A. B. Plowman — Electromotive Force in Plants. 97 



5. Extremely slight electrical shock does not appreciably 

 disturb the degree of dissociation of a solution, and so does not 

 increase its conductivity. But many experiments show that 

 even almost imperceptible shock stimulates protoplasmic activ- 

 ity to a marked degree. In the leaf this increased activity 

 would naturally be more pronounced in the part already active 

 than in that which is comparatively passive. 



6. The question of the nature of the transfer of impulses 

 through living protoplasm must remain properly a biological 

 problem until the mechanism of protoplasm itself is more fully 

 understood. That the transfer of an impulse is attended by 



Fig. 1. 



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