212 



ANNALS OF THE MISSOURI BOTANICAL GARDEN 



[Vol. 6 



0l_ 



90 



£ 





.<S 





£ 



80 



5 





^ 





i 



70 



i 



60 



\so 



t 



40 



^ 





1 



30 



s 







ZO 



/o 



Ph 



2 



T 

 J 



T 



4- 



S 



to 



Fig. 1. Aspergillus niger. Graphic representation of the relation of germi- 

 nation to H ion concentration. 



The data obtained with spores of Penicillium cyclopium as 

 given in table n, are somewhat similar to those with Aspergillus 



niger. 



TABLE II 



PENICILLIUM CYCLOPIUM. AVERAGE PERCENTAGES OF SPORE GERMINATION IN 



M/5 MANNITE AT DIFFERENT TEMPERATURES AND AT VARIOUS 



HYDROGEN ION CONCENTRATIONS 



Temp. 



Hrs. 



Hydrogen ion concentration, P H 



2.8 



3.1 



4.4 



5.0 



6.2 



7.0 



7.4 



8.8 



9.6 



10.0+ 



22° C. 



18 

 27 

 37 



18 



27 

 37 



18 

 27 



4.1 



10.3 

 11.4 



13.5 

 21.1 



22 . 7 



16.8 

 30.7 

 32.3 



22.9 

 52.2 

 55 . 4 



1 

 14.0 



16.6 

 23 . 6 



7.1 

 10.9 

 11.9 



10 . 5 



18.1 

 22.0 



9.7 

 19.5 



6.6 

 8.1 

 8.6 



10.5 



28.7 

 31.9 



4.4 

 10.5 

 13.0 



2.1 



2.7 

 3.1 



0.0 

 0.0 

 1.7 



27° C. 



32.2 



58 . 6 

 59.8 



15.0 

 30.0 



35.5 

 65.6 

 66.6 



20 .7 

 32 5 

 35 1 



1 3 . 4 



25 . 2 



12.3 



28.7 



33.2 



7.0 

 12.1 



18.7 



9.6 

 12.1 



0.0 

 0.0 

 0.0 



0.0 

 0.0 

 0.0 



0.0 

 0.0 



0.0 

 0.0 

 0.0 



31° C. 



44.2 



57.8 



29.3 

 39 . 3 



5.6 

 6.8 



0.0 

 5.0 



0.0 

 0.0 



When incubated 



o 



C. for 18 hours, maximum 



obtained 



the culture 



of P 



hyd 



concentration 



H 



dec 



hydrog 



