SEA-FISHERIES LABORATORY. 91 



There are no certain means of distinguishing between 

 " colon bacilli " of human and lower animal origin, 

 when such are found in shellfish. 

 All mussels are polluted by " sewage bacilli " to some 



degree. 

 There is no standard above which one is justified in 

 regarding the degree of pollution as noxious. 

 In spite of the importance of the subject, the amount of 

 administrative attention it has received and its susceptibility 

 to scientific investigation this is still the case, as it was in 

 1910, when Bulstrode completed his second report. 



So I do not recommend any action, on the part of the 

 Committee, with regard to the mussel beds on the Ribble 

 Channel training walls. The matter has been discussed at 

 some length because it may again become very troublesome 

 and analogous cases may have to be investigated. In such 

 cases as that of Church Scar, where the pollution is gross, 

 immediate, and patent, action may be taken, though, of course, 

 it cannot be taken by the Fisheries Committee. In most 

 other cases, however, the best policy may be for the Committee 

 to oppose any further orders under the Shellfish Regulations 

 should these be initiated in their District, unless the order 

 carries with it an undertaking to provide facilities for cleansing 

 the suspected mussels. If bacteriological evidence is adduced 

 this should be controverted on the ground that there has been 

 abundant time for investigation — which has not been made — 

 and that without this investigation the methods of analysis 

 at present practised are inadequate. A legal decision as to 

 what is to be understood by the expression " attributable " 

 in the Regulations ought to be obtained. 



It has been shown by Professor Klein in 1904, by experi- 

 ments made by this Committee in 1906-12, and by the results 

 obtained at Conway by the Ministry of Agriculture and 



