560 REPORT— 1898. 



Results. — Oysters. — In nine out of the nineteen batches a colon-like 

 organism was isolated from the interior of the oysters. In some instances 

 there was almost a pure culture of the Colon bacillus, the Petri dishes 

 giving a very characteristic odour. The reaction in the nine cases differed ; 

 there was the typical colon group, coagulating milk, forming indol and 

 gas, and giving a decided acid reaction, as well as an abundant growth 

 upon potato. There was also a group consisting of very active bacilli, not 

 coagulating milk, not forming indol, occasionally forming gas, and in two 

 cases giving rise to a slightly acid reaction in neutral litmus whey, and in 

 three cases to an alkaline reaction. In each suspicious case the serum 

 reaction was carefully tried, but always with negative results. We con- 

 clude that this latter group, although giving some of the reactions of the 

 typhoid bacillus, cannot be regarded as identical with the true bacillus of 

 Eberth. 



Mussels. — The colon group is less frequent ; some of the bacilli isolated 

 coagulated milk, formed gas and indol, whilst others gave negative 

 reactions, as in tlie case of the oysters. 



Cockles. — A colon bacillus was not isolated. A coccus not liquefying 

 gelatine, growing at a temperature of 37° C, and sometimes forming gas, 

 was frequently met with. 



Periwinkles.- — As in the case of the previous group, a coccus was 

 isolated. 



Whelks. — From these a bacillus was obtained, which formed gas at 

 37° C, did not coagulate milk nor produce indol, and only after four days 

 produced a slight acid reaction in neutral litmus whey ; it therefore 

 resembled the second group found in the oyster. 



These observations show the frequent occurrence of the Colon group of 

 bacilli in such shellfish as we have investigated. Moreover, they clearly 

 indicate that some of the organisms composing this group are more closely 

 related in their reactions to the Bacillus typhosus than others are, although 

 none corresponded to that bacillus in all respects. It will be remembered 

 that in our Liverpool Report (1896) we described the occurrence of the 

 typhoid organism after various intervals of time in oysters which we had 

 experimentally infected with typhoid material. To that report ^ we may 

 refer also for a discussion of the results of washing infected oysters in a 

 running stream of sea-water, and for a statement of the diminution of the 

 number of typhoid organisms as the time of inoculation recedes. In our 

 Ipswich paper ^ we had shown that oysters were able to live, and did live, 

 under very impure conditions, and were able to make use of sewage 

 matter as food. We also demonstrated (in 1895) by experiments that 

 those laid down in the proximity of drains contained far more micro- 

 organisms than such as were some distance off in purer water. Finally, 

 in last year's report at Toronto,^ we gave an account of the unhealthy' 

 condition of certain green oysters, of the association of the colour with a 

 leucocytosis, and of the presence of copper in the leucocytes.* 



As the result of these various lines of investigation, and of the exami- 

 nation of oysters alive under both natural and artificial conditions on 



' Brit. Assoc. Rep., Liverpool Meeting, 189P, p. 663. 

 = Ihid., Ipswich Meeting, 1895, p. 723. 

 » Ibid., Toronto Meeting, 1897, p. 363. 

 * See also Proc. Jtoy. Soc, vol. Ixii. p. 30. 



