448 SOIL SCIENCE 



11. Filter paper broths, 15 daj's. Paper reduced to a loose, felt-like mass 



which retains the pure white color of the paper. The structure of 

 the paper has been entirely destroyed, as can be easily demon- 

 strated by the slight agitation of the solution. The decomposition 

 of the paper was less rapid with casein or potassium nitrate as the 

 source of nitrogen than with peptone or ammonium sulphate. 

 III. Biochemical Features. 



12. Dunham's solution, 10 days : No ammonia produced ; no nitrite pro- 



duced. 



13. Starch nitrate broth, 10 days : No ammonia produced ; no nitrite pro- 



duced. 



14. Peptone nitrite solution, 10 days: No indol produced. 



15. Carbohydrate broths, 12 days: No gas produced. Per cent of acidity 



(Fuller's Scale) with: Dextrose, 1.30; Lactose, .80; Saccharose, 

 1.00; Maltose, 1.20; Glycerine, .40; Mannite, .00; Starch, .60. 



Bacillus concitatus, n. sp. 

 Source : Soil from Barstow, California ; Covina, California ; Riverside, California. 



I. Morphology. 



1. Vegetative cells : Average dimensions, 1.2 x .5 fi. 



2. Endospores : None observed. 



3. Flagella : 1 to 3 in number ; 3 to 4 ^^ in length. 



4. Staining reactions : Gram negative. Stains readily with the aniline 



dyes. 



II, Cultural Characteristics. 



5. Agar strokes, 5 days. 



Beef agar: Abundant, flat, moist, yellowish white. 



Potato agar: Abundant, raised, moist, glistening, grayish white; old 



cultures become somewhat yellowish white. 

 Peptone starch agar: Abundant, raised, frequently somewhat rugose, 



grayish white. 



6. Potato cylinders: No growth in 30 days. 



7. Gelatin stab: Moderate growth at surface and along stab in 5 days; 



slight napiform liquefaction after 30 days. 



8. Beef broth, 5 days: Heavily clouded. 



9. Litmus milk: Reddened in 4 days; no curdling or digestion apparent 



after 30 days. 

 10. Plate cultures. 



Ammonia cellulose agar, 15 days. 



Form : Surface colonies are round or irregularly round ; bottom 

 colonies spread out into irregular somewhat amoeboid growths. 



Size : Surface colonies are from 1 to 5 mm. ; bottom colonies fre- 

 quently attain a diameter of 15 mm. 



Enzymic zone : Surface colonies, 1 to 1.5 mm. ; bottom colonies 

 sometimes show no enzymic zone, but the colony is always 

 more transparent than the surrounding medium, showing that 

 some of the cellulose within the colony has been dissolved. 



Elevation : Flat or slightly depressed. 



Chromogenesis : Many of the colonies are almost pure white, 

 while others show very thin brownish rings. 



Internal structure : Brownish rings coarsely granular ; remainder 

 of colony finely granular. 



Edge : Entire. 



