SYSTEMATIC AND DESCRIPTIVE. 1 97 



in two to three weeks the maximum width of the 

 culture-streak is about 2 to 3 mm. On solidified 

 blood serum the cocci grow as on agar-agar. 

 They do not liquefy any nutrient medium. In 

 a vacuum they rapidly cause the decomposition 

 of white of egg or beef, which are energetically 

 peptonised. They occur in acute abscesses.* 



Streptococcus pyogenes malignus. Fliigge, 

 Cocci occurring singly and in chains. They 

 grow very slowly in nutrient gelatine ; the cultiva- 

 tions closely resemble those of Streptococcus pyogenes. 

 They are pathogenic in mice and rabbits. They 

 were isolated from necrotic patches in the spleen 

 of a fatal case of leukaemia. 



Streptococcus pyogenes aureusf (Staphylo- 

 coccus* pyogenes aureus, Rosen bach. Yellow coccus in 

 pus. Coccus of acute infectious osteomyelitis). Cocci 

 singly, in pairs, short chains, and irregular masses. 

 Cultivated on nutrient agar-agar an orange-yellow 

 culture develops, looking like a streak made with 

 oil paint % (Plate VIIL, Fig. 2). Cultivated in a 

 test-tube of nutrient gelatine, the gelatine is rapidly 

 liquefied, and the growth subsides as an orange- 



* Ogston, Brit. Med. Journ. 1881. 



t These cocci are placed among the Streptococci as they un- 

 doubtedly may occur in small chains of three or four individuals 

 linked together. The form of zoogloea is not considered important. 

 The same applies to the Staphylococcus cereus albus and flavus, 

 which are also placed by the author in the genus Streptococcus. 

 Passet acknowledges that they form long and short chains, but 

 named them Staphylococcus because of the prevalence of irregular 

 zoogloea. 



\ Rosenbach. 



