478 MICRO-ORGANISMS IN WATER 



EACILLUS LACTIS CYANOGENUS ( ' Bacillus der blauen 



Milch ' ) 



Auth.ority. — Hueppe, * Untersuchungen iiber die 2ersetzungen der Milch 

 ■durch Mikroorganismen,' Mittheilungen a. d, kaiserlichen Gesundheitsamte^ 

 -vol. ii., 1884, p, 355. Also Neelsen, * Studien iiber blaue Milch,' Cohn's 

 Beitrdge zur Biologie der Pflanzen, vol. iii., Heft 2, 1880, p. 187. 



Where Found. — In blue milk. Found frequently in Lawrence sewage by 

 Jordan (loc. cit.). 



Microscopic Appearance. — Bacilli about 1 to 4 /^ long and 0-3 to 0-5 /a 

 broad, with slightly blunted corners. It is very motile. Forms spores at the 

 end of the rod. 



Cultures. — 



Gelatine Plates.— Forms finely granular dirty white circular colonies, with 

 a smooth rim. After a time the gelatine in the vicinity becomes slightly 

 darkened. No liquefaction takes place. 



Gelatine Tubes.— Forms a nail-head growth, milk-white in colour ; the 

 surrounding gelatine becomes a diffused greyish blue colour, which later turns 

 darker and almost black. 



Agab-agak. — Forms a greyish expansion, the agar becoming dark brown in 

 ■colour. 



Potatoes. — Forms a restricted yellowish growth, whilst the whole potato 

 assumes a diffused greyish blue tone. 



Blood Sebum. — Grows, but does not produce any pigment. 



Bemarks. — On being introduced into raw milk it produces grey blue or sky-blue 

 spots of colour. The colour is most pronounced on the surface. Sterilised milk, 

 when inoculated with the bacillus, does not become so intensely sky-blue in colour as 

 raw milk ; it is never coagulated, neither does it become acid ; but, on the contrary, it 

 -turns gradually slightly alkaline and remains fluid, (Hueppe, loc. cit., p. B58.} 



BACILLUS BUTYEICUS 



I LIQUEFIES GELATINE | 



Authority.— Hueppe, * Untersuchungen iiber die Zersetzungen der Milch 

 ■durch Mikroorganismen,' Mittheilungen a. d. kais. Gesundheitsamte, vol. ii., 

 1884, p. 309. 



Where Found. — In milk ; also in water by various investigators. 



Microscopic Appearance. — More or less long bacilli, sometimes bent ; also 

 forms threads. Mean dimensions, 2*1 n long and 0-38 f^ broad. It is very 

 motile. Forms at about 30° C. shining egg-shaped spores in the middle of 

 the rod. 



Cultures. — 



Gelatine Plates. — Forms in the depth small yellow aggregates, which 

 rapidly liquefy the gelatine, the colonies running together and forming a 

 granular brown mass. Further observation of the colonies is impossible. 



Gelatine Tubes. — Rapidly liquefies the gelatine, produces a yellowish colour, 

 and a thin, delicately folded looking pellicle, grey white in colour, forms on the 

 surface ; the liquid portion becomes cloudy and opaque. 



Agar-agar. — Forms a slight and dirty yellow expansion. 



Potatoes. — Produces a fawn-coloured transparent growth, which later 

 hecomes clouded, and sometimes exhibits tiny folds (Loeffler). 



Eemarks. — It grows best between 35° and 40^^ C, less well at 30° C. Produces a 

 hitter taste in milk and its coagulation. 



