THE CLASSIFICATION OF BACTERIA 99 



65. M. aureus Dyar 



M. cremoides-aureus, Dyar : I.e. 



Morphology. Cocci i .0-1 .2 /i ; associated irregularly. 



Gelatin colonies. Deep: round, light yellow, opaque. Surface: cups of lique- 

 fied gelatin are quickly formed, and masses of opaque orange flocculi form 

 a ring about a clear central nucleus. 



Gelatin stab. A liquefaction along the line of stab. 



Milk. Coagulated, becoming peptonized. 



Pepton-rosolic acid solution. Unchanged. 



Lactose litmus. Reddened. 



Agar slant. Growth limited, glistening, orange. 



Glycerine agar. Growth scarcely chromogenic. 



Nitrates. Not reduced. 



According to Dyar, a variety of M. cremoides Zim., No. 54. 



Habitat. Air. 



66. M. flavus Fliigge 



M. fiavus-liquefaciens Fliigge: Die Mikroorganismen, i886. 



Morphology. Cocci rather large, in twos, threes, and in groups. 



Gelatin colonies. Deep: round, oval, often lobular. Surface: yellowish brown, 

 finely serrate, becoming surrounded by a zone of liquefied gelatin, con- 

 taining the central colony with isolated radial processes from the latter ; 

 colonies 4-6 mm. 



Gelatin stab. Growth in depth beaded, yellowish ; gelatin rapidly liquefied 

 with a yellowish flocculent sediment. 



Potato. Growth irregular, intense yellow. 



Habitat. From the air and water. 



67. M. luteus Cohn 



Beitrage Biologie, I, 1870. 



Morphology. Cocci i .0-1 .2 ju,, round, in twos and fours ; form zoogloea. Grow 

 at 37° C. 



Gelatin colonies. Deep : round-elliptical, entire, granular, yellowish gray. 

 Surface: yellowish — yellowish white, raised, round-irregular. In 3 days 

 1-2 mm., becoming sunken. Microscopically, yellowish gray — gray- 

 brown ; border undulate — lobed. 



Gelatin stab. Growth in depth beaded, becoming slowly liquefied, cylindrical. 

 (According to Frankland, gelatin not Hquefied.) 



Agar slant. Growth citron-yellow. 



