[Vol. 10 



162 



ANNALS OF THE MISSOURI BOTANICAL GARDEN 



become apparent until about the sixteenth day. It first ap- 

 peared as a few hyphae clinging to the sides of the flasks and 

 increased so slowly that at the end of 34 days the amount was 

 judged to be not more than 20 to 30 mgs. dry weight, and at the 

 end of 20 days more little, if any more, growth occurred. The 

 fungus is apparently able to live in contact with a solution as 



5 



10 



15 



20 



25 



30 



35 



Fig. 12. 



acid as P H 2.5, but makes very slow growth; while at P H 3 growth 

 is slow until the fungus is able to bring about a more favorable 

 reaction, whereupon growth increases rapidly. 



All cultures on the acid side of P H 7 steadily became less acid 

 as growth advanced, reaching approximately P H 7 by the time 

 maximum growth was attained, and becoming distinctly alkaline 

 thereafter. Cultures started at P H 7 or above first became less 

 alkaline, then reversed the direction of change and became more 



