46 



OYSTERS AND DISEASE. 



In the next series of experiments infected oysters were taken, the duplicates of 

 which, as seen in the above table, contained comparatively large numbers of the B. typhosus. 

 They were subjected to a running stream of pure clean sea-water. The result was definite 

 and uniform ; there was a great diminution or total disappearance of the B. typhosus in 

 from one to seven days. 



IV. — The Bacteria present in the Alimentary Canal of the Oyster and 



THE Mussel and other Shellfish. 



The method of analysis consisted in first cauterizing the mantle over the region of 

 the stomach and then inserting a fine sterilized glass pipette ; the pipette was moved 

 about, and when sufficient of the contents of the stomach and the juices of the oyster 

 had risen in the pipette, the latter was removed and its contents transferred to liquefied 

 agar, ordinary gelatine, or sea-water gelatine, and plate cultivations made. In the first 

 six cases examined (see Table, A — F) the oysters were especially fresh ; in all the other 

 cases the shellfish had been obtained hap-hazard from the various shops. In a very 

 large proportion of cases (^ to ^) the B. coli was isolated. In very many instances 

 this organism was present in overwhelming numbers in the Petri dish. 



