﻿EFFECT OF LIGHT UPON THE GERMINATION OF SPORES 

 AND THE GAMETOPHYTE OF FERNS. 



BY A. C. LIFE. 



While germinating fern spores in 1905 at the Missouri 

 Botanical Garden, for the purpose of producing material for 

 a morphological study, it was noticed that different intensities 

 of light had a decided effect upon germination. A perusal of 

 the literature revealed conflicting results by different investi- 

 gators. It was then thought worth while to verify the work, 

 or at least attempt to clear up the discrepancies of the earlier 

 investigators. Consequently, in the early part of 1906, ex- 

 perimentation was begun with different intensities of light. 



Historical. 



The earliest definite experimentation upon the effect of 

 light upon fern spore germination was that of Borodin in 1868. 

 He worked mainly with the spores of Aspidmm spinulosum 

 and Aneimia phyllitidis, and was not able to obtain germina- 

 tion in darkness. The exposure of some of the spores to light 

 after they had been in the dark 18 days, was sufficient to 

 bring about germination in 9 days after they were removed 

 from darkness. He also experimented with spores oi As- 

 plenium, Allosorus, Polypodium and Phegopteris, and obtained 

 no germination in the dark. Schmidt also was not able to 

 secure germination of the spores of Aspidium violascens and 

 Aspidium filix mas in the absence of light. His work was in 

 1870, two years later than that of Borodin. 



Goeppert in 1869 germinated spores of Osmunda in dark- 

 ness, while Kny in 1872 could not verify his results. 



Schelting in 1875 reported germination of Pteris aquilina, 

 Aneimia phyllitidis, and two species of Aspidium in darkness 

 at a temperature higher than the ordinary room temperature. 

 In 1878, in his experiments with Scolopendrium, Beck found 

 that Ught of a certain intensity was necessary for the germina- 

 tion of the spores. The spores of Equiselum, with respect to 



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