LACTOSE FERMENTING ANAEROBES 563 



coll, applied for wafers of the southeastern area of the United 

 States, may not be apphcable to waters of the northern and 

 western areas of the country. Thus the anaerobes which we, 

 have been able to observe, have not in a single instance produced 

 gas in the butt of Endo tubes. On the other hand, it is likely 

 that anaerobes found in waters in other parts of the country 

 might possess this ability. 



The ideal procedure for the differentiation of anaerobic lac- 

 tose fermenting organisms from B. coli should not only establish 

 the absence of B. coli, but permit the isolation of the anaerobe 

 as well. Simonds and Kendall (1912) and Jones (1916) have 

 described good procedures for the isolation of anaerobes in pure 

 culture. The application of these methods to the isolation of 

 anaerobes found in water, would provide valuable scientific data. 

 The practical worker, however, would probably find the isolation 

 of anaerobes by either of these methods not commensurable with 

 the work involved, since the mere isolation of a lactose fermen- 

 ting anaerobe would not rule out the possible presence of B. coli, 

 and it is this fact that the worker is primarily interested in. 



It might be added that it is questionable whether 'anae- 

 robes" is a proper term to apply to non-colon lactose fermenting 

 organisms found in water. We have twice transplanted spread- 

 ing growths from Endo plates into lactose fermentation tubes 

 which resulted in gas formation in these tubes after incubation. 

 These growths on the Endo plates could readily be distinguished 

 as non-colon types. It is evident, however, that not all non- 

 colon lactose fermenters, are anaerobes. Meyer (1918) has 

 recently reported the finding of a lactose fermenting organism 

 in water, capable of growing aerobically. 



RESUME 



1. Anaerobic lactose fermenting organisms found in waters of 

 the Southeastern area of the United States, appear to be unable 

 to produce gas when grown anaerobically in Endo medium. 

 In accordance with this finding, the differentiation of anaerobes, 

 from B. coli, is accomplished as follows: 



THE JOURNAL OF BACTERIOLOGT, VOL. Ill, NO. 6 



