460 MICRO-ORGANISMS IN WATER 



BACILLUS NUBILUS 



LIQUEFIES GELATINE 



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

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

 p. 386. 



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

 cit.) in Fr'eiburg water, also probably by Tatarott" {loc. cit.) in Dorpat water. 

 This author considers the Bacilhis nubilus to be identical with the Bacilkis 

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



Microscopic Appearance.— Slender bacillus, about 3^ long and 0*3 fi broad. 

 Forms long wavy threads in broth cultures. Th§ 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 Tubes. — 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. 



ActAH-agar. — Produces a thin opalescent blue violet expansion, the edges of 

 which exhibit later a distinct violet fluorescence. 



Potatoes. — Forms a delica.e and slightly yellow growth, which is barely 

 visible. 



Broth. — IHenders it turbid and produces a dirty white deposit, whilst the 

 surface becomes covered with a thin pellicle. 



Kemarks. — Reduces a very small proportion of the nitrate to nitrite. {See p. 27.) 



BACILLUS LIODEEMOS (Flugge) 



! LIQUEFIES GELATINE 



Authority. — Fliigge, Die 2Jikroorganis?nen, 1886, p. 323. 



Where Found. — Found in water by Adametz [loc. cit.). A Bacilhis 

 liode7'7nos (Gitmmihacilhis) has been isolated by Loefiier from milk (Berliner 

 Mill. Wochenschrift, 1887, p. 630), but it is uncertain whether it is the same as 

 Fiiigge'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. — Eapidly 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 B. 

 mesenteric us vulgattts. 



