CHAPTER VII. 



SIGNIFICANCE OF THE PRESENCE OF B. COLI IN WATER. 



FIFTEEN years ago the B. coli of Escherich occupied a 

 position of very great prominence in the eyes of sani- 

 tarians. If it was not considered to be in itself a danger- 

 ously pathogenic germ, it was at least regarded as a 

 suspiciously close relation of the typhoid organism. At 

 this time, the alleged presence of either of these forms 

 was quite sufficient to condemn a water-supply. 



Investigation soon showed, however, that the Bacillus 

 coli was by no means confined to the human intestine. 

 Dyar and Keith (Dyar and Keith, 1893) found it to be 

 the prevailing intestinal form in the cat, dog, hog, and 

 cow. About the same time, Fremlin (Fremlin, 1893) 

 found colon bacilli in the feces of dogs, mice, and rabbits, 

 but not in those of rats, guinea pigs, and pigeons. Smith 

 (Smith, 1895) recorded the presence of the organism, in 

 almost pure cultures, in the intestines of dogs, cats, swine, 

 and cattle; and he also found it in the organs of fowls 

 and turkeys after death. Brotzu (Brotzu, 1895) reported 

 B. coli and allied forms as very abundant in the intestine 

 of the dog; and Belitzer (Belitzer, 1899) isolated typical 

 colon bacilli from the intestinal contents of horses, cattle, 



