424 MICRO-ORGANISMS IN WATER 



BACILLUS PYOCYANKUS Gessf 



I LIQUEFIES GELATINE j 



Authority. Gessard, De la Pyocyanine et de son Microbe, Th&se de 

 Paris, 1882 ; also Charrin, Communication faite a la Societe anatomique, 

 December 1884 ; Ernst, ' Ueber einen neuen Bacillus des blauen Eiters,' 

 Zeitschrift /. Hygiene, vol. ii., 1887, p. 369. This author has found a variety of 

 the B. pyocyaneus previously described which produces a bluish green colour, 

 rapidly liquefies the gelatine, and gives rise to very little fluorescence. 



Where Found. In green pus. Found by Tils (Zoc. cit.) in the Freiburg 

 water. 



Microscopic Appearance. Small slender bacillus, about as long as the 

 bacillus of mouse septicaemia, but slightly broader. It occurs singly, but also in 

 irregular groups. It forms spores (Fliigge). It is very motile, and has one 

 cilium attached to each bacillus (Loeffler). 



Cultures. 



GELATINE PLATES. Forms irregular flat expansions, in the vicinity of which 

 the gelatine is rapidly liquefied and assumes a green fluorescence. The depth 

 colonies are circular and the highly refracting rim is light and granular. 



GELATINE TUBES. Forms in twenty-four hours a funnel-shaped liquid 

 depression, whilst in the superficial layers the gelatine is fluorescent, and later 

 the whole contents of the tube become beautifully green fluorescent. 



AGAR-AGAR. Forms a moist greenish white expansion, and the whole of the 

 agar becomes green fluorescent. 



POTATOES. Produces a red brown expansion confined to the point of inocula- 

 tion. When the potato is treated with ammonia the growth becomes green, 

 and when treated with an acid red, in colour. 



Remarks. Injected into the peritoneum of guinea-pigs, the latter die (Koch). 

 Injected intravenously into rabbits, they do not die. The bacillus appears to increase 

 in virulence when continually inoculated from one animal into another. For the 

 effect of insolation 011 this bacillus, see p. :i.">:J. 



BACILLUS FLUOEESCENS TENUIS 



Authority. Zimmermann, Die Bakterien unscrcr Tririk- und Nutzicasser, 

 insbes. des Wassers der Cliemnitzcr Wasserlcitiing, Chemnitz, 1891. 



Where Found. In the Chemnitz water supply. 



Microscopic Appearance. Short thick bacillus about 0-8 /u broad, and 1-0 to 

 1-85 M long, with rounded ends, except in very young rods, when only one end is 

 rounded. It occurs in groups, and in older cultures the rods consist of four to 

 six individual bacilli. It is decolourised by Gram's method, which distinguishes 

 it from B. fluoresccns longus. Is capable only of oscillatory and rotatory move- 

 ments. The same uncertainty as regards spore formation as in the B.f. longus. 



Cultures. 



GELATINE PLATES. Forms thin shining, not always circular expansions, with 

 an irregular denticulated edge. The surrounding gelatine is coloured green 

 for some distance beyond the limit of the colony. 



GELATINE TUBES. Forms a grey white expansion, which after four days 

 reaches the wall of the tube. The needle's path in the depth is clearly defined, 

 but no further growth makes its appearance. The gelatine is coloured green. 

 When streaked on a sloped gelatine surface, it forms a most delicate leaf-like 

 expansion. No liquefaction takes place. 



AGAR-AGAR. Forms a grey, smooth, shining, but not abundant expansion. 

 The agar becomes gradually green. 



POTATOES. At first restricted to the path of inoculation, and appears as a 

 thin greyish yellow shining expansion, which later becomes red brown in 

 colour. 



