n6 Elements of Water Bacteriology. 



considered that caution should be exercised in condemn- 

 ing a water on account of the presence of B. coli, except, 

 as he added, "for those cases where it exists in consider- 

 able quantity." 



Certain Italian observers appear to have come to even 

 less conservative conclusions. Abba (Abba, 1895) found 

 colon bacilli constantly present in unpolluted waters near 

 Turin. Moroni (Moroni, 1898; Moroni, 1899) reported 

 the examination of numerous deep and shallow wells and 

 unpolluted springs about Parma, as well as of the public 

 water-supply of the city, and concluded that the colon 

 bacillus was a water form and had no sanitary significance. 

 The characters used for the identification of the species 

 in this case were fairly exhaustive, but both Abba and 

 Moroni used liter samples for analysis. 



Levy and Bruns (Levy and Bruns, 1899) gave a new 

 turn to the discussion by emphasizing the importance of 

 animal inoculation, already suggested by Blachstein 

 (Blachstein, 1893) and others. They claimed that the 

 existence of numerous para-colon and par^-typhoid or- 

 ganisms in air, in dust, and in unpolluted water made it 

 impossible to decide by ordinary bacteriological methods 

 whether true colon bacilli were present in water or not. 

 In no case, however, did representatives of the colon group 

 isolated by them from water kill a guinea pig, even when 

 i or 2 c.c. were injected intraperitoneally. The authors, 

 therefore, considered pathogenicity as an attribute belong- 

 ing only to the true B. coli of the intestine. This paper 



