56 



MARGARET C. PERRY AND W. F. MONFORT 



and of animals none were Bad. aerogenes. To his references 

 may be added Hulton (1916), Stokes (1919) and Rettger and 

 Chen (1919) who encountered no organisms of the Bad. aerogenes 

 type in 173 cultures isolated from feces. 



Far from being a specific reagent for members of the aero- 

 genes-cloacae group, adonitol probably deserves a place not 

 much superior to dulcitol as a reagent of rather dubious import 

 in discriminating members of the low ratio group. Winslow, 

 Kligler and Rothberg (1919) summarize the earlier work of 

 Kligler (1914) and Levine (1918) in tabular form, to which we 

 add in parentheses the less usual reactions of these and the high 

 ratio types: 



Bad. areogenes 



Bad. doacae 



Bad. neapolitanus 

 Bad. communior. . 



Bad. coli 



Bad. acidi-ladici . 



Adonitol is important as being sometimes included in the list of 

 sugars, etc., fermented by Bad. aerogenes, which Winslow and 

 his co-workers consider as perhaps the most primitive of the 

 colon-typhoid group, and of the highest fermentative power. As 

 such it is least significant as an indicator of fecal pollution. The 

 significance of the so-called ''fecal aerogenes type" in waters is 

 probably slight. 



DEPARTURES FROM STANDARD METHODS 



Because of the shortage of Witte's peptone and the impossi- 

 bility of obtaining material for the synthetic medium of Clark 

 and Lubs (1917) for testing the methyl red reaction, Difco pep- 

 tone was substituted in the initial determinations. Preliminary 

 tests on pure cultures with 0.75 per cent Difco, properly buffered, 

 and incubated at 30°C. for two days, gave results identical with 

 those of the same cultures in the standard Witte broth. As the 

 number of strains isolated increased, tests were repeated with 



