SEA-FISHERIES LABORATORY. 173 



than those, probably, of any other part of the coast. I 

 shall only refer now to a few of Mr. Johnstone's investi- 

 gations as examples : — 



In 1904, Mr. Johnstone reported on the mussel beds in 

 the Mersey Estuary and in the Estuary of the Lune, and 

 on the deep-sea oysters of onr district. In this paper the 

 dangerous pollution of the Egremont mussels was clearly 

 demonstrated, amounting in some cases to about 300 

 colon bacilli in a drop — say one-tenth of a cubic centi- 

 meter — of the stomach contents of the shell-fish. The 

 Rock Ferry mussel bed was also shown to be grossly 

 polluted in some parts. The Wallasey bed, although 

 yielding some evidence of sewage^ was clearly much less 

 polluted than in the case of the Egremont and Rock Ferry 

 mussels. 



The examination of the Lune Estuary was made at the 

 request of the County Council ; and Professor Delepine, 

 of Manchester, also made an independent investigation 

 and report. The results showed the presence of sewage 

 organisms, but that compared with the Egremont mussels 

 the pollution of the Lune mussel beds is not excessive. 

 Finally, " deep-sea " oysters from various off-shore fishing 

 grounds were found to be unpolluted. 



In this paper Mr. Johnstone doubts the practi- 

 cability of erecting a permissible standard of impurit}^. 

 The deep-sea oysters would satisfy any standard, the 

 Egremont beds would be condemned on any adequate 

 standard, but the Wallasey beds are in an intermediate 

 condition, and there might be difference of opinion 

 amongst experts as to whether the standard should pass 

 or condemn that degree of pollution. 



In the Summer of 1906, Mr. Johnstone furnished a 

 report to our Scientific Sub-Committee on the state of 

 a flairs at St. Annes-on-the-Sea, in which lie showed that 



