218 REPORT OF THE COMMISSIONER OF FISHERIES. 
The section of the river 2 to 4 miles below the chief source of con- 
tamination is much freer from pollution. 6. colz was found in 59 per 
cent-of the samples from this area, and the majority of positive tests 
was obtained from samples collected at low water, while many samples 
taken on the flood tide did not contain fecal bacteria of any sort. 
Five miles below Fields Point, still fewer samples contain 3. coli, 6 
miles below this organism is rarely found. About 50 per cent of the 
samples from the Conimicut Point oyster beds and about 31 per cent 
of those from the Nayatt Point ground contained colon bacilli. The 
eastern shore of the river is cleaner than the western above Conimicut 
Point. Below this point reverse conditions are encountered. No fecal 
bacteria were found in samples collected on the Rocky Point oyster 
ground, over 7 miles distant from Fields Point. 
But ZB. coli was isolated from samples taken near buoy No. 1, 
marking the entrance of the Warren River channel. This station is 
a little over 24 miles distant from the town of Warren, and at the 
same time is far enough out in the Providence River to be just included 
in the are which marks the 8-mile limit from Fields Point. No fecal 
bacteria were found in samples collected near buoy No. 7, however, 
which is 4 miles distant from Warren and about 8} from the Providence 
sewer outlet. Thus it may be stated that 8 miles below the Fields 
Point sewer no colon bacilli have been found in the water of the river, 
and from this point on till it reaches the headwaters of Narragansett 
Bay the river is free from sewage bacteria. 
Passing downstream, the number of colon bacilli in the river water 
decreases gradually from 500 per cubic centimeter one-half mile below 
Fields Point to 1 per cubic centimeter at Conimicut. Below Conimi- 
cut no sewage bacteria were found by the plate method employed in 
this test. 
The water on the Prudence Island and Wickford oyster beds does 
not contain LB. coli. 
The portion of Mount Hope Bay included in the Rhode Island ter- 
ritory is comparatively free from pollution, and the oyster ground in 
this bay is located from 4 to 7 miles below Fall River, the chief source 
of pollution. 2. coli was isolated from a single sample taken in the 
entrance to the bay, but the presence of the organism in this instance 
was probably due to local contamination, for other samples taken near 
by did not give reactions for colon bacteria. 
Samples from Kickemuit River did not contain LB. col/. 
One sample collected on the oyster bed under Warren Neck con- 
tained LB. colt. 
BACTERIOLOGICAL ANALYSIS OF SHELLFISH FROM NARRAGANSETT BAY. 
Methods employed.—Much the same plan of work was employed in 
the examination of the shellfish of Narragansett Bay as was used in the 
water analysis. Oysters, clams, and mussels were first collected on the 
