AUROCOCCUS 



931 



Shottmuller's Classification of the Genus Streptococcus. — This is 

 very simple, and is based on the characters of colonies on blood-agar plates. 



1. Colonies surrounded by a clear zone of haemolysis — S. hcsmolyticus 

 ( = 5. pyogenes = S . erysipelatos = S. erysipelatosns). 



2. Colonies not surrounded by a clear zone of haemolysis; of a peculiar 

 greenish colour — S. viridans {=S. mitior). 



3. Colonies whitish, slimy, somewhat adherent to the medium (cocci 

 capsulated) — 5. mucosus. 



Genus Aurococcus Winslow and Rogers, 1905. 



Definition. — Streptococcese parasitic, producing pigment, and in 

 irregular groups or in non-capsulated groups of four, or in pairs, but 

 never in zoogloea masses. Growth good. Sugars fermented with 

 formation of a moderate amount of acid, but no gas. May or may 

 not reduce nitrates and liquefy gelatine. 



Type Species. — Aurococcus aureus (Rosenbach, 1884). 



Classification. — Winslow and Rogers, after a long discussion of 

 synonyms, have recognized only three types, which may be differen- 

 tiated as follows: — 



A. Nitrates not reduced : — 



1) Gelatine strongly liquefied — Aurococcus aureus (Rosenhaich., 1884). 



2) Gelatine not liquefied — Aurococcus aurantiacus (Cohn, 1872), 



B. Nitrates reduced: — • 



(3) Gelatine may or may not be liquefied — Aurococcus mollis (Dyar 

 1895)- 



Remarks. — -This group is of great interest in the tropics, as its 

 members are the cause of boils and pyosis in various parts — e.g., 

 Aurococcus mollis causes Nile boils and pyosis Corletti. 



With regard to ' pyosis Mansoni,' Castellani in Ceylon showed it 

 to be caused by a species of aurococcus, which Clegg and Wherry 

 in 1906 called Micrococcus pemphigicontagiosi , which seems to be 

 the same as that named Micrococcus pemphigineonatorum by 

 Almquist in igoi, and both may be Aurococcus mollis. Aurococcus 

 tropicus Chalmers and O'Farrell, 1913, found in Castellani's 

 ' pyosis tropica,' appears to be different, as its vaccine was without 

 effect on a case of Nile Boils, but, unfortunately, it was not possible 

 to test it on nitrates and gelatine. 



TRIBE II. MICROGOCCEiE Trevisan, 1889, emendavit Winslow and 



Rogers, 1905. 



Genus Rhodococcus Winslow and Rogers, 1905. 



Definition. — Micrococceae, usually saprophytes, rarely parasites, 

 with cells in groups or regular packets. Generally more or less 

 decolourized by Gram. Growth on agar abundant, with the 

 formation of red pigment. Very slight fermentative action. 

 Gelatine rarely liquefied. Generally reduce nitrates to nitrites. 



Type. — Rhodococcus roseus (Flugge, 1886), emendavit Dyar, 1895. 



Remarks. — Winslow and Rogers recognize, in addition to the 

 type, R. fulvus Cohn, 1875, and they leave the rest in groups to 

 await further investigation. 



We add Rhodococcus castellanii, discovered by Castellani and 



