195 



others wiili the oxceptions of mussels ^) and 7, which were 

 sterile bolh to this microbe and to the microbe usually- 

 identified as B. enteritidis x-porogenes. 



A furtlier analysis by Houston's method of decimal 

 dilutions was also made. Five mussels selected at random 

 from all those collected were pounded up in a sterile 

 mortar with sterile water and three primary cultures were 

 made, both in neutral-red a<^ar and in litmus milk 

 incubated anaerobicalh. The results were: — 



B. coli was therefore present in 1-lOOOth part of a mussel 

 in small numbers, but absent in 1-lOOOOth part of a 

 mussel. B. enteritidis sjxjvoffoies was present in 1-lOOth 

 part of a mussel, but doubtfully present in 1-lOOOth part, 

 and certainly absent in 1-lOOOOth part. 



Conclusions. 



It will be seen, then, that Bacillus coli was isolated 

 from the majority of the mussels examined. The presence 

 of this microbe indicates tlie contamination by faecal 

 matters of the shellfish in whicli it is found. But 

 unhappily this organism must now be regarded as present 



