EFFECT OF STRONG STIMULATION 187 



frequency electric field was found to initiate growth, which 

 persisted for a considerable length of time (fig. io8a). 



Experiment 113. Effect of 'strong stimulation. — I next 

 took another seedling of Wheat which exhibited a more 

 active rate of growth, of 0-5 \x per second. The effective 

 intensity of stimulation was increased by enclosing the 

 plant within a spiral, as in the experiment with Mimosa. 

 The result was a marked retardation of growth exhibited 



Fig. io8a. Revival of growth in Wheat-seedling^ in 

 condition of standstill. 



Normal record, without balance. 



by the down-curve, the balance being upset within 30 seconds 

 of the incidence of stimulus (fig. 109). The results prove 

 that the effect of high-tension alternating current on growth is 

 determined by the intensity of stimulation, and by the tonic 

 condition of the plant. A subtonic organ under feeble 

 stimulation exhibits, in general, acceleration of growth, 

 while an actively growing organ under strong stimulation 

 shows retardation. These characteristics are such as have 

 been found under other modes of stimulation. 



The effects of high-tension alternating current on growth, 

 as noticed by different observers, have been found to be 

 very contradictory. The facts described above on the 



