CONTENTS
Action of environment on plant—Revelation of internal condition by character of response—Problems to be solved—Electrical response—Mechanical response—Motile organ in Mimosa pudica—Response in plant and animal—Different phases of the responsive movement—Graphic record—Determination of absolute movement of leaf and its time-relations—Characteristic effects of different agencies on the response-curve—Specific difficulties in recording plant-response • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
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THE RESONANT RECORDER
Advantages of intermittent contact in record—Two types of apparatus: the Oscillating Recorder, and the Resonant Recorder—Coercer and Vibrator—Perfect tuning—Recorders with standardised frequencies—Slide and clockwork—The record its own chronogram—Smoked surface and its fixation—Adjustments of the writer—Records with continuous and intermittent contacts • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
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METHODS OF STIMULATION
Different methods of stimulating the plant: mechanical, chemical, thermal and electrical—Difficulties of securing quantitative stimuli—Direct and indirect stimulation—Ideal modes of stimulation—Electro-thermic stimulation—Stimulation by constant current—Stimulation by condenser-discharge—Non-polarisable electrodes—Direct, extra-electrodal, and intra-electrodal stimulation—Stimulation by induction-shock—Effects of make- and break-shock—Excitation by tetanising shock • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
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