222 BULLETIN OF THE BUREAU OP FISHERIES 
Table 11. — Number of spat per bushel and per unit of area on shelled bed, Wareham River, Mass. 
Section 
Spat per 
bushel 
Spat in 
each 2 
square 
feet 
Section 
Spat per 
bushel 
Spat in 
each 2 
square 
feet 
A 
7, 632 
12, 640 
17, 648 
20, 624 
16, 736 
1,030 
1,706 
2,382 
2,784 
2,259 
F 
18, 560 
14, 464 
2,506 
1,953 
B 
G 
C 
Average 
15, 472 
2,089 
D 
E 
As has been shown above, the average setting in the crates of the fourth row, 
which was nearest to the bed, was 30,000 over 2 square feet, or about fifteen times 
greater than the average setting over the whole bed. If we compare the setting in 
the fourth row of crates with the setting in the nearest section A of the shelled bed, 
we find that seed production in the crates was nearly thirty times greater than that 
of the adjacent portion of the bed. 
It is apparent from the results of the present experiment that the production of 
seed oysters over a given area of bottom can be greatly increased by the planting of 
shells in crates, thus utilizing three dimensions of the setting zone instead of only two. 
Furthermore, the setting area can be considerably enlarged by planting the crates on 
sand bars or soft mud flats, where ordinary scattering of shells is impossible. If 
necessary, the legs of the crates can be made longer to prevent their sinking into the 
soft bottom. As has been shown by the present experiments, the most intensive 
setting in Wareham River took place about 2 feet above the highest point on the bar 
where shells were planted. It is obvious that many more seed oysters could be 
obtained by planting cultch at this particular level. One would expect that more 
intensive planting might reduce the concentration of spat on shells, but as had 
already been mentioned, a great intensity of setting is not wanted, and for practical 
purposes 3,000 spat per bushel uniformly distributed can be regarded as a fair com- 
mercial set. For the successful growth of oysters, uniformity in distribution is of far 
greater importance than intensity of setting. 
It has been shown that some of the crates were badly damaged by the shipworm 
and other wood-boring organisms and that the crates can be protected by dipping 
them into a solution made of 2 parts of lime and 1 part of cement. In 1928 several 
crates coated with this mixture were planted at the mouth of Crooked River near 
Wareham. They were not attacked by the boring organisms and sustained the 
experiments very well. It is interesting to note that wooden lath coated with a mix- 
ture of lime and cement affords a wonderful surface for the attachment of oysters. 
(Fig. 12.) In one of the crates the number of spat attached to the lath was counted 
by determining the number of spat over 1 square inch at 60 different places taken at 
random on the sides and bottom of the crate. The number of spat varied from 0 to 
50 to a square inch, averaging 14.2. As the outside and inside surfaces of the crate 
have a total area of 1,730 square inches, the estimated number of seed oysters attached 
to this crate was 24,566. In determining the area of the crate, the surface of the 
edges of the lath, which was %-inch thick and was covered with seed oysters, was not 
taken into consideration. The market value of seed oysters which could be easily 
detached from the coated surface of the crate would pay completely for the cost 
of the crate, shell, and labor. 
Experiments carried out in Wareham River proved hat j, the crate method has 
many advantages over ordinary planting, and that it particularly suitable for 
