MICROCOCCI 4 95 



MICKOCOCCUS VIOLACEUS 



Authority. Schroeter, ' Ueber einige durch Bacterien gebilclete Pigmente,' 

 Cohn's Bcitrage zur Bioloyie der Pflanzen, vol. i., Heft ii., p. 124. 



"Where Found. In air and water. 



Microscopic Appearance. Elliptically shaped cocci, larger than those of 

 B. prodigiosus, and arranged in chains. Not motile. 



Cultures. 



GELATINE PLATES. Forms slimy drop- like raised growths of a violet colour ; 

 the latter appear on the surface of the colony. No liquefaction ensues. 



POTATOES. Originally obtained from air by Schroeter on exposed slices of 

 potato, appearing as slimy spots of a strong violet blue colour, which gradually 

 coalesced and produced a flat violet-coloured expansion. (Schroeter, loc. cit.) 



MICKOCOCCUS CYANEUS 



Authority. Schroeter, ' Ueber einige durch Bacterien gebildete Pigmente,' 

 Beitrage z. Biologie der Pflanzen, vol. i.. Heft ii., 1870, p. 122 ; also Cohn, 

 ' Untersuchungen iiber Baoterien,' loc. cit., p. 15<>. 



"Where Found. In air by Schroeter. Included by Lustig amongst bacteria 

 found in water. 



Microscopic Appearance. Elliptical cocci. Not motile. Forms zooglosa. 



Cultures. 



GELATINE PLATES. Forms small, circular, well defined colonies. Under a 

 low power the centre is bluish in colour, and is surrounded by an irregular 

 network. 



GELATINE TUBES. It will not grow in the depth, but forms a slimy mass on 

 the surface. No liquefaction ensues. 



POTATOES. Develops slowly (about ten days), forming a dark indigo blue 

 growth which penetrates into the depth of the potato. When examined under 

 the microscope no bacteria were found in the depth. (Schroeter.) 



Remarks. The pigment resembles litmus in colour. 



MICBOCOCCUS CONCENTEICUS 



Authority.- Zimmermann, Die Bakterien unscrcr Trink- itnd Nufzwasser, 

 insbesondcre des Wassers der Chemnitzer Wasserleitung, Chemnitz, 1890. 



Where Found. In the Chemnitz water supply. 



Microscopic Appearance. Cocci 0-9 /j. in diameter, arranged in irregular 

 groups. Not motile. 



Cultures.- 



GELATINE PLATES. The depth colonies are small bluish grey dots. On the 

 surface it forms at first small bluish grey discs, which gradually become larger 

 and more irregular. After five days the centre is greyish white, arid is surrounded 

 by a bluish grey irregular and lobular periphery. Under a lo\v power the 

 depth colonies 'are light brownish or greenish yellow granular circular discs, 

 in the interior of which several almost regular, concentric circles are visible. 

 The surface colonies exhibit in the interior a greyish brown dark disc, with an 

 irregular and lobular edge, with fine radial serrations in places ; round this a 

 lighter brown granular ring, likewise with an irregular and lobuiar edge, is 

 visible ; the whole is enclosed by a whitish and shining border. No liquefaction 

 takes place. 



GELATINE TUBES. Forms a thin bluish grey or whitish expansion which 

 exhibits concentric circles, starting from the point of inoculation. 



AGAE-AOAH. -Produces a broad flat bluish grey white shining expansion, with 

 a serrated edge. 



POTATOES. Forms a thin yellowish grey smeary growth. 



