MEMOIRS OF THE NEW YORK BOTANICAL GARDEN. 7 



eralization that etiolated plants contained 2 per cent, more water than 

 normal specimens. The ash constituent showed an increase of 4 per 

 cent, and the proportion of carbon decreased. Measurements of 

 root systems suggested a more marked development of these organs 

 than those of plants in light. 



Guillemin ^* states that etiolated plants developed green color more 

 rapidly in blue, yellow, green, and orange or red, than in direct sun- 

 light, and that the action of yellow light was equal to that of diffuse 

 daylight. 



The chemical nature of chlorophyl and the manner of its forma- 

 tion engaged the attention of a number of authors. Gris^" made a 

 series of investigations upon the behavior of chloroplasts and the for- 

 mation of chlorophyl in 1857 '^^ which he etiolated plants of Senifer- 

 vivnm tectorum, S. Hazvorihu, Sediun dendroidetim, Aloe obh'gtia, 

 Vicia Faba, Oxalis, bean and erythrine. Chloroplasts appeared to 

 diminish in size during the process of blanching. Some data were 

 given by him concerning the form and character of the protoplasm 

 of etiolated organs to which reference will be made in a later part of 

 this paper. 



Sachs ^^ began the study of etiolation phenomena and the publica- 

 tion of his results in 1859, ^^^ interest in this subject was most ac- 

 tive in the decade following, numbers of investigations being carried 

 on in the Wiirzburger laboratory by Sachs and his students, and by 

 other workers in Germany, France and England. 



Sachs' ^' earliest observations were concerned with the relations of 

 light to chlorophyl principally, as well as the origin of starch, but as 

 may be seen a widening attention was given the subject, and growth, 

 development, and stature of etiolated plants were dealt with in great 

 detail. Sachs saw the construction of chlorophyl in cells in which 



^^Guillemin, C. M. Production de la chlorophjlle, et direction des tiges sous Tin, 

 fluence des rajons ultra-violets, calorifiques. et lumineux du spectre solaire. Ann. Sc. 

 Nat. IV. 7: 154. 1857. ■ 



^^Gris, A. De etiolement. Recherches microscopiques sur la chlorophylle. Ann. 

 Nat. Sci. IV. 7: 207. 1857. 



3°Sachs. Handbuch d. ph\'siol. Bot. 1S65. See Lotos, Jan. 1859. 



^' Sachs. Ueber den Einfluss des Lichtes auf die Bildung des Amjlums in den 

 Chlorophyllkornern. Bot. Zeitung, 20: 365. 1S62. 



Sachs. Uebersicht der Ergebnisse der neueren Untersuchungen ueber das Chlo- 

 rophjll. Flora, 45: 129. 1862. 



Sachs. Ueber den EinHuss des Tageslichtes auf Neubildung und Entfaltung 

 verschiedener Pflanzenorgane. Bot. Zeitung, 21: Beil. 31. 1863. 



