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102 the animal nerve; it has also been shown that the effects of various physical and chemical agents are the same in the conducting tissues of plant and of animal.

Effect of application of glycerine: Experiment 35.—It is known that desiccation, generally speaking, enhances the excitability of the animal nerve. As glycerine, by absorption of water, causes partial desiccation, I tried its effect on conduction of excitation in the petiole of Mimosa. Enhancement of conducting power may be exhibited in two ways: first, by an increase of velocity of transmission; and, secondly, by an enhancement of the intensity of the transmitted excitation, which would give rise to a greater amplitude of response of the motile indicator. In Fig. 41 are given two records, N, before, and the other after

41.—Action of glycerine in enhancing the speed and intensity of transmitted excitation. Stimulus applied at the vertical line. Successive dots in record are at intervals of 0.1 sec.

the application of glycerine on a length of petiole through which excitation was being transmitted. The time-records demonstrate conclusively the enhanced rate of transmission after the application of glycerine. The increased intensity of transmitted excitation is also seen in the enhanced