﻿GERMINATION AND GAMETOPHYTE OF FERNS. 



Ill 



were able to germinate in darkness in both sugar solutions 

 and inorganic solutions, especially Knop's solution. How- 

 ever, Alsophila australis, Asplenium lucidum, and Poly- 

 podium aureum could not be induced to germinate in dark- 

 ness under any conditions. Laage further claimed that there 

 was no new formation of chlorophyll in darkness. 



The Ophioglossaceae are reported to germinate in dark- 

 ness. Hofmeister found prothallia of Botrychium lunarw, 

 three inches beneath the surface. Arcangeli reports the germi- 

 nation of PUularia, and Woronew the same for Marsilia in 

 the absence of light. Each of these investigators of the 

 water ferns claims there is new formation of chlorophyll in 

 the absence of light, especially in the germination of the 

 megaspore. 



Much less work has been done upon the effect of light upon 

 the prothallium and sex organs than has been done upon 

 germination. In 1879 Prantl reported that strong light pro- 

 duced a growth of archegonia, of course on the shaded side 

 of the prothallium, and that weak light tended to produce 

 only antheridia. The effect of light upon the dorsiventrality 

 of prothallia had been worked upon earlier by Prantl and 

 others. 



Methods. 



The spores which were sown in the progress of this experi- 

 mental work were almost all collected at the Missouri Bo- 

 tanical Garden, and sowed soon after collection. They were 

 collected at any and all times of the year, and germinated 

 almost as well in winter as at other seasons. The Alsophila 

 australis spores germinated after a rest of about a year after 

 collection. The spores of other ferns which were worked 

 with, germinated well when sown as soon as they were 

 thoroughly dry. 



The spores were nearly all germinated in specially prepared 

 boxes with sliding glass covers. These boxes were filled to a 

 depth of about six inches with sterilized garden soil. The 

 pots in which the spores were sown were imbedded in this 

 soil, to a depth of about two-thirds of their height. To de- 

 termine the best medium upon which to sow the spores, ex- 



