650 . NON-PATHOGENIC BACILLI. 



ture. Upon potato the growth is rather thin and of a pale-yellow color, 

 not extending far from the line of inoculation. Does not form gas in a sac- 

 charine solution agua coco. 



314. BACILLUS CAVI^E FORTUITUS (Sternberg). 



Obtained, by inoculation in a guinea-pig, from the liver of a yellow- 

 fever cadaver, preserved for forty-eight hours in an antiseptic wrapping. 



Morphology. Bacilli with round ends, from 1 to 4/ long and 0.5 to 0.8 

 // broad; often in pairs. 



Biological Characters. An aerobic and facultative anaerobic, non- 

 liquefying, actively motile bacillus. Spore formation not observed. Grows 

 in the usual culture media at the room temperature. Upon gelatin plates, 

 at the end of three days, the colonies are small, spherical, and under the 

 microscope light-brown in color ; later opaque, or sometimes with an opaque 

 centre surrounded by a transparent zone. In gelatin stick cultures there is. 

 a scanty growth about the point of puncture; growth occurs all along the 

 line of puncture in the form of spherical, translucent, straw colored colo- 

 nies, which have a pearly lustre by reflected light. Upon potato, at the end 

 of a week, development has occurred in the form of small, dirty-yellow 

 masses. Does not form gas in a saccharine liquid agua coco. 



315. BACILLUS COLI siMiLis (Sternberg). 



Obtained from a piece of liver of man kept in an antiseptic wrapping 

 for forty-eight hours. 



Morphology. A bacillus with round ends, from 1 to 3 >" long and from. 

 0.4 to 0.5 p thick; solitary or in pairs. 



Biological Characters. An aerobic and facultative anaerobic, non- 

 liquefying, non-motile bacillus. Spore formation not observed. Grows at 

 the room temperature in the usual culture media better at 37 C. Upon 

 gelatin plates, at the end of two days, the deep colonies are spherical and 

 pale-brown in color; later they become opaque. The superficial colonies are 

 at first translucent, homogeneous, drop-like elevations ; later .they are quite 

 thin and have a pale-brown color. In gelatin stick cultures a translucent 

 growth with irregular margins is developed upon the surface, and a rather 

 scanty line of growth is seen along the track of the inoculating needle. On 

 potato, at 22 C., a thick, dirty -white or pale-brown layer is developed along 

 the impfstrich. Not pathogenic for rabbits or guinea-pigs. 



316. BACILLUS FILIFORMIS HAVANIENSIS (Sternberg). 



Obtained in anaerobic cultures from the liver of a yellow-fever cadaver. 



Morphology. Long and slender bacilli, about 0.3>" in diameter, and 

 forming long, homogeneous filaments in aerobic cultures, while the bacilli 

 are shorter and thicker in anaerobic cultures in glycerin-agar. 



Biological Characters. An anaerobic and facultative aerobic, non- 

 liquefying, non-motile bacillus. Does not form spores. In gelatin stick 

 cultures a scanty growth occurs along the line of puncture ; no growth on the 

 surface. In anaerobic, glycerin-agar roll tubes colonies are developed which 

 are spherical or irregular in outline, of a pale-brown or straw color by trans- 

 mitted light, white and opaque by reflected light ; the superficial colonies 

 are thin and translucent, and have a bluish lustre by reflected light ; later 

 they appear as opaque, cream-like masses with irregular contour. In nutrient 

 agar a scanty, milk-white growth occurs upon the surface and an opaque, 

 branching growth along the line of puncture. No growth upon potato. 

 Grows in neutral bouillon, causing a slight opalescence, and later a scanty 

 white deposit at the bottom of the tuoe. Not pathogenic for rabbits or 

 guinea-pigs. 



