470 MICRO-ORGANISMS IN WATER 



BACILLUS PULVUS 



LIQUEFIES GELATINE 



Authority. — Zimmermann, Die Bakterien unserer Trink-und Nutzwassevy 

 inshesmidere des Wassers der Chemnitzer Wasserleitung, Chemnitz, 1890. 



"Where Found.— In the Chemnitz water supply. 



Microscopic Appearance. — Short bacilli with rounded ends, about 0*86 ta 

 1*3 fi long and about 0-77 /* broad, consisting of one or more individuals. No 

 spore formation observed. It is not motile. 



Cultures.— 



Gelatine Plates. — In the depth the colonies are irregularly rounded or egg- 

 shaped, yellowish grey and granular. The surface colonies are of a reddish yellow 

 colour, and after eight days have extended for a distance of 1 mm. or more ; 

 they resemble raised round drops. 



Gelatine Tubes. — Produces an irregular raised circular growth resembling 

 the colour of gamboges^ The path of the needle is clearly marked and of a. 

 slightly yellow colour. Liquefaction takes place after some weeks. 



Agab-agab. — Forms an abundant shining yellowish expansion. 



Potatoes. — Develops slowly and produces an Indian-yellow coloured growth,, 

 which later is nearly ochre yello^w. 



Eemarks. — It growa most rapidly at '60° C. 



BACILLUS PILIFOEMIS 



LIQUEFIES GELATINE 



Authority. — Tils, ' Bakteriologische Untersuchung der Freiburger Leitungs- 

 wasser,' Zeitschrift f. Hygiene, vol. ix., 1890, p. 317. 



"Where Found. —Found in the Freiburg water supply during the autumn 

 months. Eoux (Precis d* Analyse microhiologiqite des Eaux, 1891, p. 315) say& 

 that he isolated from the river Saone at Lyons a bacillus which had a striking 

 resemblance to Tils' form, and which he has called provisionally Strepto- 

 bacille. 



Microscopic Appearance. — Bacillus 4 /a long and about 1 /x broad ; occurs 

 usually hanging together, forming filaments consisting of as many as eight 

 individual bacilli, the divisions being almost undistinguishable. The isolated 

 bacilli, and those in twos or threes, have an oscillatory movement, whilst the 

 long threads are motionless. Shining spores appear in the middle of the rod. 



Cultures. — 



Gelatine Plates. — The depth colonies are whitish, finely granular, with an 

 irregular edge. The surface colonies form at the end of three days whitish 

 expansions having a striped appearance. Under a low power the periphery is 

 irregular and serrated, and consists of closely-packed wavy bundles of bacilli ;. 

 the centre looks uneven and granular. The edge of the colony is colourless, 

 but towards the middle it becomes yellowish. Slow liquefaction of the gelatine, 

 takes place after several days. 



Gelatine Tubes.— Grows scantily in the depth, but produces a moist ex- 

 pansion on the surface, with a wavy serrated edge. Liquefaction commences 

 after a few days, and thick flocculent masses sink to the bottom. Below the 

 line of liquefaction the still solid gelatine looks very clouded. 



Agab-agar. — Grows rapidly, producing a more pronounced wavy-looking, 

 growth than on gelatine. 



Potatoes. — Forms a thick irregular dirty white expansion, which later be- 

 comes darker and discoloured. 



