BACILLI 449 



BACILLUS FLUORESCENS AUREUS 



Authority. Zimmermann, Die Bakterien unsercr Trink- und Nutzwasser, 

 insbcsondere des Wassers der Chemnitzer Wasscrleitung, Chemnitz, 1890. 



Where Found. In the Chemnitz water supply. 



Microscopic Appearance. Short bacillus about 0-74 M broad, and about twice 

 as long, with rounded ends ; occurs in pairs, rarely in greater numbers ; the 

 individuals lie together in larger and smaller groups. It is very motile, and has 

 cilia attached. No spore formation observed. 



Cultures. 



GELATINE PLATES In the depth, small yellowish white dots ; on the surface, 

 yellowish grey, moist and shining expansions. Under a low power the depth 

 colonies are sharply denned, pale yellow, granular and smooth-rimmed discs ; 

 the surface colonies are irregular in contour, denser in the centre and delicately 

 streaked. 



GELATINE TUBES. Forms a thin yellowish expansion, which later becomes 

 thicker, and reaches after from eight to ten days the edge of the glass. It only 

 grows very scantily in the depth, and assumes a somewhat brownish appear- 

 ance. When streaked on sloped gelatine it produces a thickish ochre yellow 

 expansion, beneath which the gelatine becomes strongly brown in colour, and 

 becomes fluorescent. No liquefaction takes place. 



AGAR-AGAR. Produces an abundant ochre or gold-yellow extensive expansion, 

 whilst the agar becomes darker in colour, but does not fluoresce. 



POTATOES. Similar growth as on agar-agar, but less plentiful. 



BACILLUS AURANTIACUS 



Authority. Percy and G. C. Frankland, Zeitschrift fur Hygiene, vol. vi. 

 p. 390. 



Where Found. In the deep well-water obtained from the chalk by the 

 Kent Company. 



Microscopic Appearance. Short fat bacillus of very variable dimensions. 

 It grows in pairs and also forms long threads. The short bacilli are nearly 

 !? fj. long, and nearly half as wide as long. No spores were observed. The 

 individual bacilli are motile. 



Cultures. 



GELATINE PLATES. Produces bright orange pin-heads. Under the micro- 

 scope the depth colonies are seen to be smooth-rimmed. No liquefaction of the 

 gelatine takes place, and its growth is slow. 



GELATINE TUBES. A shining orange-coloured expansion forms on the sur- 

 face, whilst hardly any growth is visible in the depth. 



AGAR-AGAR. Forms a bright orange expansion, which does not extend much 

 beyond the point of inoculation. 



BROTH. The liquid remains clear, whilst a slightly orange-coloured deposit 

 is produced. A thin pellicle forms on the surface, which exhibits here and 

 there bright spots of orange colour. 



POTATOES. Produces a thick and magnificent brilliant red orange pigment, 

 which is, however, restricted to the point of inoculation. 



Remarks. Reduces the nitrate to nitrite only very slightly when introduced into 

 the nitrate solution. (See p. 27.) 



G G 



