184 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



Sufficient time has not yet elapsed to make a complete 

 bacteriological analysis of the mussels. We have only 

 attempted to demonstrate whether or not the mussel bed 

 was grossly contaminated with sewage matter, and whether 

 the fish had been feeding on the sewage. The stomachs of 

 a dozen fish were examined, as well as the water in the 

 shells. All the stomachs, with the exception of two (which 

 were sterile), contained sewage bacteria in quantity. 



In the examination of the stomach contents, cultures 

 were made on phenolised agar, on Dr. Griinbaum's neutral- 

 red, bile-salt, agar medium, and in milk tubes. The object 

 of the first two cultivations was to isolate bacteria of 

 intestinal origin, and of the latter, to isolate Bacillus 

 enteritidis sporogenes. Hardly any bacteria except those 

 belonging to the ' colon-group ' and the ' typhoid-Gaertner ' 

 groups grow on these media. The presence of colon 

 bacteria in any quantity in water or in an article of food 

 is regarded by most bacteriologists as undoubted evidence 

 of faecal contamination. Bacillus enteritidis sporogenes 

 is a virulent bacterium which is regarded by Dr. Klein as 

 the cause of certain outbreaks of epidemic diarrhoea. The 

 presence of these bacilli together is regarded as certain 

 evidence of sewage pollution. 



Both of these groups of bacteria were found in nearly 

 all of the mussels examined. Colon bacteria were abundant 

 in all the cultures made. Bacillus enteritidis sporogenes 

 was not so abundant, but was present in all the special 

 cultures made to determine its presence, and gave all the 

 characteristic reactions. There is no doubt then, that this 

 mussel bed is grossly contaminated with sewage matter, 

 on which the shell- fish have been feeding, and that, 

 consequently, if used as food these mussels may be, in 

 certain circumstances, the source of grave danger." 



