REPORT OF COMMISSIONERS OF INLAND FISHERIES. 31 
ous levels, from below mean low-water mark to half tide, and the 
larger growth of the former was noticeable. This is illustrated 
by samples which were taken at very low tide, and at about half- 
tide (Figs. 21 and 22). 
The following experiment, made to ascertain the rate of growth 
of individual clams transplanted to another locality on the shore, 
shows, also, that the growth is greater near the low-water, mark. 
On the 22d of July a number of young clams of average size, taken 
from the point on Cornelius Island, were carefully measured, and 
planted in the land tiles. The tiles were set perpendicularly into 
the ground, and filled with sand taken from above tide mark, in order 
that no clams might be accidentally put into them, and were ar- 
ranged in a row, from extreme low-water mark to high-water mark, 
at intervals of about two feet. Each clam was carefully measured 
and placed in a tile by itself (in some cases two specimens were 
put into the same tile). On September 18 some of these were 
taken out and measured again, the rest being left undisturbed. 
The measurements are of the long diameter of the shell, and are 
given in millimeters. The accompanying diagram shows the rela- 
tive position of the tiles which contained the specimens measured 
on September 18. No.1 is at extreme low tide, and No. 8 some 
what below half-tide mark. 
Number, July 22. September 18. Growth in 2 Months. 
(Seats! esis tay 13mm 28mm 15mm 
(Wis fc ore cne 3 Dea 36. 24 
(CO) Fes Bees AMA ae 40 * 2 One 
(Gye 
BRR FE ee ila a Soa 
(3 Vemerererecsts Slides 46 “ 33 “ 
(Dan Gt cee ies 5 ASS 33 “ 
Gb) meameree 13 ~*~ gone. 
Reference to this table shows at once that the clams grow 
more slowly as we go up the shore from low-water mark. Com- 
pare for example Nos. 3 and 8, which at the time of planting were 
