ON ELECTROMOTIVE PHENOMENA IN PLANTS. 



225 



IV. Plumule 6 days 



396 00159 



0-0479 



286 



138 



Alterations of temperature give rise to considerable alterations of 

 magnitude of blaze-curi^ents and of electrical conductivity ; it is not 

 permissible, e.g., to compare effects observed at 15° and 25°; the 

 observations reported above were taken within the range of 18° to 20°. 



Influence of Temperature. — During the years 1898-1900, when one 

 of us was occupied with the examination of the physiological character 

 of the blaze-current and of the physical conditions by which it is 

 modified, systematic observations and records were taken of the in- 

 fluence of temperature which at that time were not written up, and 

 from which a repi'esentative experiment is now given in order to show 

 the range of the temperature modification. 



Our work during the last year, 1915, has been directed towards 

 determining whether Waller's blaze-currents can be used as a practical 

 test of the germination value of seeds. 



Our experiments have been carried on in collaboration with Mr. 

 D. Finlayson, who sends us samples from his Seed-Testing Labora- 

 tories. Wood Green, London, N. Our reports on seeds tested by 

 Dr. Waller's electrical method have corresponded exactly with Mr. 

 Finlayson 's reports by his seed-germination method. 



1915. 9 



