550 U. S. BUREAU OF FISHERIES 
servations failed to support either view, as the salinity of the water 
was rather low and no conchs were found on the reefs. 
Preliminary observations tend to show that the planting of shells 
on suitable bottoms will probably increase the production of oysters 
to such an extent that Mississippi consumers will be independent of 
Louisiana. 
North Carolina—A survey of Core and Pamlico Sounds has been 
undertaken in cooperation with the State fisheries commission, Mr. 
Seiwell, temporary investigator of the bureau, conducting the field 
work. Since 1920 over $300,000 has been spent by the State in 
planting oyster shells in these waters. It was the purpose of this 
investigation to ascertain the results of the planting operations; 
to determine the value of various sections of the sound as seed-pro- 
ducing and oyster-growing grounds; and to acquire fundamental 
knowledge regarding the physical, chemical, and biological condi- 
tions existing in these waters and controlling the growth and propa- 
gation of the oyster. Observations extending over a period of two 
months (November and December) indicate that in Pamlico and 
Core Sounds the currents, and consequently the distribution of the 
salinity, depend almost entirely upon the winds; that the fluctua- 
tions in the temperature of the surface water can be correlated 
directly with a rising or falling air temperature; that bottom tem- 
peratures are usually 2° to 8° C. lower than that of the surface; 
that the oxygen content of water varies from 1,000 milligrams per 
liter to 8.85, and free CO, varies from 2.2 to 6.8 milligrams per liter. 
Numerous determinations of Ca content in water were made, and 
many bottom and plankton samples were collected and analyzed. 
The work will be carried on throughout the year, and special atten- 
tion will be directed to the study of spawning of oysters and 
abundance and distribution of set. 
SPAWNING OF THE OYSTER 
In the summer of 1926, experiments were conducted by Dr. P. S. 
Galtsoff at Woods Hole, Mass., on the spawning reactions of the 
oyster, which were studied under laboratory conditions. Both male 
and female oysters can be induced to spawn by raising the tempera- 
ture of the water. However, at a constant temperature the female 
can be forced to spawn by adding sperm to the water. The details 
of this experiment are given at greater length on p. 653 of this report. 
The following practical applications of the experiments can be 
made: 1. In certain localities the female oysters can be induced to 
spawn by adding sperm to the water. 
2. For successful spawning, the oysters should be planted on the 
spawning grounds as densely as possible. 
BEHAVIOR OF THE OYSTER LARVA AND CONDITIONS CONTROLLING SETTING 
IN NORTHERN WATERS 
In addition to the practical experiments, studies were made in 
Milford Harbor by H. F. Prytherch in 1926 dealing primarily with 
the larval and subsequent attachment periods, both of which are of 
great importance from a scientific as well as practical standpoint. 
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