[Vol. 10 



258 



ANNALS OF THE MISSOURI BOTANICAL GARDEN 



The data concerning the solution in which the mats were 

 grown is given in table xi. It will be noted that 1 flask of each 

 3 was permitted to grow an additional period of 6 days, the 

 original inoculations all being made on the same date. 



TABLE XI 



HYDROGEN-ION CONCENTRATION AND TITER OF CULTURE SOLUTION 



AFTER GROWTH OF FUNGOUS MATS 



Organism 



Ph 



Cc. N/10 NaOII 



Period (days) 



Blank 



4.4 



5.15 



8* 



4 



6.5 



2.35 



8* 



4 



6.8 



1.4 



14 



9 



1.8 



57.5 



8 



9 



2.1 



37.7 



14 



2 



7.5 



1.05 



9 



2 



7.8 







15 



3 



5.4 



6 25 



9 



3 



6.7 



1.2 



15 



T 



6.4 



3.05 



10 



7 



6.8 



2.0 



16 



11 



5.0 



5.12 



10 



11 



5.0 



8.5 



16 



* Data for the shorter periods represent averages of two cultures, for the longer 

 periods one culture. 



The results of the fermentation of the sugar solutions are given 

 in table xn. These solutions were run in 2 separate series. The 

 first series included KNO» and NH 4 NOi as nitrogen sources and 

 the second series, which followed after the first citric acid series, 

 contained all 3 nitrogen sources. The solutions are listed accord- 

 ing to the cation of the nitrogen-containing compound. 



The results obtained when using the citric acid solution are 

 given in table xin. The 9-day series was run after the first 

 sugar series and the 5-day series after the second sugar series. 



A survey of the data in tables xi, xn, and xin shows consid- 

 erable variation among the fungi used, and these variations indi- 

 cate in some measure the kind of reaction favorable to such a 

 fungus. Diplodia produced more acid from sugar in the presence 

 of NH<NO» than when KNO* and Ca(NO,) 2 were used, but in 

 the case of Aspergillus sp. the most acid was found when KNOi 

 was used. In the presence of KN0 3 the final titration of organism 



