The Significance of B. Coli in Water. 119 



into guinea pigs. In Germany, Papasotiriu (Papasotiriu, 

 1 901) was meanwhile carrying on almost exactly similar 

 investigations to Prescott's, with identical restilts. 



Other testimony is somewhat conflicting with regard 

 to the occurrence of B. coli on plants. Klein and Houston 

 (1900) reported the finding of typical colon bacilli in only 

 3 out of 24 samples of wheat and oats obtained from a 

 wholesale house; rice, flour, and oatmeal bought at two 

 different retail shops gave B. coli in all three cereals 

 in one case and none in the other. Clark and Gage 

 (1903) were unable to isolate B. coli from standing grains. 

 Gordan (1904) could not find ]^. coli in .1 and .01 mg. 

 samples of clean bran, but isolated it easily from that 

 of poor quality. Winslow and Walker (1907) have 

 recently reported the examination of 178 samples of grain 

 and 40 samples of grasses for B. coli without success. On 

 the other hand, Diiggeli (1904) found B. coli among 

 the bacteria occurring on the leaves of growing plants, 

 although it was not one of the most abundant species. 

 Barthel, too (Barthel, 1906), found B. coli widely dis- 

 tributed on plants from both cultivated and uncultivated 

 regions; 



These results raise the interesting questions: Is it 

 possible that the lactic-acid bacilli and the similar forms 

 found on plants have been indirectly derived from animal 

 intestines, having "escaped from cultivation," as the 

 botanists say? Or is the converse true, namely, that all 

 colon bacilli are simply plant parasites which have found 



