SEA-FISHERIES LABORATORY". 



3&) 



others with the exceptions of mussels 3 and 7, which were 

 sterile both to this microbe and to the microbe usually 

 identified as B. enteritidis sporogenes. 



A further 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 agar and in litmus milk 

 incubated anaerobically. The results were : — 







No. of 









" Colon- 



Enteritidis 







like " 



reaction. 







Colonies. 





A: 



in 1 cc. (= xnn^ 1 P ar ^ °f a mussel) 



26 



+ 

 Milk de- 



B: 



in 1 cc. (= T Jtjo th 



• 4 



colorised 

 but not 

 clotted. 



C: 



in 1 cc. ( = T ^oo th 



1 



No 

 reaction. 



B. coli was therefore present in l-1000th part of a mussel 

 in small numbers, but absent in l-10000th part of a 

 mussel. B. enteritidis sporogenes was present in l-100th 

 part of a mussel, but doubtfully present in l-1000th part, 

 and certainly absent in l-10000th 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 the contamination by faecal 

 matters of the shellfish in which it is found. But 

 unhappily this organism must now be regarded as present 



