THE CLASSIFICATION OF BACTERIA 93 



51. M. descidens Flflgge 



Die Mikroorganismen, 1886. 



Morphology. Small cocci and diplococci, or in threes and short chains. 

 Gelatin colonies. Deep : 2 days, small, white-yellowish ; microscopically oval, 



yellowish brown, granular. Surface: 4 days, round-lobular, 5-10 mm., 



light yellowish-brownish smooth slimy expansions, not at all elevated; 



finally colonies sink in a flat circular depression. 

 Gelatin stab. In depth growth white, filiform ; on surface growth yellowish 



brown, slimy, becoming sunken. 

 Potato. Growth yellowish brown, thick, slimy. 

 Habitat. Air and water. 



52. M. alpha Foutin 



Coccus A Foutin : Centralblatt f. Bakteriologie, VII, 1890, 372. 



Morphology. Cocci round. Stain by Gram's method. 



Gelatin colonies. In 4 days, elevated white disks ; microscopically, darker in 



centre ; periphery lighter and slightly granular. 

 Gelatin stab. But scanty growth in depth ; on surface a yellowish nailhead ; 



liquefaction begins in 5-6 days, and proceeds slowly. 

 Agar slant. Growth light rose-colored, smooth, glistening. 

 Potato. Growth like B. typhosus. 

 Pathogenesis. Negative for mice and guinea pigs. 

 Habitat. Found in hail. 



53. M. tetragenus-pallidus Dyar 



L,c., p. 354. According to Dyar, a variety of M. tetragenus-vividus , No. 74. 



54. M. cremoides Zimmerman 



Bak. Nutz u. Trinkwasser, Chemnitz, 1890. 



Morphology. Cocci 0.8 /*, in clumps. 



Gelatin colonies. Deep ; round, entire, yellowish — grayish brown, granular. 

 Surface: lobular-denticulate, concentric, crateriform ; the yellowish white 

 colony lines the bottom ; microscopically, a brownish yellow granular cen- 

 tre, and a less dense granular border, with radial extensions. 



Gelatin stab. In 3 to 4 days liquefaction extends along the line of the needle ; 

 on the surface, a bubble of gas lined with a yellowish white growth ; a 

 yellowish white sediment in the liquefied gelatin, and a pellicle on the 

 surface. 



