36 HATCH EXPERIMENT STATION. [Jan. 



of these experiments the latent period varied from fifteen to 

 thirty minutes. 



In several of the experiments Avhere the conditions of tem- 

 perature and moisture were practically the same, and a large 

 potential was employed, a serious retardation was shown, 

 and in some instances death ensued ; in other cases, where a 

 very small potential was employed, no appreciable accelera- 

 tion was shown. 



From these facts we are led to believe that there is a max- 

 imum, optimum and minimum voltage ; and, from the fact 

 that different potentials were required to stimulate the grow^th 

 of plants of difierent species, — and, in fact, of plants of the 

 same variety and apparently of the same size, — it is evident 

 that the maximum, optimum and minimum potentials vary 

 with different varieties and species of plants, and also with 

 plants of the same variety, depending upon the size, structural 

 ditferentiation, development, etc., of the individual plant. 



SUIMMARY. 



1. Atmospheric ele.ctricity exerts an appreciable influence 

 upon the germination of seeds. 



{(/) It accelerates the processes of germination. (In the 

 experiments tried, those seeds charged with electricity show 

 an acceleration in germination of 55.4 per cent, in fort3'-eight 

 hours, 23.1 per cent, in seventy-two hours, and 17.11 per 

 cent, in ninety-six hours.) 



(i) It does not increase, to an appreciable extent, the 

 total germination of charged seeds over the normal. 



(c) It does not awaken to life seeds which have lost 

 vitality. 



2. Atmospheric electricity has an appreciable influence, 

 upon the growth of plants. 



(a) From the results of these experiments we are led to 

 believe that there is a maximum, optimum and minimum 

 potential, but these have not yet been accurately determined. 



{b) That the maximum, optimum and minimum voltages 

 vary not only with the diflerent varieties or species of plants, 

 but with diff*erent individuals of the same varieties, and 

 S})ecies depending largely upon the size, structural difleren- 

 tiation and degree of development of the plant. 



