92 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



In any particular case what is now the object of inspection 

 and analysis ought to be the establishment and satisfactory 

 working of purification plant, and not the official condemnation 

 or approval of any particular shell-fish laying. And this is 

 really implied in the Shell-fish Regulations. But there is no 

 other method of testing the degree of success of working of a 

 shell-fish purification plant except by bacteriological analysis. 

 What is indicated, or rather what is aimed at, is a considerable 

 reduction of sewage organisms as the result of the process 

 of purification. 



The " Bacillus coli " question. 



As an academic question there can be little doubt as to 

 whether or not any specific sewage organism is or is not that 

 known as Bacillus coli communis. But the process of identifi- 

 cation is laborious, and generally inapplicable in the actual 

 conditions of routine public health work applied to shell-fish. 



In spite of the apparently exhaustive report of the Royal 

 Commission on Sewage Disposal, the question as to what ought 

 to be understood by " B. coli " or " coli-like organisms " was left 

 obscure. The large amount of evidence heard by the Commission 

 was out of all proportion to the scanty measure of scientific 

 investigation on which this evidence was based, or which 

 was actually undertaken by the Commission. Therefore there 

 is still conflict of opinion both as to the diagnostic characters 

 of the organisms indicative of dangerous sewage pollution, 

 and as to the standards of impurity — that is, in the routine 

 methods of public health laboratories. There is still no sign 

 that this conflict of opinion is likely soon to be resolved. 



The nature of the polluting organisms. 



For some time back all sewage organisms isolated from 

 mussels and polluted sea-water have been studied in detail 

 in our laboratory. A provisional report on these results was 

 made in the Annual Report for 1914. Not many organisms 



