hACJLLI 461 



BACILLUS LIQUEFACIENS 



^LIQU EFIES GELATINE j 



Authority.— Eisenberg, Baktcriologische Diagnostik, 1891, p. 112. The 

 B. liquefaciens described byLustig (Diagnostik der Bakterien des Wassers, 1893, 

 p. 86) resembles very closely the above. 



Where Found. — In water, and occurring very frequently (Lustig). 



Microscopic Appearance.—Short and rather thick bacillus with rounded 

 ends. It is very motile. 



Cultures. — 



Gelatine Plates. —Forms smooth-rimmed circular colonies, with white and 

 slimy contents. Liquefaction produces cup-shaped depressions which rapidly 

 increase in size. After a time an odour of putrefaction is perceptible. 



Gelatine Tubes. — Grows, rapidly forming a funnel-shaped depression, which 

 towards the surface resembles an air-bubble in form. The needle's path in the 

 depth is filled with whitish granular material. 



Agar-agak. — Forms a dirty white expansion. 



Potatoes. — Produces a light yellow growth. 



BACILLUS LIQUIDUS 



I LIQ UEFIES GELAT IN E_[ 



Authority. — Percy and G. C. Frankland, 'Ueber eiiiige typische Mikro- 

 organismen im Wasser u. im Boden,' Zeitschrift filr Hygiene, vol. vi., 1889, 

 p. 382. 



"Where Found. — Very frequently in unfiltered river Thames water. 



Microscopic Appearance.— Short flat bacillus with rounded ends, occurring 

 usually in pairs, the length of such a pair varying between 1*5 fj. and 3*5 m. The 

 dimensions are very variable. It is very motile. No spore foi-mation observed. 



Cultures.— 



Gelatine Plates. — It »forms large cup-shaped liquefying colonies, with 

 almost quite clear and colourless contents. Under a low power the depth 

 colonies are smooth-rimmed and circular. When liquefaction commences the 

 periphery becomes somewhat granular and serrated, and the colonies soon run 

 into each other. 



Gelatine Tubes. — In a few days a broad funnel-shaped depression is visible 

 the whole length of the needle's path, containing turbid liquid and masses of 

 flocculent material. A thin pellicle forms on the surface later, which sinks to 

 the bottom on shaking the tube. 



Agar-agar. — Grows rapidly, forming a shining smooth expansion. 



Potatoes. — Produces a thick, flesh-coloured, moist expansion. 



Broth. — Renders it turbid; an abundant sediment collects, and after a few 

 days a pellicle forms on the surface. 



B^marks. — Powerfully reduces the nitrates to nitrites. (See p. 27.) 



