SEA-FISHERIES LABORATORY. 185 



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 

 o 



