300 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN. 



INFLUENCE OF ETIOLATION UPON CHEMICAL 

 COMPOSITION. 



A very noticeable effect of etiolation consists in the retarded 

 development of glandular organs and a diminution of the formation 

 of substances to which odors are due. 



DeCandolle '^^ was perhaps the first to record that " savours " and 

 " odours" were not so highly developed in etiolated plants, and simi- 

 lar facts were obtained by myself notably with Amorphophalhis, in 

 which the offensive odor is but little marked in individuals grown in 

 darkness. On the other hand, Schiibeler^™ found that north tem- 

 perate species taken northward and allowed to grow during the two 

 months' day in Scandinavia developed a noticeably larger amount 

 of aromatic and flavoring substances. This feature is also to be 

 seen in celery which has been properly blanched, the characteristic 

 flavor lacking some of the rankness found in fresh green stems. 

 Etiolation then may be looked to as a method of reducing the strong 

 and rank flavors of many plants in the effort to make them of eco- 

 nomic use, and Morren^"' estimated in 1863 that about two hundred 

 species of known plants might be capable of improvement as an arti- 

 cle of food by the etiolating treatment. It is to be seen however that 

 the etiolation of a plant does not actually increase the amount of ma- 

 terial of nutritive value to the human body. The chief merits of the 

 process consisting of the reduction of the ranker flavors and the 

 diminution of the amount of cellulose present, rendering the material 

 more attractive as food, and more easily masticated. 



The constant respiration carried on by etiolated plants must of 

 course result in the combustion of a large amount of plastic material, 

 while on the other hand not so much of the plastic substance is con- 

 verted into aplastic form in the manufacture of cell-walls in per- 

 manent tissues. According to the researches of Palladin "^^"^ etiolated 

 stems contain much less proteinaceous material than the normal. 



1"^ DeCandolle, A. P. Physiologic vegetale, 3: 1075. 1832. 



2°° Schtibeler. The effects of uninterrupted sunlight on plants. Nature, 21 : 311. 

 18S0. 



2"! Morren, E. La lumiere et la vegetation. La Belgique Horticole, 13.^: 165. 1863. 



^"^ Palladin, W. Eiweissgehalt der griinen und etiolirlen Blatter. Ber. d. deut. 

 Bot. Ges. 9 : 194. 1S91. 



