BACTERIOLOGY OF THE OYSTER. 

 Date, November 21, 1913. 



77 



Average Temperature 10.5°C. 



Quantity of 

 Shell Liquor 

 AND Salt Solu- 

 tion. 



No. of Oyster. 



10 



Ic.c 



1-lOc.c 



1-lOOc.c 



+ 

 

 



Score, 19. 



Date, November 24, 1913. 



Quantity of 

 Shell Liquor 

 AND Salt Solu- 

 tion. 



Average Temperature 10.5°C. 



No. of Oyster. 



Ic.c 



1-lOc.c 



1-lOOc.c 



10 



+ 





 



Score, 28. 



-|- = positive presumptive test for B. coli. 

 0=: negative presumptive test for B. coli. 



It is seen from the tallies that the oysters cleaned themselves as 

 much in six days as at any time. The samples taken on the day of 

 transporting showed on the average twenty-three B. coli per cubic 

 centimeter of oyster juice. Six days later the sample showed only one 

 B. coli per cubic centimeter and they showed no further cleansing 

 after ten more days. The fact that the water at this place is not 

 entirely free from sewage contamination probably explains why the 

 oysters did not show any further elimination of B. coli, apparently 

 there were enough B. coli in the water to maintain a small number in 

 the oyster at all times. 



Condasions. 



In one experiment with a temperature averaging 9.7''C. over the 

 period of the investigation the oysters showed an elimination of B. 



