DESCRIPTION OF SPECIES 



395 



cultures have a smell of butyric 

 acid. 



• Milk — At 37° C. becomes slimy 

 and flaky, with weak acid re- 

 action, and a smell of butyric acid. 

 Peptonisation. 

 Non-pathogenic. 



BACILLUS, No. 16 (Adametz). 

 Source and habitat — Milk. 



Morphology — Straight rod ; involution 

 forms ; 3-5 to 5 m long by I to 2 ^ 

 broad. Growing sometimes into 

 long threads. 



Staining reaction — Ordinary aniline 

 stains. 



Motility — N on-mot ile. 



Spore formation — Present. 



Biology : cultural characters {includ- 

 ing biochemical features). 



Gelatine plates — Radiate and 

 arborescent, rapidly - liquefying 

 colonies. In stab - cultures a 

 pellicle appears on the surface of 

 the liquefied medium. 



Agar plates — Show a thin, 

 wrinkled growth. In agar stab 

 there are ramifications of the 

 growth into the medium ; arbore- 

 scent colonies. 



Milk — At 37"" C. rapid gelatinous 

 precipitation occurs through forma- 

 tion of acid, with agreeable smell 

 of cheese. Does not ferment milk- 

 sugar. 



Non-pathogenic. 



BACILLUS, No. 17 (Adametz). 



Source and habitat — Milk, 

 Morphology — 3 to 4 ;u long by i to 



1-2 M broad. Frequently forming 



threads. 

 Staining reaction — Ordinary aniline 



stains. 

 Motility — Non-motile. 

 spore formation — Present. 



Biology: cultural characters {includ- 

 ing biochemical features). 



Gelatine plates — Membraneous, 

 white, irregularly bounded colonies, 

 which rapidly liquefy the medium. 



Agar plates — A wrinkled, slimy 

 layer. 



Milk — At 37° C. becomes rapidly 

 a plastic mass, which changes with 

 shaking into a slimy syrup, with 

 strong acidification and a smell of 

 butyric acid. Does not ferment 

 milk-sugar. 



Non-pathogenic. 



BACILLUS ARBORBSCBNS LACTIS 

 (Conn). 



Source and habitat — Milk. 



Morphology — 1-8 m by 3 m; grows in 

 long chains. 



Staining reeu:tion — Ordinary aniline 

 stains. 



spore formation — Large spores (1-2 jtt 

 by 2 m) ; occurring in centre of 

 bacillus and causing it to swell 

 very much. 



Biology : cultural characters {includ- 

 ing biochemical features). 



Gelatine plates and tubes — Large 

 " felted ground glass " colony which 

 sinks slowly in a shallow pit of 

 liquefied medium. In stab-cultures 

 a thick, ground - glass surface 

 growth which eventually floats on 

 liquefied medium as a tenacious 

 folded scum. 



Agar plates and tubes — ^A re- 

 markably spreading branching 

 mass covering the surface and 

 even growing under the surface. 



Potato — Almost snow-white 

 growth which extends into the 

 potato. The surface is raised into 

 folded mounds. 



Milk — Is rapidly curdled at 

 20° C. and 35° C, and digested into 

 a cloudy or amber coloured liquid 

 with alkaline reaction. Butter made 



