36 HATCH EXPERIMENT STATION. [Jan. 



of these experiments the latent period varied from fifteen to 

 thirty minutes. 



In several of the experiments where the conditions of tem- 

 peratm^-e 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 emplo3^ed, no appreciable accelera- 

 tion was shown. 



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

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

 that different potentials were required to stimulate the growth 

 of plants of different 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 

 diff'erentiation, development, etc., of the individual plant. 



SmviMARY. 



1. Atmospheric electricity 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 percent, in forty-eight 

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

 cent, in ninety-six hours.) 



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

 total orormination of char<jed seeds over the normal. 



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

 vitalitv. 



2. Atmospheric electricit}^ has an appreciable influence 

 upon the growth of plants. 



(ff) 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 accm-ately determined. 



(6) That the maximum, optimum and minimum voltages 

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

 but with different individuals of the same varieties, and 

 species depending largely upon the size, structural differen- 

 tiation and degree of development of the plant. 



