144 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
should find B. colt to be an organism (say) growing rapidly 
in bile-salt media, fermenting glucose, lactose and dulcite, 
and producing indole, but failing to ferment cane-sugar, inulin, 
and adonite, and failing to give the Vosges and Proskauer 
reaction. This is the standard adopted in the analyses made 
for the Fisheries Committee. If a less stringent diagnosis 
is adopted, say that of an organism growing rapidly in bile-salt 
media, fermenting glucose and lactose, and giving the indole 
reaction and a neutral-red fluorescence, then the results 
should indicate the contamination as due to “ intestinal,” 
or “ faecal ’’ or some other category of organisms. 
The Necessity for Bacteriological Analyses. 
Even when due stress is laid on epidemiological results, 
bacteriological analyses are necessary : topographical evidence 
can hardly be considered without this adjunct. The investiga- 
tion of suitable and practicable places for relaying, and the 
criteria of the results of relaying, must obviously be obtained 
by analyses. 
