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Igog] STON E—ELECTRICITY AND MICROORGANISMS 379 
Many theories, however, in regard to the cause of the stimulating 
effect of electricity on plant growth have been advanced, some of 
which are hardly worthy of consideration, since they fail to meet the 
requirements of experiments, and we will not enter into a discussion 
of them here. 
Electricity, like other forms of stimulation, such as light, heat, etc., 
undoubtedly affects the protoplasm of the plant, which causes certain 
metabolic processes to become active and accelerated growth results. 
In plants showing circulation and rotation of protoplasm, e. g., Chara, 
Nitella, etc., feeble electrical currents induce a more rapid streaming 
of the protoplasm, which is undoubtedly associated with greater 
metabolic activity, and it is not at all unlikely that changes of a similar 
nature take place in other organisms when subject to feeble electrical 
currents. 
AMHERST, Mass. 
