406 MICRO-ORGANISMS IN WATER 



VIBRIO FLAVESCENS 



Authority. Weibel, ' Untersuchungen iiber Vibrionen,' Ccntralblatt f. 

 Bakteriologie, vol. iv., 1888, p. 260. 



"Where Found. In sewer mud. 



Microscopic Appearance. Resembles Vibrio aureus. 



Cultures. 



GELATINE PLATES -The shape of the colonies resembles Vibrio aureus ; on 



a dark ground the colour is dirty greyish yellow, on a light ground dirty 

 greenish yellow, forming a ready mark of distinction between the colonies of 

 Vibrio aureus and Vibrio flavus. Under a low power the colonies resemble 

 Vibrio aureus, but the shade of yellow is lighter, feebler, and less pure. No 

 liquefaction ensues. 



GELATINE TUBES Resembles Vibrio aureus, the expansion being, however, 

 instead of bowl-shaped, Hatter, with a lobular edge. 



AGAR-AGAR. Resembles Vibrio aureus, the colour being, however, dull 

 yellow, with isolated grey-coloured spots. 



POTATOES. Resembles Vibrio aureus, the colour being, however, dull 

 yellow. 



BROTH. Resembles Vibrio aureus. 



SPIRILLUM RUBRUM 



Authority. Esmarch, 'Ueberdie Reincultur ernes Spirillum,' Centralblatt 

 f. Bakteriologie, vol. i., 1887, p. 225. 



"Where Found. In water in which the body of a mouse dead of septicaemia 

 had been allowed to putrefy. Found by Adametz in water. 



Microscopic Appearance. Forms short spirilla with 1, 2, or 3 screw 

 twists in gelatine, agar-agar, and potatoes, but as many as 30, 40, and 50 in 

 broth cultures. It is about twice as thick as the Comma spirillum. The 

 shorter spirilla are very motile, the longer ones are either motionless or capable 

 of very slight motility. Shining spots are visible in the interior, which, al- 

 though refusing to stain like spores, are regarded as such. 



Cultures. 



GELATINE PLATES. Grows exceedingly slowly, eight days often elapsing 

 before any colony becomes visible to the naked eye. It forms grey or pale red 

 centres, with somewhat granular contents and a very nearly smooth rim ; 

 gradually the colour becomes wine-red, especially the deeper down the colonies 

 are in the depth. No liquefaction takes place. 



GELATINE TUBES. Grows the whole length of the needle track in the depth, 

 forming closely compressed round wine-red colonies, but on the surface and 

 near the surface, where air has access, it produces no coloured growth. 



AGAR-AGAR AND BLOOD SERUM. Forms a moist, shining, grey-white restricted 

 expansion, becoming wine-red in the thicker parts of the growth. The con- 

 densed water becomes filled with very long spirilla, and later a red sediment 

 collects. 



POTATOES. Grows very slowly, the deep red colonies never exceeding in 

 size that of a hemp-seed. 



BROTH. Forms a red sediment and renders the liquid slightly turbid. 



Remarks. Not pathogenic when subcutaneously introduced into mice, guinea- 

 pigs and rabbits. It is killed when exposed to 42 C. for twenty-four hours; grows 

 best at 37 C. 



