460 MICRO-ORGANISMS IN WATER 



BACILLUS NUBILUS 



I LIQUEFIES GELATINE 



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

 organismen im Wasser u. im Boden,' Zcitschrift f. Hygiene, vol. vi., 1889, 

 p. 386. 



Where Found. In filtered river Thames water. Found also by Tils (loc. 

 cit.) in Freiburg water, also probably by Tataroff (loc. cit.) in Dorpat water. 

 This author considers the Jlacilliix nubilns to be identical with the Bacillus 

 gracilis subsequently described by Zimmermann (loc. cit.). 



Microscopic Appearance. Slender bacillus, about 3/* long and 0-3 p. broad. 

 Forms long wavy threads in broth cultures. The isolated bacilli exhibit 

 violent rotatory movements, but the threads are quite stationary. No spores 

 observed. 



Cultures. 



GELATINE PLATES. Forms cloudy undefined patches, which under the 

 microscope are seen to consist of a thick and tangled mass of bacillar threads. 

 Rapid liquefaction of the gelatine takes place. 



GELATINE TTMES. The surface is liquefied, but all along the path of the 

 needle a series of horizontal circular plates arise, having a delicate cloud-like 

 appearance. Later the whole contents of the tube become fluid. 



ACAR-AGAR. Produces a thin opalescent blue violet expansion, the edges of 

 which exhibit later a distinct violet fluorescence. 



POTATOES. Forms a delicate and slightly yellow growth, which is barely 

 visible. 



KKOTH. 1 lenders it turbid and produces a dirty white deposit, whilst the 

 surface becomes covered with a thin pellicle. 



Remarks, Ileducos a very small proportion of the nitrate to nitrite. (See n. 27. \ 



BACILLUS LIODEBMOS (Fliigge) 



LIQUEFIES GELATINE | 



Authority. Fliigge, l>i<' Mikroorganismen, issii, p. 333. 



Where Found. Found in water by Adumetz (loc. cit.). A liacillux 

 liodermos (Qummibacillus) lias been isolated by Loefrler from milk (Berliner 

 klin. Wochenschriftt 1887, p. (JHO), but it is uncertain whether it is' the same as 

 Fliigge 's. 



Microscopic Appearance. Small, short bacillus with rounded ends. It is 

 very motile. 



Cultures. 



GELATINE PLATES. Forms irregularly shaped centres, which float like a small 

 white skin on the surface of the rapidly liquefied gelatine. 



GELATINE TUBES. Kapidly liquefies the superficial layers of the gelatine, and 

 greyish yellow flocculent particles collect, whilst lower down the needle's path 

 exhibits a grey growth. 



POTATOES. Forms a smooth shining expansion which rapidly extends over 

 the whole surface, giving it the appearance of having been covered with a 

 yellowish white syrup. After some days the smooth surface becomes cloudy 

 and slightly wrinkled, but it never produces very deep furrows like the Jl. 

 mesentericus rnlga / u s. 



