32 



>. 



MISSOURI BOTANICAL GARDEN 



some effect, but from the results of the experiment it is evident 

 that but Httlc light if any is necessary to cause some at least 

 of the seeds to germinate. This, in the writer's opinion, is 

 the explanation of the jpresence of this tree as a hammock 

 inhabitant; without assuming the epiphyte habit. 



. There are but few plants known the seeds of which possess 

 the peculiarity described above for Ficus aurea. Pfeffer"^ re- 

 fers to Wiesncr'sf observation that the seeds of Viscum alhum^ 

 likewise epiphytic in habit, require light for their germination 

 although this does not hold true for tropical species of Viscum 

 nor for Lomnthus europaeiis. For the tropical Viscum species 

 germination is favored by light although it is not necessary. 

 In a footnote Pfeffer notes that Raciborski claims that light is 

 requisite for the germination of Nicotiaiia, It is of interest 

 that, while in Viscum album Hght is essential for germination 

 of a seed, the seedling thus produced turns away from the 

 light- This is not the case with cither Ficus aurea or F. 

 populneaj for their seedlings are very positively heliotropic. 

 The roots, on the other hand, arc rather distinctly nega- 

 tively heliotropic. Both features are shown fairly well in 

 plate 9 for F. aurea. In this respect these species are not 

 confirmatory of Davenport'sJ conclusion that the inability of 

 Viscum album to grow or germinate in the dark is correlated 

 with the peculiarity in its phototropic response that the hypo- 

 cotyl turns away from the light- 

 Subtropical Laboratory and Garden, 

 Miami; Florida. 



* PfefTer^ W, Pflanzenphysiologie, II Auflage. 



2 : 105. 



(1904). 



t Wiesner, J. Ueber die Ruheperiode und iiber einige Kcimungsbe- 

 dingungon dcr Samen von Visciim album, (Ber. Deutsch. Bot. Gesell. 

 15'^: 503-516. 1808). 



J Davenport. Experimental Morpliology. Part II. 423 and 438. 



ki 



