THE DECOMPOSITION OF CELLULOSE IN SOILS 455 



11. Filter paper broths, 15 days. The paper is reduced to a thin white 



filmy mass which breaks up into minute particles on slight agita- 

 tion. The decomposition of the paper proceeds rapidly with am- 

 monium sulphate, potassium nitrate, peptone or casein as the 

 source of nitrogen. 

 Ill, Biochemical Features. 



12. Dunham's solution, 10 days. Ammonia formed ; nitrite formed. 



13. Starch nitrate solution, 10 days. No ammonia formed ; nitrite formed. 



14. Peptone nitrite solution, 10 days. Indol formed. 



15. Carbohydrate broths, 12 daj's. No gas produced. Per cent of acidity 



(Fuller's Scale) with: Dextrose, 1.20; Lactose, .75; Saccharose, 

 .80; Maltose, 1.00; Glycerine, .40; Mannite, .00; Starch, 1.00. 



Bacillus imminutus, n. sp. 



Source : Soil from Highland, California ; Berkeley, California ; Corona, Califor- 

 . nia; Redlands, California; Whittier, California; Santa Paula, California; 

 Pasadena, California; Azusa, California; Fullerton, California; Porterville, 

 California. 



I, Morphology. 



1. Vegetative cells : Average dimensions 1.5 x .2 fi. The vegetative cells 



pass quickly into involution forms which frequently attain a length 

 of from 6 to 8 ^ without increasing in thickness. The involution 

 forms are commonly curved cells, frequently more or less fusi- 

 form. 



2. Endospores : Form, round; average size, .5 fi] germination, polar. 



Rod is swollen during germination, giving the cell a drumstick 

 appearance. On cellulose agar the spores appear in from 4 to 6 

 days. 



3. Flagella : 1 to 5 in number ; 3 to 5 fi in length. 



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



dyes. 



II. Cultural Characteristics. 



5. Agar strokes, 5 days. 

 Beef agar: No growth. 



Potato agar: No growth. ' ' 



Peptone starch agar: No growth. 



6. Potato cylinders: No growth in 30 days. 



7. Gelatine stab: No growth in 30 days. 



8. Beef broth, 5 days : No growth. 



9. Litmus milk: No growth in 30 days. 

 10. Plate cultures. 



Ammonia cellulose agar, 15 days. 



Form : Round. 



Size : The size of the colonies is quite variable ; after 15 days 

 the diameter is usually between 12 and 15 mm. The colony 

 continues to increase in size as long as the medium remains 

 moist, and where plates can be kept free from molds a single 

 colony may eventually cover the entire plate. The round form 

 of the colony is maintained as long as the growth is unob- 

 structed. 



