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BULLETIN OF THE BUREAU OF 'FISHERIES 
period of treatment 15.82 hours per day open, and specimen No. 2 averaged only 8.11 
hours per day open. At the same time, however, the controls (fig. 22) did not remain 
open as long as expected. While specimen No. 3 averaged 17.42, specimen No. 4 
averaged 18.22 hours per day open, during the period in which the experimental 
specimens were in liquor solution. Both controls, however, gave a higher average 
than either of the experimental 
oysters. The reason for the con- 
fusion appears in Figure 24, in 
which daily temperatures are pre- 
sented. The curves of all speci- 
mens in both experiments show 
almost perfect parallel to the tem- 
perature fluctuations. They were 
open more at high than at low tem- 
peratures. The effect of temper- 
ature on shell movements is dis- 
cussed more fully in another pub- 
lication. (Hopkins, 1931.) This 
explains the low records of the con- 
trols, but it does not explain the 
distinctly lower records made by 
the experimental oysters, which show that the presence of the liquor caused an addi- 
tional effect. All specimens were living when the test was ended. 
Experiment No. 8 ( 0.44 parts per thousand). — In this case water flowed at the 
rate of 368 cubic centimeters per minute and liquor (1 : 9) at 1.6 cubic centimeters per 
minute. The two specimens (fig. 23) gave inconclusive results during the short 
experimental period. Specimen 
No. 5 averaged 19.21 and specimen 
6, 13.0 hours per day open. These 
figures are not different enough 
from the controls to be significant. 
For such a low concentration a 
longer period of treatment appears 
to be necessary. 
Experiments Nos. 2 and 3 
(October 20 to November 22, 1 929 ) . — 
These tests were carried on in un- 
heated water of pH, seldom vary- 
ing from 7.8. The temperature of 
the water was between 12° and 13° 
C. at the beginning but by the time 
the experiments were stopped had fallen to around 5° C. The stock liquor solution 
was made up of 1 part pure liquor to 19 parts sea water. 
Experiment No. 2 (0.52 parts per thousand).— Water entered the mixing chamber 
at the rate of 84 cubic centimeters per minute and liquor (1 : 19) at 0.88 cubic centi- 
meters per minute. The pH of the mixture was 7.2 to 7.6 in the experiment chamber. 
Effect of the liquor is clearly. shown in the graphs (fig. 25) of these two specimens 
as compared with those of the two controls (fig. 26). After the liquor was introduced 
DECEMBER JAN. 
Figure 22. — Graph giving records of the control oysters in experiments 
Nos. 8 and 9 (figs. 21 and 23). The variability in height of records is 
parallel to fluctuations in water temperature (fig. 24) 
DECEMBER JAN. 
Figure 21— Graph showing records of the two specimens in experiment 
No. 9 (0.7 part per 1,000). Kymograph sheet covering records for 
three days were lost. Compare with controls (fig. 22) and with the 
record of daily temperature, the fluctuations of which caused much 
of the variability in the behavior of the specimens 
