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MISSOURI BOTANICAL GARDEN. 



the effect of light upon their germination, were experimented 

 with by Sadebeck. He reported that light is not necessary 

 for their germination. 



The germination of the spores of liverworts was worl^ed 

 upon in 1876 by Leitgeb. He found that they neither germi- 

 nated in darkness nor very weak light. When germinated in 

 light they formed a germ-tube which was slightly negatively 

 geotropic. 



More recently Forest Heald in 1898 carried out a valuable 

 line of experimentation upon moss, fern, liverwort, and 

 equisetum spores. He secured germination of moss spores in 

 darkness by using either a sugar or a peptone solution as a 

 culture medium. Fern spores, especially those of Ceratop- 

 teris thalictroides and Alsophila Loddigesii, were made to 

 germinate at a temperature of 32° C. He was not able to cause 

 liverwort spores to germinate in darkness in sugar solution 

 at higher temperatures. He attributes his failure to the 

 effect of bacteria which grew in his cultures. Equisetum 

 spores germinated readily in ordinary media at ordinary 

 temperature in the dark. 



In 1901 Schulz obtained results that in some respects were 

 contradictory to those of Heald. He does not regard the 

 swelling of the moss spore in the sugar solution without light 

 as normal germination. Spores were germinated in blue as 

 well as yellow light, but required 30 days instead of 20 days, 

 the time required in yellow light. No germination of fern 

 spores in darkness at 30''-35°C was obtained, contradictory to 

 the work of Heald. To determine this, he worked with 

 spores of Gymnogramme chrysophylla, Aneimia phyllitidis, and 

 Alsophila australis. However, he was able to germinate 

 Ceratopteris thalictroides in 3 days in darkness at 30°-35°. 

 This agreed with the work of Heald. 



Treboux in 1905 verified the work of Heald in the germina- 

 tion of moss spores in sugar solution. He was also able to 

 secure germination in inorganic solutions. Further, he found 

 that the gemmae of Marchantia would grow into prothallia 

 in both organic and inorganic solutions in the absence of 

 light. 



In 1907 Laage reported that a great many species of ferns 



