25 



B. typhosus, and these, after 48 hours and 72 hours, could 

 readily be identified as such. It should also be added that 

 the counting of the colonies, except in the case of dry 

 oyster 2, presented no difficulties, and was always repeated 

 to control the first counting. As was mentioned already, in 

 all instances an accurately measured quantity of the turbid 

 fluid part of the minced oyster, T Jo or -^ c.c. as the case 

 required, was used for Drigalski plates, and the total quantity 

 of the minced oyster was kept at just 1 c.c. Where originally 

 deficient, it was brought up to 1 c.c. by the addition of 

 sterile sea water. 



In all plates the colonies were found isolated, not in fused 

 groups, thus proving that the bacilli were fairly uniformly dis- 

 tributed in the fluid of the minced oyster, and had not formed 

 nests, as it were, in the oyster tissues ; that is to say, had not 

 multiplied and made aggregations within the tissues of the oyster. 

 As was mentioned on a former page, colonies were taken 

 at random, and the required tests examination in the 

 hanging drop, agglutination test, subculture on gelatine, 

 agglutination of this, and ultimately, if required, in other 

 media were carried out. After a little practice the recog- 

 nition of the typhoid colonies on Drigalski plates in all 

 these and the subsequent experiments was merely a matter 

 of patient examination under a magnifying glass. 



Tabulating the results of the preceding Experiment I. we 

 obtain this : 



TABLE I. 



Oysters injected with 160 millions B. typhosus each : 

 WET i.e., kept in clean sea water frequently changed. 



Oyster 1 after 1 day in water, 70,000 B. typhosus per oyster. 

 3 2 days 9100 



5 3 1100 



7 4 320 



9 6 per T X F part 



of oyster. 

 11 7 per -f$ part 



of oyster. 



