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BULLETIN OF THE BtTBEAU OP FISHERIES 



, The majority of the oysters began to produce a current at a temperature between 

 8.1° and 9°, though in a few of them the beginning of the flow of water took place 

 either below or above this temperature interval. No current was observed at 5° 

 and below. This result confirms what has been observed in the summer experiments 

 (see right column of the table) and shows that so far as the activity of the ciliated 



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r 2° 3° 4° 5° 6° 7° 8° 9° 10" II 



TEMPERATURE' C 



Fig. 7.— Frequency distribution of the beginning of current at diflerent temperatures 



epithelium of the gills is concerned there is no special adaptation to low temperatures; 

 in hibernating oysters the current produced by the gills begins and ceases to flow 

 at the same temperatures as in the summer oysters that were chilled suddenly. 

 Examining Figure 7 one notices that in summer oysters the peak of the frequency 

 curve is not so pronounced as it is in winter experiments, but this slight difference is 

 insignificant and should be attributed to the greater number of winter observations. 



