174 TRANSACTIONS LIVEEPOOL BIOLOGICAL SOCIETY. 



this was a locality where the g^rave pollution of the 

 mussel beds is clue to the direction of the tidal streams. 

 He savs, " The topography of the coast, indeed, renders 

 it impossible that these shell-fish cau escape direct 

 contamination." The actual pathog-enic organism of 

 enteric fever, B. typhosus, was isolated from the mussels 

 examined from this bed. 



In the same year (see our Annual Report for 1906) 

 Mr. Johnstone commenced an extensive investigation of 

 the mussel beds at the " Ring-Hole," and elsewhere in 

 the neighbourhood of Morecambe, a matter of great 

 importance on account of the various interests involved — 

 including the transplantation of ill-nourished, stunte^:l 

 mussels from other localities to this more favoured 

 spot for active growth. The bacteriological results 

 showed that Bacillus coli was present in practically 

 all the mussels examined, but Mr. Johnstone urges 

 that to describe a mussel as dangerously polluted 

 merely because it contains Bacillus coli would be quite 

 unjustifiable. Its presence only indicates the jyossihility 

 that the shell-fish in which it is found may, under certain 

 circumstances, harbour strictly pathogenic organisms such 

 as the typhoid bacillus. AVhen the number of Bacillus 

 coli in a mussel is small, then this possibility is remote. 

 When the number is very large, or when the pollution is 

 notorious (as in such cases as those of the mussels at 

 Egremont, Rock Ferry, or St. Annes), then we may 

 reasonably conclude tliat the shell-fish should not be 

 used for human food. We agree with the Sewage 

 Commissioners when they say, " If it should be seriously 

 contended lliat the mere presence of Bacilhis coli or coli- 

 like microbes in an oyster should condemn it, few oysters 

 woidd probably escape condemnation." The same is no 

 doubt true of mussels. 



