222 MANUAL OF BACTERIOLOGY. 



singly or in various combinations ; does not liquefy gelatin ; 

 facultative anaerobic; grows rapidly, best at 30 to 33 C. ; 

 grows on ordinary gelatin, but best on special media; it 

 decomposes urea, producing ammonia and carbon dioxide, 

 which form ammonium carbonate. 



Sarcinae. There is a large number of species of sarcinse. 

 They are common organisms in the air. They frequently 

 contaminate plate-cultures. Many of the sarcinae of the 

 air present, in cultures, growths having brilliant colors, 

 from which some of them are named ; thus there are orange, 

 yellow, rose-colored and white sarcinae, and others. 



Sarcina pulmonum. Found in the air passages of man; 

 I to 1.5 /J. in diameter, occurring in tetrads or cubes of eight 

 cells; aerobic; does not liquefy gelatin; grows slowly, best 

 at ordinary temperatures, preferably upon gelatin. It de- 

 composes urine with the formation of ammonia. It is said 

 to form endogenous spores which are extremely resistant 

 to heat. 



Sarcina ventriculi. Found in the stomachs of man and 

 of animals; 2.5^ in diameter, occurring in cubes of eight 

 cells or more; it does not liquefy gelatin; aerobic; grows 

 on ordinary culture-media; the growths tend to become 

 yellow. Small numbers of sarcinre may occur in the normal 

 human stomach ; the presence of large numbers indicates the 

 existence of abnormal fermentative processes. 



Bacillus fluorescens liquefaciens. Found in water and 

 putrid fluids; very common; appears as a small rod, actively 

 motile; aerobic, but somewhat variably; liquefies gelatin; 

 grows rapidly at ordinary temperatures upon the usual cul- 

 ture-media. It forms a pigment having a beautiful greenish- 

 yellow fluorescence, best seen in transparent media ; the 

 growth on potato has a brown color. Does not stain by 

 Gram's method and does not form spores. 



Bacillus fluorescens putidus. Found in water; a short 

 rod with rounded ends; actively motile; does not liquefy 



