— 47 — 



special raethods will be described in connection with the 

 experiments themselves. 



a. MOSS SPORES. 



First as to the experiments with moss spores. Cultures 

 of Funaria hygrometrica spores were made, and in one case 

 exposed to normal illumination, and in another placed in the 

 dark Chamber ; both being kept at a temperature varying from 

 19 — 21° C. At the end of three days the spores exposed to 

 light had germinated abundantly, while those in the dark 

 Chamber showed no signs of germination, not even a bursting 

 of the exospore. The dark culture was kept for a month 

 and at the end of that time there was no indication of ger- 

 mination. That the spores had remained normal and had 

 not lost their power of growth was shown by their speedy 

 germination when exposed to ordinary illumination. This 

 experiment was repeated several times with the sarae result. 

 Similar experiments were carried out with spores of Brachy- 

 thecium rutabulum, Bryum pendulum, and Mnium cuspidatum 

 and all revealed the same dependence of germination upon 

 illumination. 



In order to determine which part of the spectrum was 

 effective in producing germination, cultures of spores were 

 placed under double-walled bell-glasses filled respectively 

 with potassium bichromate and ammoniated copper oxide. 

 The cultures included Funaria hygrometrica, Bryum pendulum 

 and Brachythecium rutabulum. At the end of three days 

 the spores exposed to the less refrangible rays of the spec- 

 trum had germinated with as great readiness as under normal 

 illumination, while the cultures in the blue light showed no 

 signs of germinating, thus acting the same as in darkness. 

 The spores although retained in the blue light for over a 

 month showed no germination whatever. The failure of the 

 spores to germinate in the strongly refrangible rays would 

 seem to throw some light upon the processes which occur in 

 germination. Although the spores form some Chlorophyll in 

 the blue light, the photosyntactic processes are not active, 



