— ■ io6 — 



Phyto-physiological notes. 



In our last Report we have already referred to the work published 

 by E. Charabot and G. Laloue 1 ) on the formation and distribution 

 of terpene compounds in the sweet orange tree. We now abstract 

 from the last Report from Roure-Bertrand Fils 2 ) two interesting 

 studies on the formation and distribution of the essential oil 

 and on the gradual distribution of the terpene compounds 

 in the various organs of the plant. The experimental plant was 

 in both cases Artemisia absy?ithium L. The first-named experiments 

 showed once more that the essential oil is present in abundance in 

 the plant which is yet quite young. Up to the time of the flowering 

 season the content of odorous substances increases, also with regard 

 to the absolute quantity. But then a decrease in the percentage, as 

 well as in the absolute quantity of oil, takes place. This quantity of 

 oil is used up when after the flowering period the act of fructification 

 is accomplished. Although it is not excluded that during this period 

 a new formation of odorous substances takes place, it is not equal 

 to the quantity consumed. The conclusion drawn by Roure-Bertrand 

 Fils from the results obtained is this, that the essential oils in the 

 plant are recognised as the substances which are used up in the organism 

 in order to ensure the continuance of the species. The results are 

 reproduced graphically in the Report; they show that the root of the 

 young wormwood shrub does not yet contain any oil, the stalk 

 comparatively little, but that the leaf contains the bulk. At the 

 commencement of the flowering period the oil makes its appearance 

 in the root, where its quantity increases steadily, also according to 

 the absolute weight. The loss of essential oil which can be demonstrated 

 during fructification is borne by the leaves, stalks and inflorescences. 

 With regard to the distribution and development of the terpene 

 compounds in the organs of the plant, the examination included 

 the comparative determinations of the essential oil present in the 

 individual organs, as well as the relative solubility of the individual 

 constituents. A long time before the first inflorescences make their 

 appearance, the essential oil of the plant only contains traces of 

 thujone; the oil of the stalks is more difficult soluble than that 

 of the leaves. Immediately after the occurrence of the first inflorescences, 

 the oil contained in these also shows a lower solubility than the oil 

 of the leaves. The ester-content is largest in the roots, and smaller in 

 the stalks, inflorescences and leaves. The content of free thujyl alcohol 

 does not differ largely in the various organs of the plant. Thujone is 

 chiefly present in the lc#f es, and only traces of it are found in the stalks. 



1 ) Compt. rend. 142 (1906), 798; comp. Report April 1906, 104. 



2 ) Berichte, Roure-fiertrand Fils, April 1906, 1. 





