112 ACTINOMYCETES 



face growth thin, flat, yellowish drab. Aerial mycelium deep olive-buff. 

 Soluble pigment pale orange-yellow. 



Synthetic glucose agar: Growth thin, flat, covered by olive-buff aerial 

 mycelium. Soluble pigment green. 



Nutrient potato agar: Growth wrinkled, grayish. Aerial mycelium white 

 to vinaceous-f awn-colored. Soluble pigment golden brown. 



Potato: Growth good, covered with deep olive-buff aerial mycelium. 

 Soluble pigment gray to olive to black. 



Gelatin: Growth pale gray, covered with scant white aerial mycelium. 

 Liquefaction rapid. Soluble pigment yellow. 



Milk: Growth good, covered with white aerial mycelium. Coagulation 

 followed by incomplete peptonization. 



Starch: Hydrolysis. 



Glucose broth: Surface and bottom growth good, whitish. Aerial myce- 

 lium abundant, wrinkled, olive-buff. Soluble pigment golden brown. 



Nitrate: No reduction. 



Glycerol synthetic solution: Growth, mostly at bottom, white, flaky. 

 Aerial mycelium scant, olive-buff. 



Tyrosinase reaction: Negative. 



Habitat: Potato scab. 



128. Streptomyces marginatus (Millard and Burr) comb. nov. (Mil- 

 lard, W. A., and Burr. S., Ann. Appl. Biol., 13, 1926, 580.) 



Aerial mycelium: Abundant, gray to yellow to olive-buff. Sporophores 

 simple; spores spherical, 0.87 by 0.8 /x. 



Synthetic sucrose agar: Growth thin, echinate, covered with abundant 

 olive-buff aerial mycelium. Pigment cream-colored. 



Synthetic glucose agar: Growth thin, yellowish, covered with white to 

 buff aerial mycelium. Soluble pigment buff. 



Nutrient potato agar : Growth heavy, gray, covered with white to whitish 

 yellow aerial mycelium. Soluble pigment light golden brown to deep golden 

 brown. 



Potato: Growth good, raised, covered with abundant buff to olive-buff 

 aerial mycelium. Plug at first gray, later becoming black. 



Gelatin: Growth thin, pale olive-gray, covered with abundant pale gray 

 to olive-buff aerial mycelium. Soluble pigment buff. 



Milk: Growth good, flocculated; aerial mycelium white. Coagulation 

 followed by peptonization. 



Starch: Hydrolysis. 



Glucose broth: White spongy mass at surface and on bottom, covered 

 with white to yellow aerial mycelium. Soluble pigment light golden brown. 



Nitrate: Reduction. 



