362 BACTERIOLOGY 



found in the deeper portions of the culture. Filaments, but not the 



capsular enlargements, stained by Oram's method. 

 Gelatin colonies. Irregular, yellowish gray, glistening; microscopically, dark 



yellowish gray, homogeneous or slightly concentric ; border dark, with a 



fine filamentous structure. 

 Gelatin stab. In depth, small yellowish white spheres, which become bristly ; 



on the surface, growth yellowish white, flat, raised, soft, glistening, rather 



tough, becoming sunken, due to a slight liquefaction ; liquefied gelatin 



syrupy, brownish. 

 Agar slant. Growth of delicate colonies, becoming whitish to whitish yellow, 



soft, glistening, raised, warty, becoming sunken and brownish in color. 



The growth penetrates deep into the medium. 

 Blood serum. Isolated colonies becoming spreading and thicker, rather dry; 



the lower surface of the growth in contact with the medium, orange-yel- 

 low brick-red. 

 Bouillon. Remains clear ; at the bottom globular masses. 

 Milk. Unchanged in 8 days. 

 Potato. Growth warty, yellowish white, very adherent, limited. Odor of 



cultures weak, not mouldy. 

 Glucose bouillon. No gas, acid. H 2 S negative. 

 Pathogenesis. Intraperitoneal inoculations of guinea pigs and rabbits result, 



in 30 days, in the formation of nodules on the peritoneum containing the 



fungus. 

 Habitat. Associated with antinomycosis in man and cattle. 



2. Streptothrix flava 



Described by Bruns: Centralblatt f. Bakteriol., XXVI, 1899, II. 



Morphology. Filaments 1-2 ft broad and reaching 100 fi in length, often with 

 clavate swellings. Filaments show branching, also shorter forms like 

 Mycobact. diphtheria!. Stain by Gram's method. 



On agar, after 3-4 weeks, a colony 0.75-1.0 cm., yellowish. Surface irregular, 

 adherent, not easily fragile. 



In bouillon, a whitish yellow, fragmentary growth on the bottom; no growth 

 on the surface ; fluid clear. Grows on blood serum and potato, but not 

 so well on agar. On gelatin, at 24-26, a slight growth after 4 weeks; 

 no liquefaction. Optimum temperature, 35-38 ; minimum, 25. 5 C. 



Pathogenesis. Non-pathogenic to mice, guinea pigs, and rabbits. 



