that the pathogenic varieties cause a much greater hemolysis 

 than the nonpathogenic varieties. 



Schottm filler, in his investigations on the relative hemolytic 

 action of various strains of streptococci, found that the virulent 

 pathogenic streptococci cause abundant hemolysis, the strep- 

 tococcus mucosus shows hemolytic action after many days and 

 the pneumococcus shoAvs only a narrow area of greenish hue 

 surrounding the colony. Schlesinger 7 obtained no hemolysis 

 with the nonpathogenic varieties, while the pathogenic strains 

 possessed abundant hemolytic power. When the virulence of 

 the germ was increased by passage through animals the hemo- 

 lysis is increased. 



In my experiments, I withdrew blood under sterile precau- 

 tions from the jugular of a horse and used it for making blood 

 a gar plates. After solidifying, these plates were inoculated with 

 the milk streptococci. In no instance did any of these organisms 

 show any hemolysis. A contamination from the air in two of 

 the plates produced a beautiful decoloration, this fact being 

 mentioned to indicate that the media was favorable for this 

 action. If we are able to draw any conclusions from these re- 

 sults, it must be that these streptococci are different from the 

 common pathogenic varieties or else they are in such an attenu- 

 ated condition that this property has been lost. 



FILTERED BEEF-TEA CULTURES. 



No attempt was made to grow these strains in filtered beef-tea 

 cultures of the streptococcus because the results of various 

 authors working on the streptococcus pyogenes present such 

 conflicting results that one would not be able to draw any satis- 

 factory conclusions from such an investigation. 



NEUTRAL RED. 



Gordon 8 has used neutral red for differentiation of strepto- 

 cocci. When grown under anaerobic conditions forty-eight hours 

 at .>7 he found the streptococcus brevus reacted positive, while 

 streptococcus longus and pyogenes reacted negative. This, how- 



