88 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



the consumption of shellfish, within the district is likely to cause 

 danger to public health, he shall take such steps, etc." The 

 steps are the holding of a local enquiry at which the fishermen 

 are called upon to show cause why the shellfish beds suspected 

 should not be closed to ordinary fishing. This procedure, which 

 apparently bears rather hardly on the fishermen, does not do 

 so in reality, for its result must usually be to put the local 

 fishery administration on their side : the latter does not appear 

 to have any definite locus standi in the matter in the course 

 of the enquiry. Here, too, it is quite relevant to ask for the 

 definite results of such enquiries and closures that have taken 

 place, for the making of an order closing a certain mussel bed 

 is not at all the same thing as the prevention of taking mussels 

 from that bed. Have the " Shellfish Eegulations " really 

 prevented the marketing of polluted mussels ? We are 

 enquiring into the causes of the decrease in enteric fever during 

 recent years and so the question is a relevant one. 



The important thing in the " Shellfish Regulations " is the 

 phrase attributable to shellfish. What evidence satisfies the 

 Medical Officer of Health that any particular case of typhoid 

 fever has been caused by eating, say, mussels. Study of the 

 cases quoted above will show, I think, that there is no satis- 

 factory legal evidence at all. A man takes the disease, and the 

 investigators discover that he has, during the two weeks 

 previously, eaten shellfish, bought at a particular shop or stall 

 or barrow in the streets. There is no possibility of proving 

 that these particular shellfish were competent to cause infection, 

 because it is only sometime after they have disappeared that 

 their association with a case of disease was suspected. Enquiry, 

 however, shows that shellfish of the same origin are still being 

 sold, and these are analysed and are found to contain evidence of 

 sewage pollution. Thus the outbreak of disease is " attributed " 

 to them. Now the association thus set up is so loose and 

 unsatisfactory that we are impelled also to consider the fact 



