178 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



important piece of shell-fish work we have undertaken 

 in connection with public health, it was as far back as 

 the summer of 1906 that Mr. Johnstone, in consequence 

 of information we had received as to the condition of shell- 

 fish sent to the markets, commenced . the investigation 

 of the mussel beds in the Estuary of the Conway, in 

 North Wales, an investigation which has been carried 

 on intermittently until the present time, and is probably 

 not yet finished. The Conway mussel industry is of 

 considerable importance. Amounts of up to 6,000 cwt. 

 per month (of the value of over £700) were sent from 

 Conway during part of 1906, to Manchester, Leeds, 

 Huddersfield, Halifax, Nottingham, and other inland 

 towns. 



Sewage, however, is discharged into the Estuary at 

 Conway, and also into the river above, and there 

 can be no doubt that a considerable degree of 

 pollution of the mussels is present. Several out- 

 breaks of enteric fever in inland towns have 

 now been attributed, by Public Health Officers, 

 to Conway mussels. Public enquiries have been held, and 

 a great deal of further work, both topographical and 

 bacteriological, has been done by Mr. Johnstone since 

 his preliminary paper in our Report for 1906. Moreover, 

 an examination of the beds was made along with Dr. 

 Bulstrode in 190T, and along with an Inspector from the 

 Fishmongers' Company in 1908, and our results were 

 entirely confirmed by these independent authorities. But 

 although the Conway mussels are undoubtedly polluted 

 with sewage, still it must be remembered that, in all such 

 cases, it is an unscientific and inconclusive statement to 

 attribute enteric fever in (say) Manchester to the mussels 

 of (say) the Conway Estuary, merely because such mussels 

 when eaten by the patient, or when purchased in the 



