418 MICRO-ORGANISMS IX WATER 



BACILLUS VEKMICULAEIS 



| LIQUEFIES GELATINE | 



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

 organismen im Wasser und im Boden,' Zeitschrift /. Hygiene, vol. vi., 1889, 

 p. 384. 



"Where Found. In water from the Eiver Lea near Chingford. An organism 

 obtained from water and subsequently described as B. vermiculosus by Zimmer- 

 mann (loc. cit., 1890) is doubtless identical with this. 



Microscopic Appearance. Large bacillus with rounded ends, in length 

 about 2 to 3 ^ long and about 1 /u broad. Forms extensive vermiform threads. 

 Produces oval spores about 1'5 /* long and 1 /* broad. It is not motile. 



Cultures. 



GELATINE PLATES. The colonies in the depth are irregular in contour. 

 This irregularity increases as the liquefaction commences, and the colony 

 approaches the surface. The periphery is seen to consist of closely-packed 

 wavy bands of bacilli, whilst the centre of the colony looks irregular and 

 wrinkled. 



GELATINE TUBES. Forms a moist shining grey expansion, whilst in the 

 depth the path of the needle is indicated by a slight sword-like growth. Slow 

 liquefaction of the gelatine takes place. 



AGAR-AGAK. Produces a smooth shining greyish expansion which only 

 extends slowly. 



POTATOES. Produces a thick irregular flesh-coloured pigment. 



Eemarks. Powerfully reduces the nitrate to nitrite. (See p. 27-) 



BACILLUS MEGATEKIUM 



LIQUEFIES GELATINE 



Authority. De Bary, Vcrgleichende Morphologic, und Biologic tier Pilze. 



Where Found. Isolated originally from cooked cabbage-leaves. Found in 

 water by Tils, Zeitschrift flir Hygiene, vol. ix., 1890, p. 312. 



Microscopic Appearance. Large slightly curved bacillus with rounded 

 ends, 2-5 p broad and 8 to 9 /* long. Characteristic granulation of the contents of 

 the cell is visible. It has a great tendency to produce involution forms. It 

 is motile, the movements being creeping. Forms spores at the end of the 

 rod. 



Cultures. 



GELATINE PLATES. Small round liquefying centres. 



GELATINE TUBES. Grows principally on the surface and liquefies the 

 gelatine. 



AGAR-AGAB. Produces a whitish expansion, whilst the agar becomes dark 

 coloured. 



POTATOES. Yellow white cheese-like growth, restricted to the point of 

 inoculation. 



