— 51 — 



five days being required after the exposure to light. In the 

 other three series of cultures at 27°, 24° and 23°, no apparent 

 retardation of germination was noticed when the spores were 

 exposed to light. 



The above experiments liave shown clearly that a conti- 

 nuous exposure to high temperatures is not sufficient to produce 

 germination of the moss spores in the dark. As suggested 

 by the results obtained by Liebenberg 1 for seeds of Poa, it 

 was thought that perhaps a change of temperature might be 

 effective in producing germination. To this end the following 

 experiments were carried out. Two cultures of Funaria 

 hygrometrica spores were placed in the dark for twelve hours, 

 then in the thermostat at 41° C, for four hours. The cultures 

 were then removed and one placed in light, the other in the 

 dark, both at a temperature of 19 — 21° C. After three days 

 the spores in the light had germinated abundantly, but those 

 in the dark showed no signs of growth, although they were 

 kept for two weeks. Similar cultures were exposed to a 

 temperature of 41° C for three hours with the same result. 



Cultures similar to the above were made for Funaria 

 hygrometrica, Bryum pendulum, and Brachythecium rutabulum 

 and exposed to a temperature of 32° C for twenty four hours. 

 At the end of this time they were placed at the ordinary 

 temperature, the control experiments in the light, the others 

 in the dark. Those in the light germinated after the usual 

 length of time, but in the dark no signs whatever of ger- 

 mination were noted. Thus, change of temperature is also 

 shown to be insufficient in producing germination in complete 

 darkness. 



It is known that ether has a stimulating influence on 

 the production of shoots from certain phanerogams, when 

 under normal conditions none are produced. It might also 

 be supposed that it would act as a stimulant to call forth 

 the germination of spores in the dark. In order to determine 

 this point, a series of cultures was made in which the spores 



Bot. Centralblatt 14:21—26. 1884. 



4* 



