168 BACTERIOLOGY 



122. Bact. aeris-minutissimum (Kruse) 



Fltigge, Die Mikroorganismen, 1896, 441. 



From descriptions, indistinguishable from the preceding, except that it pro- 

 duces pigment a little less strongly. 

 Habitat. Isolated from the air. 



123. Bact. dormitor (Wright) 



B. dormitor Wright : I.e., 442. 



Morphology. Bacilli of medium size, with conical ends ; variable, long pairs 

 and filaments. 



Gelatin colonies. In 2 days, yellowish points, 1 mm. ; microscopically, yellow- 

 ish, slightly granular ; rough, sharp, bulging outlines, surrounded by a 

 zone of liquefied gelatin. 



Gelatin stab. A funnel of liquefaction, turbid ; sediment bright yellow. 



Agar slant. Growth glistening, translucent, yellowish. 



Bouillon. Turbid ; yellowish sediment, and a slight pellicle. 



Litmus milk. Decolorized, amphoteric. 



Glucose bouillon. No gas. Indol negative. No growth at 36 . 



Habitat. Water. 



CLASS VI. WITHOUT ENDOSPORES. AEROBIC AND FACULTATIVE 

 ANAEROBIC. PRODUCE PIGMENT ON GELATIN OR AGAR- PIG- 

 MENT YELLOWISH. GELATIN NOT LIQUEFIED. 



I. Chromogenic function weak, pale or grayish yellow. 



A. Gelatin colonies beset with thorny outgrowths when old. 



124. Bact. spiniferutn (Tommasoli). 



B. Gelatin colonies not characterized as above. 

 I. Litmus milk reddened, or rendered acid. 



a. Nitrates reduced to nitrites. 



* Milk coagulated after a long time by boiling. 



125. Bact. subochraceum (Dyar). 

 ** Milk not coagulated. 



126. Bact. domesticum (Dyar). 



127. Bact. amabilis (Dyar). 



b. Nitrates not reduced to nitrites. 



128. Bact. lacunatum (Wright). 



