500 MICRO-ORGAN ISMS IN WATER 



MICKOCOCCUS CEEMOIDES 



| LIQUEFIES GELATINE_j 



Authority. Zimmermann, Die Bakterien unserer Nutz- und Trinkwasser, 

 insbesondere des Wassers der Chemnitzer Wasserleitung, Chemnitz, 1890. 



"Where Found. In the Chemnitz water supply. 



Microscopic Appearance. Cocci about 0-8 p. in diameter, grouped together 

 like a bunch of grapes. Not motile. 



Cultures. 



GELATINE PLATES. In the depth small yellowish white dots are visible. Under 

 a low power they are circular discs, smooth-rimmed, and with yellowish or 

 greyish brown granular contents. On reaching the surface the contour becomes 

 lobular and denticulated, and the gelatine becomes liquid in a saucer-like depres- 

 sion. The yellowish white colony covers the bottom of the depression, and 

 becomes arranged in concentric rings. Under a low power such colonies con- 

 sist of brownish yellow granular aggregates, surrounded by a less dense granu- 

 lar circle, which is enclosed by a transparent liquid zone in which granular 

 particles are scattered here and there. From the periphery delicate and 

 radial extensions often stretch into the adjacent gelatine. 



GELATINE TUBES. In from three to four days the path of the needle in the 

 depth is liquefied, whilst on the surface a bubble of gas is usually present, 

 beneath which yellowish white masses of bacterial growth collect, and lower 

 down the liquid is clear or contains but a few granular particles, whilst the bot- 

 tom of the funnel again is filled with the yellowish white growths. After 

 from six to seven days a yellowish white pellicle floats on the surface of the 

 liquid gelatine. 



AGAR-AOAR. Forms a yellowish white amber-like shining expansion, which 

 is irregular and lobular at the periphery, and granulated on the surface. 



POTATOES. Grows abundantly, producing a raised cream-coloured expansion. 



Remarks. It will not grow in the absence <jf oxygen. 



MICROCOCCUS FERVIDOSUS 



Authority. Adametz, Die Bakterien der Nutz- und Trinkiccisser, Vienna, 

 1888. 



Where Found. In water. 



Microscopic Appearance. Small round cocci 0-6 ^ in diameter; occurs as 

 diplococci, also in small groups. Not motile. 



Cultures. 



GELATINE PLATES. The depth colonies appear as small white dots after from 

 four to five days. Under a low power they are faint yellow in colour, highly re- 

 fracting, smooth-rimmed, and resemble drops of dew. The surface colonies, after 

 from five to six days, are transparent and yellow, with a serrated edge and nume- 

 rous indentations and lobular projections. In older colonies the centre is granular 

 and brownish in colour, whilst the yellowish growth surrounding it exhibits a 

 slight folded appearance. No liquefaction takes place. 



GELATINE TUBES. Forms a very thin surface expansion, circular, and finely 

 serrated, whilst a granular growth appears in the depth. 



GLYCERINE-GELATINE. Gives rise to numerous bubbles of gas all along the 

 needle's path in the depth. 



AGAR-AGAR. Forms a circular milk-white slimy expansion which exhibits 

 later a mother-of -pearl iridescence. 



POTATOES. Produces a dirty white irregular expansion. 



Remarks. In cane, grape, and milk-sugar solutions respectively it develops 

 slowly, causing a slight turbidity (Tils). 



