74 



PHYSIOLOGICAL RELATIONS 



Relatively striking results have been obtained by Saida x with the 

 parasitic fungus, Plioma Beta. Some data from cultures seventy- 

 five days old with 50 cc. of media are as follows : 



Phoma Bet^e 



Substances added to a nutrient salt solution 2 



Cane sugar, in 

 grams 



Fixation of nitrogen, 

 in milligrams 



Cane sugar 



Cane sugar 



Cane sugar (+ (NH 4 ) 2 C03, trace) 

 Cane sugar (4- (NH^CC^, trace) 

 Cane sugar (+ (NH^COs, trace) 

 Cane sugar (+ (NH^COs, trace) 



5 

 17 



5 



10 

 20 

 3° 



•7393 

 1. 1828 

 1. 1828 

 1.7742 



3-5484 

 6.2097 



More recently Ternetz 3 has isolated five endophytic mycorhizal 

 fungi from certain Ericaceae, all of which have been found to be- 

 long to the form genus Phoma. Three of these organisms, viz., 

 Phoma radicis Vaccinii, Phoma radicis Oxycocci, and Phoma 

 radicis Andromedm, have shown a well-developed capacity for 

 nitrogen fixation in culture, these three mentioned working even 

 more economically than Azotobacter chroococcwn, the amount of 

 nitrogen fixation in milligrams per gram of dextrose used, being, 

 under the conditions of culture, respectively 22.14, 18.08, 10.92, 

 and 10.66 for the four organisms mentioned. 4 



The mineral nutrients may be supplied in the form of any of the 

 soluble salts, the neutral salts being, in general, preferable. Formulae 

 for culture solutions are, however, given under nutrient media. 



1 Saida, K. Ueber Assimilation freien Stickstoffes durch Schimmelpilze. Ber. 

 d. deut. bot. Ges. 19 : (io7)-(ii5). 1901. 



2 This solution was constituted as follows : 



KH 2 P0 4 0.4 



MgS0 4 0.4 



CaCl 2 trace 



Water 100 cc. 



3 Ternetz, Charlotte. Ueber die Assimilation des atmospharischen Stickstoffes 

 durch Pilze. Jahr. f. wiss. Bot. 44 : 353-408. 1907. 



4 Other papers of interest in connection with the fixation of nitrogen by fungi 

 are the following : 



Puriewitsch, K. Ueber Stickstoffassimilation bei den Schimmelpilzen. Ber. d. 



deut. bot. Ges. 13: 342-345. 1895. 

 Froehlich, H. Stickstoffbindung durch einige auf abgestorbenen Pflanzen haufige 



Hyphomyceten. Jahr f. wiss. Bot. 45 : 256-302. 1907. 



