28 BOTANICAL GAZETTE [JULY 
ber; both being kept at a temperature varying from 19~-21° C, 
At the end of three days the spores exposed to light had germi- 
nated 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 germination. 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 same result. Similar experiments were carried out with 
spores of Brachythecium 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 effec- 
tive in producing germination, cultures ot spores were placed 
under double-walled bell-glasses filled respectively with potas- 
sium 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 spectrum had germinated with as 
great readiness as under normal illumination, while the cultures 
in the blue light showed no signs of germination, 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 refran- 
gible 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, and hence it might be thought that germination 
depended upon the elaboration of new material which can only 
occur to any extent in the less refrangible rays. That this view 
is highly improbable is shown by the experiments which follow. 
Cultures of spores were made of the three species above 
mentioned and placed in the light in air free from CO,, the 
apparatus being the same as that figured by Pfeffer." The first : 
** Pflanzenphysiologie 4: 191. 1881, 
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