MICROCOCCI 501 



MICROCOCCUS AUEANTIACUS 



Authority. — Schroeter, Beitrdge z. Biologie der Pfiansen, vol. i., Heft ii., 

 1870, p. 119 ; also Cohn, loc. cit., p. 154. See also Die Bakterien derNutz- und 

 Trinkwasser, by Adametz, Vienna, 1888. 



"Where Found. — In air and water. 



Microscopic Appearance. — Bound or slightly oval cocci, having a diameter 

 of from 1-3 to 1-6 fi. They occur singly or as diplococci, or gathered together 

 in small heaps. Not motile. 



Cultures. — 



Gelatine Plates.^ — Forms round or elliptical orange yellow centres, with a 

 smooth, shining surface. Under a low power they are seen to be finely granular. 

 No hquef action ensues. 



Gelatine Tubes.— Grows chiefly on the surface in the form of small yellow 

 pin-heads, whilst in the depth along the needle's path small orange yeUowdots 

 very slowly make their appearance. 



Agar-agar. — Forms an orange yellow expansion. 



Potatoes. — Produces a slimy, yellow growth. 



Remarks. — The orange yellow pigment is insoluble in water, alcohol, and ether. 



MICEOCOCCUS FLAVUS LIQUEFACIENS 



LIQUEFIES GELATINE 



Authority. — Fliigge, Die Mikroorganismen, 1886, p. 174. 



"Where Found. — In air and water. 



Microscopic Appearance. — Eather large cocci, occurs mostly in twos or 

 threes, or in groups. Not motile. 



Cultures. — 



Gelatine Plates. — After two days small yellowish centres are visible, 

 surrounded by a flat circular depression. Under a low power the depth colonies 

 are circular or oval, and have also sometimes a lobular projection at one 

 point. The surface colonies are sharply defined and finely serrated, and are 

 of a yellowish brown colour ; when liquefaction has commenced the periphery 

 forms a sharp circular liquid ring, which is broken through in places by isolated 

 aggregates of cocci, so that later the neighbouring colonies become mixed up 

 with one another. The yellow centre of the colony is surrounded by a broad 

 clear liquid zone, in which isolated radial extensions from the centre are 

 visible. At this stage the colony resembles a carriage -wheel. 



Gelatine Tubes.— All along the needle's path in the depth small round 

 yellow colonies appear, which rapidly liquefy the gelatine, so that in eight days 

 the test-tube contains in the upper layers clear hquid, and at the bottom a 

 yellow fiocculent deposit. 



Potatoes.— Produces an irregular, intensely yellow expansion. 



