105 
Since that date other samples of mussels from various 
beds have been examined bacteriologically in our laboratory, 
and in these also extensive pollution by sewage organisms 
has been demonstrated. I wish to state that in all cases in 
which sewage contamination has been reported we have 
not relied upon the bacteriological evidence alone. We 
have used it as the corroboration, not as the sole proof. 
It is evident to anyone who has watched recent 
investigations that we must have still further knowledge in 
regard to the distribution of the organisms of the “coli” 
group in nature, and of the bacteriology of the absolutely 
clean shellfish before we can place implicit trust in bacterio- 
logical results taken alone. Professor C. A. Fuller, of 
Brown University in the United States, read a paper on 
“The bacterial flora of the Oyster’s intestine,” before the 
Society of American Bacteriologists, in March, 1903, in 
which he gave the results of extensive studies of the oysters 
of Narragansett Bay. He found that the ‘ coli”’ organisms 
do not occur in oysters from clean sea water far from shore, 
but are present in those nearer land and in less pure water. 
He concludes “ From the results of these experiments it 
appears that the colon bacillus is not normally present in 
the intestine of oysters, and when present always indicates 
contamination.” 
Also Miss Chick shows (Thompson-Yates Reports, 
vol. 3, pt. 1, pp. 1-29, and pt. 2, pp. 117-129) B.coli is not 
found at all in any unpolluted soils and fresh waters. 
When it was found there was always other evidence of 
sewage pollution. It was not found in dry road dust. It 
does not withstand even a short exposure to drying. (If 
it is found in the sea it apparently always comes from 
polluted land drainage). 
On the other hand, in the recently issued Fourth 
Report of the Royal Commission on Sewage (1904) we 
H 
