— 49 - 



content, Those spores which had begun to put out a proto- 

 nema filament, continued their growth somewhat, but the 

 filament was long and slender and did not attain any con- 

 siderable size on account of lack of plastic material. These 

 experiments were carried out with spores of Funaria hygro- 

 metrica, Bryum pendulum, and Brachythecium rutabulum, all 

 with the same result. Essentially the same fact has been 

 shown by Borodin 1 for fern spores. 



Leitgeb 2 has shown that for the germination of liver- 

 wort spores, a certain intensity of liglit is necessary, and 

 my experiments with moss spores show that the same thing 

 is true only to a less marke d extent. In experiments which 

 I conducted with Marchantia polymorpha spores, parallel 

 with the cultures of moss spores, where all were exposed 

 to the light in the middle of the laboratory, the different 

 behavior was very marked. The moss spores germinated in the 

 usual length of time and without any apparent modification 

 due to the weakness of the light. The Marchantia spores 

 on the other hand showed a very remarkable retardation 

 in germination, and when germination did occur, only a long 

 narrow filament was produced which gave no indication of 

 the formation of the thallus according to the ordinary methocl 

 of growth in sufficiently intense illumination. Other cultures 

 were made and exposed to a much weaker light, a room in 

 the Institute basement with only one window being used. 

 First, cultures were placed on a shelf at a distance of 

 about three meters from the window, then at two meters, 

 and then in the window itself. The cultures at a distance 

 of three and two meters from the window, showed a complete 

 failure of the spores to germinate, although they produced 

 Chlorophyll to some extent. Those which were grown in 

 the window, germinated after the ordinary length of time. 

 That the spores remained capable of germination was shown 

 by the fact that they began growth as soon as they were 

 exposed to normal illumination. These experiments then 



- 1. c p. 539. 



2 1. C. 



