1919] 



ALLEN — AZOTOIACTER CHROOCOCCUM 



29 



dium was used. One portion was boiled up with calcium car- 

 bonate and then filtered through a folded filter. The filtrate 

 was perfectly clear. Fifty-cc. portions were pipetted into 

 700-cc. "Nonsol" Erlenmeyer flasks, each containing a pinch 

 of calcium carbonate. A parallel series was set up, using the 

 unheated and unfiltered medium. After sterilization alter- 

 nate pairs of flasks in each series were inoculated with a spiral 

 of a 24-hour shaker culture of Azotobacter prepared by in- 

 oculating 10 cc. of Ashby's mannite solution in a 250-cc. Erlen- 

 meyer flask with a spiral of a 72-hour growth of Fio on Ashby 

 soil extract agar. 



One-half of each series was placed on the rotary shaker and 

 one-half on the shelf near by. The whole experiment was 

 carried out in the warm room, the temperature of which dur- 

 inff this particular period was very erratic. The first two days 







TABLE VII 



SERIES A— SOLID PHASE PRESENT 





No. 1 



Treatment 



Cond tion at close 



Nitrogen 

 (mgs.) 







Shaker 





1 



2 

 3 

 4 



Check 

 Check 



Inoc. 

 Inoc. 



Clear 

 Clear 



Strong turbidity, no floccules 

 Strong tu -bidity, floccules and slight 

 pigment 



0.62 

 0.59 

 5.10 



5.40 









Residual sugar 

 (mgs.) 



5 1 



6 



7 

 8 



Check 

 Check 

 Inoc. 

 Inoc. 



Clear 

 Clear 



Same as No. 4 

 Same as No. 4 



848. 



839. 

 0.0 

 0.0 





* 



Shelf 







Nitrogen 

 (mgs.) 



9 



10 

 11 



12 



Check 

 Check 

 Inoc. 

 Inoc. 



1 Clear 



Clear 



Good turbidity, some floccules 

 1 Good turbidity, some floccules 



0.72 

 0.65 

 3.34 

 2.97 





Residual sugar 

 (mgs.) 



13 

 14 

 15 

 16 



Check 

 Check 

 Inoc. 

 Inoc. 



Clear 



Clear 



Same as Nos. 11 and 12 



Same as Nos. 11 and 12 



820. 

 825. 

 449. 

 559. 



