486 



WILBURT C. DAVISON 



COMPARISON OF BACTERIOLYTIC ACTIVITY OF BACTERIOLYSANT 



AGAINST SALINE AND PEPTONE WATER SUSPENSIONS 



OF NORMAL DYSENTERY BACILLI 



Bacteriolysants were equally active against normal dysentery 

 bacilli suspended in 0.9 per cent saline and 1 per cent peptone 

 water provided the reactions of the two suspensions were the 

 same (table 7). It is possible that earher reports (Da\'ison, 

 1922) of the failure of bacteriophages to lyse sahne suspensions 

 of dysentery baciUi may be explained by the fact that the reac- 

 tion of the sahne used, was too far from the optimum. 



TABLE 6 

 The effect of the reaction of the media in which dysentery bacilli were grown, on the 

 degree of lysis produced in a culture by a bacteriolysant 



RESISTANCE OF OLD PEPTONE WATER CULTURES TO 

 BACTERIOLYSANTS 



As shown in table 8, bacteriolysants had no bacteriolytic 

 activity against a one hundred and thirty-day-old peptone water 

 culture of normal Flexner Y bacilli. There are at least four 

 explanations for this failure, i.e., (1) that the reaction of the cul- 

 ture was too far from the optimum, (2) that the culture contained 

 so many organisms that the lytic principle was adsorbed bj^ 

 the bacterial bodies, (3) that the organisms were all "resist- 

 ant" and (4) that the culture was dead. However, its reaction 

 was pH 8.0 which is at or near the optimum. The concentra- 



