Jan. 38, 1918 



Nitrogen- A ssimilating Bacteria 



209 



Table XXI. — Influence of sodium nitrate on Bacillus radicicola in sterilized soil 



a Contamination. 

 Table XXII. — Influence 0/ calcium nitrate on Bacillus radicicola in sterilized soil 



An inspection of all three tables reveals two marked differences from 

 the results obtained in similar woric with Azotobacter. First, it will be 

 noted that nitrates do not appear to exert such a marked stimulating 

 effect with B. radicicola as with Azotobacter. The numerical increase 

 due to the presence of the nitrate is clearly shown in the percentage 

 columns. Second, it will be noted that B. radicicola does not seem to be 

 so sensitive to higher concentrations of nitrates as does Azotobacter. 

 In all instances at concentrations equivalent to 300 mgm. of nitrate in 



