[SADLER-MOUNCE-SHANLY] WORK ON BACTERIOLOGY 139 



reports a strain of the hog cholera bacillus {B. suispestifer) obtained 

 from McFadyean, which failed to ferment dulcite; this organism also 

 failed to ferment maltose, while our cultures are positive to maltose. 

 Jordan^ reports that several stock cultures of B. suispestifer have 

 failed to ferment dulcite. Savage,^ in his classification of the Gaertner 

 group, describes a number of strains which are in many respects 

 similar to the true Gaertner, but which do not ferment dulcite, as 

 Para-Gaertner bacilli. Whether our cultures 8 and 24 would have 

 fermented dulcite when freshly isolated, is a matter upon which we 

 have no evidence. As at the present time we have no sera specific 

 for the several variations and are therefore unable to confirm with the 

 agglutination test; and as our strains do not produce acid and gas 

 from dulcite, we classify cultures 8 and 24 as varieties of the Para- 

 Gaertner group after Savage^. 



Note: — On reference to the data accumulated at the time the material was 

 collected, we find that Cultures 8 and 24 were isolated from herrings caught in a 

 weir which was reported to be subject to sewage contamination. 



An Observation on the Methyl Red Reaction 



We consider it important to make special mention of the re- 

 action of our cultures to Methyl Red. During the last few years, 

 evidence has accumulated to show that faecal strains — from bovine 

 sources — of B. coli, give an acid reaction to Methyl Red; and that 

 non-faecal strains of B. coli — from grains — give an alkaline reaction 

 to Methyl Red. The former are recorded as the organisms of the 

 low-ratio group; the latter as the organisms of the high-ratio group. 

 The philosophy of the reaction is that Methyl Red differentiates ac- 

 cording to the H+ion concentration. The work is reported by Harden 

 and Walpole;" Rogers; Rogers, Clark and Davis ;^^ Rogers, Clark and 

 Evans ;*^ Clarke and Lubs;^^ Levine^^, and others. 



A reference to the data recorded by us in this paper, reveals the 

 fact that without exception the cultures isolated from the intestines 

 of herrings have given an acid reaction to Methyl Red. Some of these 

 cultures are types of B. vulgaris, some are typical strains of B. coli, 

 while some are organisms of the Para-Gaertner group. Culture 17 

 is from the pickle tank, but isolated from the pickle immediately 

 after the tank had received its quota of fresh herrings. 



On the other hand, the cultures we have isolated from water in 

 the weirs have all proved to the alkaline to Methyl Red. We have 

 repeatedly confirmed these reactions. This is not the place to enter 

 upon any discussion. 



