132 
BULLETIN OF THE BUREAU OF FISHERIES 
Changing a paper occupied only 15 minutes, during which time the loss of records is 
insignificant. After fixing a completed paper in shellac it was marked off into hourly 
and daily periods and the records analyzed. 
During most of the experiments thermograph records were kept of the tempera- 
ture of the water in which the specimens were immersed. The bulb was inserted into 
the middle chamber with the control specimens, for the metal might be attacked by 
the liquor in the other chambers and so introduce a source of error. In the three 
experimental compartments the 
temperature was so nearly the same 
that the maximum difference ob- 
served was hardly over 0.2° C. 
In the winter weather, when 
the pumped water was around 5° 
C. or lower, the water was heated 
slightly before entering the large 
aquarium jar. It passed through 
a lead coil which was immersed in 
a pail of water under which a ker- 
osene flame burned. The result- 
ant water in the experimental 
chambers was usually of about 15° 
to 17° C., or high enough to per- 
mit the oysters to feed and grow. 
A fresh supply of sea water 
was maintained by means of an 
automatic pump, which pumped 
water at intervals of one to two 
hours into two 50-gallon oakbarrels. 
The laboratory (fig. 5) was in a 
cove which formed a part of Oyster 
Bay, but which at low tide was 
well above the level of bay water. 
Figure 4.— Diagram showing the arrangement of connected aquaria, con- q^e COVe Was diked to retain a 
taining experimental (end chambers) and control (middle chamber) spec- 
imens connected to levers which recorded shell movements on the depth 01 2 to 4 ieet 01 Water at 
kymograph. Complete description in text l ow tide. At high tide the bay 
water entered the cove, so that the cove water did not markedly differ from the bay 
water in salinity. 
The supply of liquor and sea water mixture in the 5-gallon carboy was replen- 
ished whenever necessary. This amount lasted for from one to three days, depending 
upon the rate of flow. 
Most of the experiments were carried on without first neutralizing the liquor. 
The pH of the resultant solution was consequently lower than that of the sea water. 
That the effects observed were not due to acidity was shown by a control series. 
GENERAL CONSIDERATIONS 
In Oakland Bay four chief abnormal characteristics of the oysters have been 
observed since spring, 1927. In the first place practically no setting occurred, And 
consequently no seed oysters were obtained. In addition, many oysters died on 
