1919] 



WEBB — SPORE GERMINATION AND H ION CONCENTRATION 



217 



90 



%60 



% 70 



\eo 



\.50 



\zo 



\ IO 



Ph 



10 



Fig. 5. Lenzites saepiaria. 

 nation to H ion concentration. 



Graphic representation of the relation of germi- 



passed, germination decreases rapidly and appears to be totally 



inhibited at P H 10.0 + . 



With an additional incubation of fourteen hours, the order 

 of germination on the acid side shifts considerably, while that 

 on the alkaline side remains practically the same. 



Sli 



germination is obtained 



H 



with the maximum on the acid 



side occurring at P H 3.1, and these are the only 



nificant 



chan 



A series was also incubated 



C, but on findin 



of the solutions had become contaminated, the data 



discarded 



In fie. 4 are shown the germination curves for 



tern 



Very uniform data are obtained with the spores of Lenzites 

 saepiaria, as shown by table v. 



TABLE V 



LENZITES SAEPIARIA. AVERAGE PERCENTAGES OF SPORE GERMINATION IN 

 M/5 MANNITE AT 25° C. AND AT VARIOUS HYDROGEN ION CONCENTRATIONS 



Hrs. 



Hydrogen ion concentration, P« 



2.8 



3.1 



4.4 



5.0 



6.2 



7.0 



" 



7.4 



8.8 



9.6 



10.0+ 





" 





18 



30 





23.6 

 40.4 



66.3 



87.4 



43.3 

 49.3 



32.1 

 37.4 



28.3 

 32.2 



6.5 



8.6 



" 



0.0 

 0.0 



0.0 

 0.0 



0.0 

 0.0 



0.0 

 0.0 







