142 ELEMENTS OF WATER BACTERIOLOGY 



rats, earthworms, moles, fowls, swallows, sparrows, 

 ducks, pigeons, geese, a jackdaw, a redstart, a blackbird, 

 an adder, and a trout. Three out of 5 guinea pig 

 samples, 4 out of 20 horse samples, 2 out of 3 mouse 

 samples, 3 out of 8 rabbit samples, and 2 out of 8 

 earthworm samples, 14 in all, were negative; while 

 all the rest showed B. coli. 



In cold-blooded animals the occurrence of B. coli is 

 less constant. Negative results in the frog and positive 

 results in certain fishes, an adder and earthworms have 

 just been quoted. Amyot (1902) failed to find the 

 organism in the intestines of 23 fish representing 14 

 species. Johnson, on the other hand (Johnson, 1904), 

 in the examination of the stomach and intestines of 

 67 fish caught in the polluted Illinois and Mississippi 

 Rivers, isolated B. coli 47 times. He concluded from 

 these results that the migration of fish from a con- 

 taminated stream or lake to an unpolluted one may 

 explain the occasional finding of B. coli in small samples, 

 or the more regular detection of it in large volumes 

 of the water. 



Bettencourt and Borges (i9o8 b ) isolated 29 cultures 

 of colon-like microbes from the intestines of 17 types 

 of fishes, reptiles and amphibia. Only 8 of the 29 

 formed gas in lactose broth and only 2 (from an eel 

 and an adder) proved to be typical B. coli. It should 

 be noted, however, that the samples of faecal material 

 were plated directly on Endo medium instead of being 

 subjected to the more sensitive process of preliminary 

 enrichment. 



Fromme (1910) reviews the work of many observers 



