236 REPORT OF THE COMMISSIONER OF FISHERIES. 
The waters of Mount Hope Bay, at least in the areas occupied by 
oyster ground, are also free from sewage pollution of any extent. 
The Warren River, however, from the town of Warren to its union 
with the Providence River, must be considered a polluted stream. 
Examination of oysters and other shellfish from various portions 
of the river and bay show that there is a distinct relation between the 
presence of 2. coli in the water and in the shellfish living in these 
waters. When B. co// is entirely absent from the water it can not be 
found in the shellfish, but when the surrounding waters are infected 
with it it is almost certain to be found in the shellfish. It seems 
probable, however, that 2. co// may be present in larger numbers in 
the water than in oysters, for almost without exception a much larger 
number of water samples than oysters from a given locality gave posi- 
tive reactions for sewage bacteria. This fact may be explained as due 
partly to the influence of the tide currents and partly to the resist- 
ance against infection exerted by the oyster itself. 
Examination of the shellfish from the lower river and bay demon- 
strate that the bacteria usually occurring in oysters taken from uncon- 
taminated waters are such forms as are commonly found in water. 
No organisms of the colon group were isolated from these oysters. 
Hence, analysis of the juice contained within the shells of oysters, 
clams, and mussels is practically an analysis of the water in which 
these molluses are living. The stomachs of oysters are often found 
sterile. £2. col7 has been found in the juice of oysters whose intes- 
tines were apparently free from infection. 
No organism which will grow in the presence of 9.05 per cent of 
phenol has been found in oysters from an unpolluted source. 
The results obtained in these experiments indicate that 2. col7 is 
not normally found in sea water or in the common edible shellfish, 
and that the presence of this organism in oysters, clams, mussels, and 
similar shellfish is an indication of sewage pollution. 
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Conn, H. W. Oyster Epidemic of Typhoid Fever at Wesleyan University. Med- 
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