IDENTITY OF THE LACTIC-ACID STREPTOCOCCUS 



163 



In this graph only the test substances are given which showed a 

 difference of at least 5 per cent between the two groups. 



From this it is evident that aside from sucrose none of the 

 substances show sufficient difference to be of differential value. 

 Exception might be taken to this statement in the case of malt- 

 ose, in which all of the udder streptococci reacted positively 

 while about one-fourth of the cultures of the other group were 

 negative, but this could hardly be considered of great value for 

 purposes of identification. Though none of the udder cultures 

 of this collection fermented mannit, that fact is probably of no 



TABLE 3 

 Fermentation of test substances 



significance from the point of view of classification because it is 

 well known that the ability to attack this substance is not 

 uncommon among streptococci of the pyogenes type. In the 

 work of Rogers and Dahlberg (1914) about one-fourth of the 

 udder streptococci (from infected udders) fermented mannit, 

 and this character was also common among cultures from other 

 sources. 



Though having no relation to the purpose of this paper, it 

 is interesting to note that among the udder organisms all of the 

 six cultures from one cow (no. 631) fermented salicin while only 



