292 EECORD OF CUBRENT RESEARCHES RELATING TO 



plants raised from foreign seed; the experiments being made with 

 wheat from Bessarabia and Ohio. The general results attained may 

 be stated as follows : — 



1. The grain of wheat that has been grown in low-lying lands 

 may be propagated with success on the high fjaelds, and will reach 

 maturity earlier at such elevations, even although at a lower mean 

 temperature. Such grain, after having been raised for several years 

 at the highest elevation which admits of its cultivation, is found, 

 when transferred to its original locality, to ripen earlier than the 

 other crops which had not been moved. The same result is noticeable 

 in grain that has been transported from a southern to a more northern 

 locality, and vice versa. 



2. tSeeds imported from a southern locality, when sown within the 

 limits compatible with their cultivation, increase in size and weight ; 

 and these same seeds, when restored from a more northern locality to 

 their original southern home, gradually diminish to their former 

 dimensions. A similar change is observable in the leaves and 

 blossoms of various kinds of trees and other plants. Further, it is 

 found that plants raised from seed ripened in a northern locality are 

 hardier, as well as larger, than those grown in the south, and are 

 better able to resist excessive cold. 



3. The further north we go, within certain fixed limits, the more 

 energetic is the development of the pigments in flowers, leaves, and 

 seeds. Similarly, the aroma or flavour of various plants or fruits is 

 augmented in intensity the further north they are carried within the 

 limits of their capacity for cultivation ; and, conversely, the quantity 

 of saccharine matter diminishes in proportion as the plant is carried 

 further northward. 



Heliotropism of Hartwegia comosa (CMorophytum).* — Accord- 

 ing to M. Prillieux, the roots of this plant are negatively heliotropic, 

 lengthening both by day and by night. Contrary to the view of De 

 Wolkopf and H, Miiller, he believes that this phenomenon is due to 

 the increased amount of growth on the illuminated side ; growth being 

 promoted by the action of light. 



Influence of the Electric Light upon Vegetation. — At the Eoyal 

 Society on 4th March, Dr. C. W. Siemens gave a detailed description 

 of some experiments which he had made to determine whether electric 

 light exercised any decided effect upon the growth of plants. 



The method pursued was to plant quick-growing seeds and plants, 

 such as mustard, carrots, swedes, beans, cucumbers, and melons, in 

 pots, and these pots were divided into three groups ; one group was 

 exposed to daylight alone, a second similar group was exposed to 

 electric light during eleven hours of the night, and were kept in a 

 dark chamber during the daytime, and the third similar group was 

 exposed to eleven hours' day and eleven hours' electric light. These 

 experiments were continued during four days and nights consecutively, 

 and the results observed were of a very striking and decisive cha- 

 racter. The plants that had been exposed to daylight alone (com- 

 * ♦ Bull. Soc. Bot. France,' xxvii. (1879) p. 240. 



