50 REPORT OF COMMISSIONERS OF INLAND FISHERIES. 
tographed were selected as representing the average size on each 
date, together with some of the larger and smaller sizes, placed in 
the bottom and top row, respectively. 
The Rate of Growth Under Specia Conditions —On the sixth of 
July about a pint of clams, taken from the point already referred 

to, were placed in a box of sand in the house-boat, and about one- 
half pit more were added on July 9. The clams were not coy- 
ered with the sand, but were simply scattered over the surface, 
many of them sticking together in clumps. In about five minutes 
they had all burrowed out of sight. The sand box was sunk about 
18 inches below the surface of the water, and, not being affected by 
the rise and fall of the tide, was kept submerged at this depth for 
a month. During the following month, it was occasionally ex- 
posed at low tide when the house-boat was ashore. 
The growth of these specimens was compared from time to time 
with that of the clams in the original locality on the shore, and 
with the somewhat surprising result that the clams at the house- 
boat grew much faster than those on the shore, whence the former 
were originally taken. It is clear, therefore, that it is not neces- 
sary for the rapid growth of the young clams that they be in a lo- 
cality which is exposed at low tide—on the contrary they grow 
faster when they are submerged all the time. This difference in 
the erowth of the clams on the shore and in the house-boat is 
illustrated by.the photographs of samples taken from two locali- 
ties at various times. Compare Fig. 9 with Fig. 14; also Figs. 10 
and 15; Fig. 11 and Fig. 17; Fig. 12 and Fig. 18. 
It might be asked whether the more rapid growth at the house- 
boat was not due to the more favorable position of the latter in 
the tide currents. This may be true in some measure, but yet the 
point of shore in question was washed by a strong current also. 
The house-boat, moreover, was moored within a few rods of the 
point, so that the character of the food is about the same. Some 
other observations confirmed the conclusion that clams grow faster 
od 
when they are continuously submerged. On September 7, on 
another part of the shore, the young clams were examined at vari- 
