BACILLI 419 



BACILLUS EAMOSU S (Wu rzel bacillus) 



I LIQUEFIES ^ELATINE | 



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

 organismen im Wasser und im Boden,' Zeitschrift f. Hygiene^ vol. vi., 1889, p. 

 388. Doubtless identical with the Wursel haeillus (Eisenberg, Bakteriologisctie 

 Diagnostik, 1891, p. 126), and the Bacillus implexus described by Zimmermann 

 as occurring in the Chemnitz water. 



Where Found.— Originally in soil. Found by various investigators in water, 

 and by the authors frequently in the rivers Thames and Lea, but not in deep 

 well-water from the chalk. 



Microscopic Appearance.— Much resembles B. subtilis. The individual 

 bacilli are about 7 /i long and 1-7 fi broad, the ends being distinctly rounded. 

 It gives rise to long threads, also spores. Is capable of only slight oscillatory 

 movement. 



Cultures. — 



Gelatine Plates. — The colonies are seen to consist of cloudy centres with 

 tangled root-like branches extending in every direction. Later liquefaction of 

 the gelatine takes place. (See Plate II. 1a.) 



Gelatine Tubes. — On the second day already a slight depression is visible 

 on the surface, whilst the path of the needle in the depth has a grey woolly 

 appearance. The whole contents of the tube become subsequently impregnated 

 with fluffy ramifications and the gelatine becomes fluid, whilst a tough pellicle 

 forms on the surface. 



Agab-agab. — Grows rapidly over the whole surface, whilst in the depth the 

 characteristic ' branching ' is again visible. 



. Potatoes. — Produces a dry and uniform expansion which is almost quite 

 white. 



Broth. - Forms a light flocculent deposit, and produces later a tough and 

 wrinkled pellicle on the surface. 



Remarks. — It powerfully reduces the nitrate to nitrite. (See p. 27.) 



BACILLUS MYCOIDES 



LIQUEFIES GELATINE 



Authority.— Fliigge, Die Mikroorganismen, 1886, p. 324. 



Where Found.— Found very frequently in the superficial layers of arable 

 and garden soil. Also in water by Zimmermann, loc. cit., and by Eoux, loc. cit., 

 and in hail byFoutin, loc. cit. This organism resembles in many particulars the 

 B. ramosus, but evidence as to its actual identity with the latter is still wanting. 



Microscopic Appearance.— Bacillus from 1*6 to 2-4 ^ long, and about 0*9 /i 

 broad. It generally occurs in long threads, but the bacillar divisions of which 

 are easily seen in stained preparations. It forms very lustrous oval spores 

 about 1-3 to 1-48 /t long and 0-74 to 0-9 fi broad. It is motile. 



Cultures.— 



Gelatine Plates.— Forms a white, cloudy patch, in which later fine white 

 interwoven threads become visible, and the branching of which resembles a 

 mould. As soon as these thread-like growths reach the surface they expand, 

 and the gelatine is liquefied. 



Gelatine Tubes. — Rapid liquefaction of the upper layers of the gelatine, 

 whilst in the depth hair-like ramifications, much branched and interwoven, 

 extend from the needle's path into the gelatine. Later liquefaction extends 

 throughout the tube, and a pellicle forms on the surface. 



Agar-agae. — Fine mould-like ramifications extend on both sides of the 

 needle's path on the surface. 



Potatoes. — Forms in twenty-four hours a greyish white, slimy expansion, 

 which later covers the whole surface. 



Remarks. — In Wiedemann's ^Tina^e?^ der Physik u. Ghemie^ No. 8, 1893, Marchal 

 states that the B, inycoides exerts a double action in soil iu the production of 

 ammonia, liberating ammonia from nitrogenous organic matter, and also denitrifying 

 nitrates. See also action of B, ramosus on nitrates. 



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