440 MICRO-ORGANISMS IN WATER 



BACILLUS EUBIDUS 



, LIQUEFIES GELATINE 



Authority. Eisenberg, Bakteriologische Diagnostik, 18 ( ,)1, p. 88. 



Where Found. In water. 



Microscopic Appearance. Medium-sized bacilli with rounded ends, often 

 forming long threads. It is very motile. 



Cultures. 



GELATINE PLATES. Bound finely granular liquefying colonies, with a 

 smooth rim and coloured centre. 



GELATINE TUBES. Liquefies the gelatine, slowly producing a brownish red 

 pigment. 



AGAR-AGAR. Forms a rapidly spreading brownish red expansion. 



POTATOES. Produces a fine brownish red-coloured growth, which is not 

 restricted to the point of inoculation. 



BLOOD SEBUM. Liquefies the serum, producing a red pigment. 



Remarks. It will not grow at higher temperatures. 



BACILLUS PBODIGIOSUS 



| LIQUEFIES GELATINE 



Authority. Ehrenberg. See also ' Ueber einige durch Bakterien gebildete 

 I'igmente,' Schroeter, Beitrcige zur Biologie der Pflanzen, Heft ii., 2nd 

 edition, Breslau, 1881, p. 109. See also, ' Studies on some new Microorganisms 

 obtained from Air,' Percy and G. C. Frankland, Phil. Trans., vol. clxxviii., 1887, 

 p. 284. 



"Where Found. On moist bread, potatoes, etc. Found in water by Tils 

 (loc. cit.) and Percy Frankland (loc. cit.). 



Microscopic Appearance. The cells are rather longer than broad, the 

 largest forms being about 1'7 /* in length and about 1 p. in width ; they are 

 frequently found hanging together in pairs. It is not motile. (See Plate I. ID.) 



Cultures. 



GELATINE PLATES. After two days the colonies are visible to the naked eye 

 us circular depressions, each having a red centre. Under a low power the less 

 developed colonies in the depth are devoid of red colour, are finely granular, 

 and have a very irregular contour. The surface colonies, on the other hand, 

 have a distinctly red nucleus, surrounded by a very thin and finely granular 

 brownish growth, having a very irregular contour. (Percy Frankland.) (See 

 Plate I. IK., Ic.) 



(ii;r.\n\i; Ti ;i;>;s. Grows very rapidly, liquefying the gelatine in the form 

 of a conical sack, which soon extends across the tube at the top, and, gradually 

 passing downwards, involves the whole tube. The liquid is very turbid, with 

 an abundant flocculent deposit of an intensely crimson colour. Near the surf ace 

 there is generally seen adhering to the glass a thin layer of still darker red- 

 colouring matter, which has the peculiar rluorescence of an aniline colour when 

 in a concentrated state. (Percy Frankland.) (See Plate I. IA.) 



AGAR-AGAR. Grows very rapidly, producing a deep, blood-red, smooth and 

 shining expansion, the colour being restricted to the surface. 



BLOOD SERUM. As on agar, only the serum becomes liquefied , 



POTATOES. - Grows luxuriantly, producing a magnificent red pigment, which 

 has a metallic brilliancy upon it. 



BROTH. Renders the broth turbid, and produces at first a white deposit, 

 which later becomes pinkish. 



Remarks. By long-continued culture it often loses its power of pigment-produc- 

 tion, which may gt-m-rally be restored by cultivation 011 potatoes. 



