478 MICRO-ORGANISMS IN WATER 



BACILLUS LACTIS CYANOGENUS (' Bacillus der blauen 



Milch ' ) 



Authority. Hueppe, Untersuchungen iiber die Zersetzungen der Milch 

 'durch Mikroorganismen,' Mittheilungen a. d. kaiserlichen Gesundhettsamte, 

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

 Beitrage 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 ju long and 0-3 to 0-5 /t 

 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. 



AGAR-AGAR. 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 SERUM. Grows, but does not produce any pigment. 



Remarks. 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. 858.) 



BACILLUS BUTYKICUS 



LIQUEFIES GELATINE | 



Authority. Hueppe, ' Untersuchungen iiber die Zersetzungen der Milch 

 durch Mikroorganismen,' Mittheilungen a. d. kais. Gesundheitsainte, 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 /JL long and O38 p 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 

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



Remarks. It grows best between 35 and 40 C., less well at 30 C. Produces a 

 bitter taste in milk and its coagulation. 



