404 MICRO-ORGANISMS IN WATER 



VIBKIO SAPKOPHILES a 



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

 Bakteriologie, vol. ii., 1887, p. 469. 



Where Found. In putrid hay infusion, also in sewer mud. 



Microscopic Appearance. Forms bent rods about 3 u. long ; in the middle 

 the width is about one-fifth that of the length, for it frequently becomes narrower 

 at the ends. Frequently 'S' forms are seen, but it rarely forms long filaments. In 

 broth and agar-agar cultures about eight days old delicate spiral forms are 

 found. It is very motile. 



Cultures. 



GELATINE PLATES. Grows slowly. Under a low power in transmitted light 

 the depth colonies are smooth-rimmed, yellowish-brown, circular discs; the 

 centre is dark, surrounded by concentric rings. Later the rim becomes serrated. 

 The surface colonies are flat yellowish-white expansions ; under a low power 

 they are not circular, and exhibit a sharply denned dark centre, whilst towards 

 the periphery the yellowish-grey colour becomes paler ; the contents are finely 

 granular. No liquefaction takes place. 



GELATINE TUBES. Forms a veil-like streak in the depth and a whitish ex- 

 pansion on the surface ; the gelatine which is not occupied by the growth looks 

 as if it had been covered by a transparent whitish cloud. 



AGAR-AGAR. Does not grow in the depth, but forms an abundant dirty 

 yellowish-white spreading expansion, beneath which the agar-agar is clouded 

 for a distance of 1 to 2 mm. 



POTATOES. Forms in two days an abundant slimy pasty growth, yellowish- 

 red in colour, which becomes darker until it is a full chocolate-brown. 



BROTH. Benders the liquid turbid, and produces a yellowish crumbly deposit, 

 in which wavy twisted threads are found. 



Remarks. It retains its vitality over a considerable period in agar-agar cultures, 

 a nine months old cultivation yielding growths on being re-inoculated (Weibel, Cen- 

 tralblatt f. Bakteriologie, vol. iv., 1888, p. 230). 



VIBKIO SAPEOPH1LES 7 



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

 Bakteriologie, vol. iv., 1888, p. 231. 



Where Found. In sewer mud. 



Microscopic Appearance. Resembles the V. sapropliiles a, but is about 

 twice as large. It rarely forms long twisted threads. It has a great tendency 

 to produce involution forms. It is not coloured by Gram's method. 



Cultures. 



GELATINE PLATES. The depth colonies are white and under a low power 

 they are ovoid, smooth-rimmed and granular. The centre is orange-coloured and 

 sharply defined, and surrounded by a light yellow zone. The colour becomes 

 darker with age. The surface colonies are flat, dirty white, somewhat opalescent 

 expansions, with a prominent white centre. Under a low power they resemble to 

 a certain extent the B. coli-communis. The edge is irregular and lobular ; the 

 zone nearest the periphery is pure white, penetrated by numerous very fine ovoid 

 furrows, upon which follows a light yellow ochre zone, which is streaked with 

 darker washed out spotted stripes. The centre is yellowish brown, containing 

 also delicate dark wavy lines. Later the peripheral zone becomes yellowish, and 

 the remaining zones decidedly darker. No liquefaction takes place. 



GELATINE TUBES. Forms a streak in the depth and a moderate-sized whitish 

 expansion on the surface. 



AGAR-AGAR. No development in the depth, but forms a dirty-white pasty 

 expansion covering the whole surface. 



POTATOES. Very inconstant in its growth, being sometimes a dark brown 

 growth, very dry and tough, resembling a mould, and at others yellowish brown, 

 moist and shining, often also mahogany brown in colour. 



BROTH. Benders it turbid and produces a thick firm pellicle, which sinks to 

 the bottom when shaken, but forms again later. 



