198 REPORT OF THE COMMISSIONER OF FISHERIES. 
ence of £&. coli in shellfish can be considered an index of fecal con- 
tamination there seems to be considerable difference of opinion. On 
the one hand Klein asserts this to be the case, and states that ‘‘the 
presence of &. col in the oyster is strongly suggestive of fouling of 
the particular sample with material of excremental origin,” while, on 
the other hand, Herdman and Boyce are inclined to accept the state- 
ment with reserve. From the results of the experiments recorded in 
this paper, however, it seems to me that the presence of this organism 
in oysters is a certain indication of sewage contamination. 
It was partially due to the interest stimulated by the splendid paper 
on ‘‘Oysters and Disease,” by Prof. W. A. Herdman and Rupert 
Boyce, of Liverpool, England, that the present investigations were 
undertaken. At that time the city of Providence was discharging, 
daily, large quantities of ‘‘ untreated” sewage into the Providence 
River. It is in this body of water that most of the so-called ‘‘ Provi- 
dence River oysters” are raised for market. Besides the sewage of 
Providence, the drains of numerous summer residences and shore 
resorts located on the river banks also contribute to the general pollu- 
tion of these waters, and the sewage of the city of Fall River is a 
possible source of contamination to certain oyster beds situated in 
Mount Hope Bay. 
Here, then, was an interesting and practically unexplored field for 
research, the careful study of which might throw some light on the 
question of sewage pollution of tidal waters and the contamination of 
shellfish growing therein. The experiments were begun in the fall of 
1899, and continued through a period of about three years. The end 
in view was twofold: First, to obtain by bacteriological examination 
some definite knowledge of the extent of the pollution of these waters, 
and, second, to determine, also by bacteriological methods, the pres- 
ence of sewage in oysters and other shellfish from various regions of 
the bay. Bacillus coli was taken as an indicator of sewage pollution, 
and samples containing this organism were considered to be contami- 
nated by sewage. 
The work was carried on at the Anatomical Laboratory of Brown 
University, under the direction of Prof. F. P. Gorham, to whom I 
desire to express especial gratitude for assistance and guidance 
throughout the entire investigation. I wish also to express my sincere 
thanks to Dr. A. D. Mead, of Brown University, and to Dr. H. C. 
Bumpus, director of the American Museum of Natural History, for 
material assistance and many kindnesses shown me during the prepa- 
ration of this work. 
DESCRIPTION OF NARRAGANSETT BAY. 
The state of Rhode Island has an actual land area of 1,054.6 square 
miles. The waters of Narragansett Bay, with its tributaries, comprise 
