MEMOIRS OF THE NEW YORK BOTANICAL GARDEN. 29 



retarding effect of light as a direct action may be drawn from these 

 observations. 



The observations of Stameroff ^"- offer some important and accurate 

 evidence upon the influence of light upon the growth of fungi. Veg- 

 etative hyphae of Miicor and Saprolegnia show the same rate of 

 growth in light and in darkness, while light is found to retard the 

 elongation of the sporophores of Mucor in corroboration of Vines' 

 experiments upon these organs, but it was not made clear that such 

 retardation was not due partiality or wholly to altered transpiratory 

 conditions. Similar retarding action was observed in rhizoids of Mar- 

 chantia polymorfha. The growth of pollen tubes of Colutca arbo- 

 rcscens and Robinia pseudacact'a was not affected by light. 



Mucor Jiavidus was seen by Lendner'"^ to produce spores only in 

 light ; Mucor racemosus developed sporangia in darkness but ma- 

 tured spores only in light. Many species of moulds were found to 

 show an excessive elongation of the sporophores in darkness. 



Curtei '"^ made extensive observations upon the influence of diffuse 

 light upon flowers. He concluded that flowers were less brilliant in 

 color, and fewer in number, and that the peduncles were longer and 

 more slender in diffuse light than in direct illumination. The corolla 

 showed the greatest amount of change, and the stamens and pistils 

 the least. The fruits w^ere smaller and fewer in diffuse light. All 

 of these manifestations might not appear in an}^ one individual. 

 Very diffuse light rendered flower formation impossible and strong 

 diffuse light was quite as favorable as the direct rays. The reactions 

 in question were ascribed to disturbances in nutrition. 



Green ^"^ investigated the effect of light upon enzymes in plants 

 and found that rays located in the red, orange and blue regions 

 caused an increase in the amount of diastase present during the ear- 

 lier part of the illumination and later acted deleteriously. The vio- 

 let and ultra-violet rays exerted a constant disintegrating effect. 

 The action of light upon the diastase or enzymes of a cell is, of 

 course, greatly modified by the character of the external membranes, 



'^2 Stameroff, K. Zur Frage iiber den Einfluss des Lichtes auf das Wachslum der 

 Pflanzen. Flora, 83 : 135. 1S97. 



'°3 Lendner, A. Des influences combinees de la lumiere et du substratum sur le 

 developpement des champignons. Ann. Sc. Nat. VIII. 3 : 60. 1867. 



""Curtei, M. Y. Recherches physiologiques sur la fleur. Ann. Sc. Nat. VIII. 6: 

 220. ibigy. 



'05 Green, J. R. Action of Light on Diastase, and its Biological Significance. 

 Proc. Roy. Soc. 188: 167. 1S97. 



