SEA-FISHERIES LABORATORY. 455 



the sample from a definite fishing ground, if that fishing 

 ground is to be condemned as the result of the analysis. 

 In the present Report the main evidence considered 

 is that founded on repeated surveys of the shell-fish beds. 

 It might be urged that (as in Dr. Bulstrode's last 

 enquiry) this evidence is, in itself, sufficient. Never- 

 theless, bacteriological analyses have been made, but it 

 must be pointed out that these are only provisional ones, 

 and that the detailed investigation of the bacteriology of 

 the mussels from local sources is still proceeding, and 

 will be reported upon in due course. 



Epidemiological Evidence and Standards of 

 Impurity. 



"We must be under no illusions as to what is meant 

 by " epidemiological evidence." This is a department 

 of public health work into which the layman is rather 

 diffident about entering — perhaps even the epidemiologist 

 fears to tread there. But, after all, the conclusions are 

 only such as require the balancing of very ordinary 

 evidence; and it is not, apparently, a field only explored 

 by the medical officers of health, since one finds that 

 " trained investigators," or inspectors, are responsible 

 for many of the results. 



It is all founded, so far as shell-fish epidemics go, 

 on a very few notable investigations : that made by the 

 late Dr. H. T. Bulstrode, in the cases of the famous 

 enteric explosive outbreaks at the Mayoral banquets at 

 Winchester and Southampton in 1902, for instance; and 

 that made by Dr. Hamer in the case of an enteric 

 outbreak in the East End of London in 1911. It cannot 

 be maintained that either the care with which these 

 outbreaks were investigated, or the success attending 

 the enquiries, have been paralleled in other similar 

 investigations. 



