250 BACTERIOLOGY 



CLASS VII. WITHOUT ENDOSPORES. AEROBIC AND FACULTATIVE 

 ANAEROBIC. CHROMOGENIC; PIGMENT YELLOWISH. GELATIN 

 LIQUEFIED. 

 I. Gelatin colonies conglomerate warty. 



123. B. citreus (Unna-Tommasoli) Kruse. 



II. Gelatin colonies simple, not conglomerate or warty. 



A. Liquefaction of the gelatin near the surface in gelatin stab cultures, i.e. 



crateriform stratiform. 

 1230. B. Rheni. 



124. B. aurescens Ravenel. 



125. B. cuticularis Tils. 



B. Liquefaction of the gelatin along the entire length of the needle in stab 



cultures, i.e. funnel-formed saccate. 



1 . Gelatin liquefied very slowly. 



126. B. tremelloides Tils. 



2. Gelatin liquefied rapidly. 



127. B. Kornii. 



128. B. Schirokikhi. 



III. Gelatin colonies ameboid, proteus-like to zooglcea masses. 



129. B. dianthi Arthur-Bolley. 



IV. Gelatin colonies not described. 



A. Milk coagulated, at least on boiling. 



130. B. Hudsoni Dyar. 



B. Milk not coagulated. 



1. Nitrates reduced to nitrites. 



131. B. theta Dyar. 



2. Nitrates not reduced to nitrites. 



132. B. gamma Dyar. 



123. B. citreus (Unna-Tommasoli) Kruse 



Ascobacillus citreus Unna-Tommasoli : Monatschrift f. prakt. Dermatol., IX, 60. 

 B. citreus Kruse : Fliigge, Die Mikroorganismen, 1896, 489. 



Morphology. Bacilli 0.3 : 1.3 ^ ; occur singly or in bundles. 



Gelatin colonies. Conglomerations of small spheres. 



Gelatin stab. Small flakes in the liquefied funnel ; on the surface a slimy 



citron-yellow layer. 



Agar slant. Growth abundant, with honey-drop-like protuberances. 

 Potato. Growth slimy, citron-yellow, becoming in 2 weeks greenish yellow. 

 Habitat. Isolated from the surface of the human body in eczema. 



