SEA-FISHERIES LABORATORY. 



77 



of Proteus. It will be seen that in one instance, at least, 

 the organism approached in its reactions the typhoid 

 type. We believe that on account of the presence of this 

 coli group, the identification of the B. typhosus would be 

 difficult in nature. We cannot at present state whether 

 the coli group found in these experiments indicates sewage 

 contamination, or whether, as is quite likely, we are 

 dealing with a group common in the intestine of the 

 oyster and in salt-water. The matter is being investigated 

 by us. But, as bearing upon the next question, we have 

 found that the perfectly fresh oyster contains far fewer 

 bacteria and that the percentage of B. coli is much less. 



IV. — The Infection of the Oyster with the B. typhosus, 

 and its removal by washing. 



The following table shows that the typhoid bacillus 

 does not increase in the body or in the tissues of the 

 oyster. The figures would rather indicate, comparing the 

 large number of bacilli present in the water with those 

 found in the alimentary tract, that the bacilli perish in 

 the intestine. 



Table showing Number of Organisms present in 

 Stomach after infecting Water. 



Oyster 



Inoculated 



Examined 



No. of 



Colonies 



Agar 



Organisms 



present 



in Oyster 



Number present in the 

 Sea-water 



1 



Aug. 25 



Aug. 26 



1,700 



almost en- 



water in the same case 



2 









tirely typhoid 



585,000 per c.c. 



3 



5 J 



Aug. 27 



7,020 



11 



water in the same case 

 468,000 per c.c. 



4 



5 J 



Aug. 28 



7,000 



»> 



water in the same case 

 40,950 on agar, 5,200 

 gelatine per c.c. 



5 



Aug. 26 



Aug. 29 



455 







6 



Aug. 28 



Aug. 30 



195 



>5 



water in the same case 

 2,047,500 per c.c. 



7 



j> 



Sept. 4 



390 







8 



Aug. 31 





325 







9 



5 > 



Sept. 10 



455 



»3 





