220 
BULLETIN OF THE BUREAU OF FISHERIES 
We begin our discussion with the crates planted in front of Hamilton and Swifts 
Beaches. Thirteen crates were planted at each locality between the tidal marks. 
All the crates were partially exposed at low water and were set about 10 feet apart. 
A number of them were destroyed during the summer; only 6 crates remaining at 
Hamilton Beach and 9 at Swifts Beach. The wood of the crates was badly damaged 
by the shipworm and hardly was able to sustain the weight of the shells. The differ- 
ence in the average number of spat per crate obtained in each locality was insignificant, 
38,383 at Hamilton Beach and 27,557 at Swifts Beach; the variations in the number of 
spat in different crates (Table 8) were, however, very large. 
Table 8. — Number of spat caught in the crates 
Crate number 
Spat per 
crate 
Crate number 
Spat per 
crate 
HAMILTON BEACH 
25 
94. 000 
56, 800 
10. 000 
2,200 
3,800 
65, 000 
SWIFTS BEACH 
31 
20. 700 
28. 300 
30. 800 
25, 300 
11. 700 
11. 500 
21. 800 
87. 500 
10. 500 
26. 
32 
27 
33 
28 
34 
29 
35 
30 
36 _ 
Total 
37 
230, 000 
38, 383 
38 
39 
Total 
248, 100 
27, 567 
Average per crate 
The low figures in crates 27, 28, 29, 35, 36, and 39 were due to the fact that a 
considerable number of shells were washed out from these crates and the remainder 
represented what, at the time of setting, constituted the central portion of the crate. 
The crates planted at Station II were less attacked by the shipworms, and 
none of them was lost during the season. They were filled with oyster shells, which, 
owing to the action of the waves, became by the end of the season more tightly packed, 
but none of which was either washed out or ground up, as happened with the scallop 
shells. On August 31 a representative sample of shells was taken from each crate 
and the number of spat was counted. The results of counting are given in Table 9. 
The highest average intensity of setting, amounting to 30,117 spat per crate, 
was found in row 4, which was entirely exposed at low water; the lowest setting, 
averaging 5,580 per crate, took place in row 1, which was at all times submerged; 
while in rows 2 and 3 the setting averaged 16,366 and 13,350 per crate respectively. 
Counting the averages for every group of four crates in the lines A to E, we find no 
significant variations in the number of spat. This shows very conclusively that the 
zone of the most intensive setting was above the low-water mark. The maximum 
number of spat (50,100) was found in the crate set on the top of the bar above all 
other crates. (Fig. 13.) 
Table 9. — Spat caught in the crates planted at Station III , Wareham River. {See jig. IS.) 
Row No. 
Line A 
Line B 
Line C 
Line D 
Line E 
Line F 
Average— 
Per crate 
Per bushel 
1 
14. 100 
21,800 
16. 100 
16, 700 
2, 300 
8,200 
9,100 
48, 500 
5, 200 
6,000 
17, 400 
18, 000 
1,900 
20, 100 
6, 300 
47, 100 
3, 900 
15, 700 
15, 700 
24, 000 
5, 580 
16, 366 
13,350 
30, 117 
2,790 
8, 183 
6,675 
15, 058 
2 
26,800 
15, 500 
26, 400 
3 
4 
17, 175 
17,025 
11,850 
18,850 
14, 825 
22,900 
