MEMOIRS OF THE NEW YORK BOTANICAL GARDEN. 5 



referring to the greater elongation of the stems which ensues under 

 such circumstances. 



Fries'^ as earl}^ as 1821 recognized the influence of light upon 

 fungi and saw that many forms including the Hymenomycetes, and 

 the Pezizaceae remain sterile and do not form spores when deprived 

 of illumination, and that many variations in form, notably excessive 

 elongation and branching, resulted from such treatment. Montague '^ 

 saw that light did not exert the same influence upon the mycelium 

 and sporophore, and Bonorden believed that the coloration of agarics 

 and other fungi was dependent upon light. In this last conclusion 

 however other mycologists were not agreed. The necessity of 

 illumination to induce the formation of spores was also recognized by 

 Tulasne.^*^ 



The period from 1820 to 1842 is devoid of literature upon the 

 relations of light to the higher plants in so far as the aspect of the 

 subject in question is concerned. The text-books appearing about 

 the latter date and preceding the wonderful renascence of botany 

 under the influence of Sachs appear to ignore the observations of the 

 mycologists and to assume that light could have an effect only upon 

 green plants.'' 



Beginning with the work of Payer" in 1842, several distinct series 

 of investigations upon the relations of green plants to light may be 

 distinguished. One dealt with the analysis of the values of the 

 different portions of the spectrum in the formation of food, the pro- 

 duction of curvatures and general influence upon growth. A second 

 was devoted chiefly to the formation and activity of chlorophyl, the 

 nature of chlorophyllary, synthetic and decomposition products. The 

 third, which was first taken up seriously by Sachs, was concerned 

 with the morphogenic influence of light and with all of the mulii- 



'8 Fries, E. Sjstema mjcologicum, i: 502. iS^i. Also 3: 265. 1839. And 

 Sjst. Orb. Veg. i : 212, 1825. 



"Montagne. Esquisse organographique et phjsiologique sur la classe champig- 

 nons. 1841. 



20Tulasne. Fungi hjpogaei. P. 2. 1852. 

 ^^ Leveille. Considerations mycologiques. 1846. 

 Bonorden. Handbuch der allgemeine Mykologie. 1851. 



Schmitz, J. Beitriige zur Anatomic und Physiologic der Schwamme. Linnaea, 

 17: 475. 1843. 



De Bary. Recherches sur le developpement de quelques champignons parasites. 

 Ann. Sc. Nat. IV. 20: 40, 54. 1863. 



"Payer. Mem. sur la tendance des racines a fuir la lumiere. Compt. rend. d. 1. 

 Acad. d. Sc. i : 1194. 1842. 



