24 



were carefully counted. They were recounted after three 

 days' incubation, and were found to amount to the average 

 of 700 per T Jo c.c., that is to say, the whole oyster con- 

 tained 70,000 B. typhosus. Exactly the same procedure was 

 followed with oyster 2 dry. The amount of fluid was also 

 just 1 c.c. The average number of typhoid colonies present 

 in the two Drigalski plates (each inoculated with T J ^ c.c.) 

 amounted to 1,200,000 B. typhosus for the whole oyster. Of 

 the subsequent wet oysters the amount of fluid, after mincing, 

 was practically the same, viz., just 1 c.c. Of the dry oysters 

 the amount was less, but it was always brought up to just 

 1 c.c. by adding sterile water. 



Oyster 3, wet 2 days in clean sea water showed 9100 B. typhosus 



per oyster. 



,, 4, dry 2 days dry showed 175,000 B. typhosus per oyster. 

 5, wet 3 days in clean sea water showed 1100 B. typhosus 

 per oyster. 



Seeing from the result in oyster 5 that the number of 

 B. t. is rapidly diminishing, I used for the Drigalski plate of 

 oyster 7 and oyster 9 T T Q c.c. of the oyster, and in the case 

 of oyster 11 I made three plates, each with Y 1 ^ c.c. of the 

 oyster. 



Oyster 6, dry 3 days dry showed 42,000 B. typhosus per oyster. 

 ,, 7, wet 4 days in clean sea water showed 320 B. typhosus 



per oyster. 



,, 8, dry 4 days dry showed 3700 B. typhosus per oyster. 

 9, wet 6 days in clean sea water showed B. typhosus 



in T ^ part of oyster. 



10, dry 6 days dry showed 40,000 B. typhosus per oyster. 

 11, wet 7 days in clean sea water showed B. typhosus 



per T 3 o of oyster. 

 12, dry 7 days dry showed 1220 B. typhosus per oyster. 



All the oysters had their shell well and tightly closed, 

 and on opening were found to be quite normal in appearance, 

 plump and juicy. 



In all the preceding experiments the Drigalski plates 

 contained practically no other colonies except those of 



