DESCRIPTION OF SPECIES 



427 



ences Conn named them as varie- 

 ties. Some of the individual 

 elements show square ends ; i /t 

 by 2 /i ; grows in long chains and 

 threads. 



Staining reaction — Ordinary aniline 

 stains. 



Capsule — A well-marked capsule. 



Spore formation — Oval spores in 

 centre of bacillus, becoming very 

 prominent. 



Biology : cultural characters {includ- 

 ing biochemical features). 



Gelatine plates and tubes — No. i 

 produces a proteus-like colony. 

 Liquefaction. In stab cultures a 

 narrow funnel with dense deposit. 

 No. 2 forms a tangled mass of 

 threads like anthrax colonies. 

 Liquefaction. No. 3, radiating 

 growth in stab-culture, obliquely 

 placed. 



Agar plates and tubes — No. i, 

 tough, dry growth easily broken 

 into fragments ; later becomes very 

 white from being covered with 

 spores. No. 2, tough white growth 

 breaking into lumps. 



Potato — No. I, dry, rough, snow- 

 white growth. No. 2, thin, dry, 

 putty-like growth. No. 3, a velvety 

 growth spreading over surface, later 

 becomes very white and dry. 



Milk — No. I, curdles in 2 days 

 at 20° or 36° C. into soft alkaline 

 curd. Digests slowly, producing 

 a rancid odour. No effect on 

 butter. No. 2, curdles rapidly at 

 36°, slowly at 20'' C, digests into a 

 cloudy liquid which is colourless or 

 amber coloured. 

 Non-pathogenic. 



BACILLUS PALLESOBNS (Henrici). 



Isolated from cheese. Non-motile 

 short rods ; i n thick, singly or in 

 pairs. Sometimes grows like 

 B. cerogenes, but less superficially. 



Gas formation. Bouillon remains 

 clear with sedimentation. B. 

 pallens vesiculosum and castellum 

 of the same author differ only from 

 the above in that they make 

 bouillon turbid with formation of 

 surface membrane. 



BACILLUS PRODIGIOSUS. 



Source and habitat — On starchy sub- 

 stances, especially in autumn. 



Morphology — Very short bacillus like 

 a micrococcus (hence Micrococcus 

 prodigiosus) pointed or rounded 

 ends ; about i m long. Sometimes 

 in bouillon long forms and even 

 threads occur. 



Staining reaction — Ordinary stains ; 

 not by Gram's method. 



Flagellaj motility — Active motility ; 

 6 to 8 long flagella ; old cultures 

 non-motile. 



Biology : cultural characters {includ- 

 ing biochemical features) — Best 

 growth at 22^ to 25" C; no pigment 

 at 37° C. 



Bouillon — Diffuse marked tur- 

 bidity, with a delicate pellicle which 

 may be red coloured. The bouillon 

 eventually becomes oily. Red 

 deposit. 



Gelatine plates and tubes — Grey- 

 ish-white round colonies ; rapid 

 liquefaction. Original colonies 

 became red beginning in the centre. 

 Some markings may occur on the 

 colony. Atypical forms also occur. 

 In stab-cultures liquefaction begins 

 in 6 hours in saucer form. White 

 or red flocculi occur. Eventually 

 a deep red deposit appears at 

 bottom of liquefied cylinder. 



Agar plates a?id tubes — Small 

 red colonies after 36 to 48 hours ; 

 irregularly round ; colonies become 

 brown and then may lose their 

 colour. Thread-like growth with- 

 out nodules occurs in stab-cultures. 

 Agar becomes tinted. 



