572 ANAEROBIC ORGANISMS IN GANGRENE 



Morphology. The Bacillus ramosus is a small slender non-motile bacillus, 

 a little larger than the bacillus of mouse septicaemia, occurring singly, or in 

 pairs parallel to one another or at an acute angle. In cultures it is often 



longer, and then has somewhat the appearance 

 of the diphtheria bacillus. Occasionally the 

 bacilli are arranged end to end forming long 

 filamentous chains ; and branching forms have 

 been described. It does not appear to produce 

 spores. 



L "\ ' *^^ Staining reactions. - The Bacillus ramosus 



( ^^-v 1\ C stains easily with carbol-violet and is gram- 

 J. ' S- positive. 



Cultural characteristics. The Bacillus ramosus 

 is .a strict anaerobe ; it grows on the ordinary 

 media and best between 33 C. and 39 C. Cul- 

 tures grow slowly and are scanty and have a fetid 

 ZuberT SM odour. The bacillus produces" a little gas and 



retains its vitality for a long time. 

 Broth. Uniform turbidity. 

 Gelatin. No growth. 



Agar. Isolated colonies are small, rounded or cuneiform, with regular 

 edges. 



Milk. Milk is coagulated ; the casein is not attacked. 



IV. BACILLUS SERPENS. 



The Bacillus serpens was found by Veillon and Zuber in pus from a mastoid 

 abscess, by Hist and Guillemot in gangrene of the lung, and by other observers 

 in similar morbid processes. 



Experimental inoculation. The Bacillus serpens is pathogenic for rabbits, 

 guinea-pigs and mice. In guinea-pigs, sub-cutaneous inoculation is followed 

 by the formation of a fetid abscess and death takes place in about a week. 



Morphology. The Bacillus serpens occurs as large straight rods with 

 rounded ends. In cultures the bacilli are often arranged in pairs end to end, 

 are motile and move with a sort of an undulatory movement. 



Staining reactions. The Bacillus serpens stains easily with the basic aniline 

 dyes containing a mordant. It is gram-negative. 



Cultural characteristics. The Bacillus serpens grows anaerobically on all 

 the ordinary media and at the temperature of the laboratory. Cultures have 

 a fetid odour and give off a little gas. 



Broth. Broth soon becomes cloudy but the growth subsequently precipi- 

 tates and the medium slowly clears. 



Gelatin. Small round greyish colonies appear about the fourth or fifth 

 day. The medium is slowly liquefied. 



Agar. After about 24 hours, isolated colonies appear as small, grey, round, 

 granular points, translucent at first but opaque later. 



V. BACILLUS THETOIDES vel FUNDULIFORMIS. 



This organism was found by Halle in the vagina and in the pus in cases of 

 inflammation of Bartholin's glands, and by Rist and Guillemot in pulmonary 

 gangrene, mastoid abscesses, etc. 



The Bacillus thetoides is described by Veillon and Zuber as B. funduliformis. 



