360 



[Vol. 



ANNALS OF THE MISSOURI BOTANICAL GARDEN 







£ 



DAYS 



NM+ N(X 



KNO 



j 



ss 



DATsS 



Fig. 20. Nitrate N in 50 ml. media. Aspergillus niger, second series (top ; by dif- 

 ference); and third series (bottom; Strowd's method used). 



