102 BACTERIOLOGY 



Gelatin stab. Surface growth thin, glistening, yellowish ; in 3 weeks the 

 gelatin is liquefied to a depth of 6 mm. ; gelatin opaque, yellowish. 



Agar slant. Growth yellowish brown. 



Potato. Growth grayish yellow. 



Habitat. Isolated from the skin of persons suffering from eczema suborrhei- 

 cum. 



74. M. versatilis Sternberg 



M. tetragenus-versatilis Sternberg : Manual of Bacteriology, 1892. 



Morphology. Cocci 0.5-1.5 \x,\ in tetrads and irregular groups. Stain by 



Gram's method. 

 Gelatin colonies. Round, opaque, light yellow — lemon-yellow. Liquefaction 



begins after several days, and progresses slowly. 

 Gelatin stab. In depth, slight growth ; on surface, a crateriform liquefaction, 



vvith a yellowish viscid sediment. 

 Agar slant and potato. Growth thick, viscid, yellow, moist, glistening, 



spreading. 

 Pathogenesis. Rabbits and guinea pigs negative. 

 Habitat. Isolated from the excrement of mosquitoes which had sucked the 



blood of yellow fever patients, and from the air. 



74 a. M. tetragenus-vividus Dyar 



N. Y. Acad, of Sciences, VIII, 354. 

 Probably a variety of or identical with the preceding. 



CLASS VIII. DISTINCTLY CHROMOGENIC. PIGMENT YELLOWISH 

 ORANGE. GELATIN NOT LIQUEFIED 



I. Cocci in tetragenous groups. 



75. M. varians (Dyar). 



76. M. Vincenzii. 



II. Cocci in Staphlococcus groupings. 



A. Growth on potato yellowish. 



1. Pigment orange-yellow. 



77. M. aurantiacus (Schroter) Cohn. 



2. Pigment lemon-yellow. 



78. M. cereus Passet. 



3. Pigment brownish yellow. 



79. M. orbiculatus Wright. 



B. Growth on potato invisible. 



80. M. aerius. 



