate of Growth of the Clam._--The report of the Commission on Fisheries and Game for the year 1906 contains the following statements:-- _What is the natural growth of the clam per year?_ There is great diversity in the growth of the clam, owing to the location in respect to three essential conditions,--current, length of time submerged, and soil. The following figures give briefly the general trend of results from numerous experimental beds under great variety of conditions. For simplicity, a 1-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 clam will increase to 2½ 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 clams average about 2 inches, or a gain of 500 per cent.; _i.e._, five quarts for every quart planted. Beds under exceptionally fine conditions 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 conditions. 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 will 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 clams 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.