NON-PATHOGENIC BACILLI. ' 645 



granular at the margins, and have a smooth contour. In gelatin stick 

 cultures the superficial growth is like a drop of milk in appearance; very 

 scanty growth along the line of puncture at first, later a row of spherical 

 colonies is seen ; the surface growth in old cultures has a slightly reddish 

 tint. Upon the surface of agar a thin, transparent, grayish- white layer 

 with smooth margins. Upon potato an abundant layer is developed. 



298. BACILLUS ALBUS (Eisenberg). 



Found in water. 



Morphology. Short bacilli with blunt ends, often united in short chains. 



Biological Characters. An aerobic, non-liquefying, motile bacillus. 

 Spore formation not observed. Grows slowly at the room temperature 

 not in the incubator at 37 C. Upon gelatin plates forms round, white 

 colonies the size of a pin's head. In gelatin stick cultures grows slowly, 

 forming a white line along the puncture and a small, button-like, white 

 mass at the point of entrance. Upon the surface of agar forms a milk- 

 white layer. Upon potato a dirty yellowish-white growth, limited to the 

 line of inoculation. 



299. BACILLUS ACIDI LACTICI (Hueppe). 



Found in sour milk. 



Morphology. Bacilli from 1 to 1.7 V long and from 0.3 to 0.4/* broad; 

 usually in pairs, sometimes in chains of four. 



Biological Characters. An aerobic and facultative anaerobic, non- 

 liquefying, non-motile bacillus. Forms spherical spores, which are located 

 at the ends of the rods. Grows slowly at the room temperature in the usual 

 culture media. Upon gelatin plates forms small, white, punctiform colonies, 

 which later develop into shining, porcelain-colored discs with a transparent 

 margin; under a low power they have a yellowish tint in the centre and 

 thin, irregular margins. In gelatin stick cultures small colonies are de- 

 veloped along the line of puncture, and later a dry, glistening, soft, grayish- 

 white, and tolerably thick layer is developed upon the surface. Upon potato 

 an extended, yellowish-brown layer is formed. In. milk lactic acid is pro- 

 duced, the casein is precipitated, and carbon dioxide is given off. 



300. BACILLUS LIMBATUS ACIDI LACTICI (Marpmann). 



Found in fresh cow's milk. 



Morphology. Short, thick bacilli, usually in pairs; every rod is sur- 

 rounded by a capsule which is not stained by the aniline colors. 



Biological Characters. An aerobic, non-liquefying, non-motile bacil- 

 lus. Does riot form spores. Grows slowly in the usual culture media at 

 the room temperature also in the incubator. Upon gelatin plates, at the 

 end of twenty-four hours, forms milk-white, punctiform colonies. In gela- 

 tin stick cultures scanty development occurs along the line of puncture, 

 and upon the surface a flat, irregular layer of a white, pus-like color is 

 formed. In milk, at the end of twelve hours, a slightly reddish color is 

 seen; at the end of twenty -four hours coagulation of the casein and a 

 strongly acid reaction lactic acid ; does not produce gas. 



301. BACILLUS LACTIS PITUITOSI. 



Synonym. Bacillus der schleimigen Milch (Loffler). 

 Found in milk. 



Morphology. Tolerably thick, slightly curved bacilli, which very quick- 

 ly break up into small segments resembling micrococci. 



Biological Characters. An aerobic, non-liquefying bacillus. Grows 



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