Electro-physiology electrophysiolog02bied Year: 1896-98 VI ELECTROMOTIVE ACTION IN VEGETABLE CELLS approximately recovered its former strength. The same reaction occurred in seedlings of Pisxm sativum on leading off from the collar of the root and the stem, where Hermann (3) had pre- viously found a normal strong current, the root being negative to the body ( the cotyledons). The often exceeded ^ Dan. Johannes Miiller-Hettlingen (3), who studied this effect more closely at Hermann's request, formulated the law as follows : When one of the leading-off electrodes is persistently app
Electro-physiology electrophysiolog02bied Year: 1896-98 VI ELECTROMOTIVE ACTION IN VEGETABLE CELLS approximately recovered its former strength. The same reaction occurred in seedlings of Pisxm sativum on leading off from the collar of the root and the stem, where Hermann (3) had pre- viously found a normal strong current, the root being negative to the body ( the cotyledons). The often exceeded ^ Dan. Johannes Miiller-Hettlingen (3), who studied this effect more closely at Hermann's request, formulated the law as follows : When one of the leading-off electrodes is persistently applied to the cotyledons, while the other leads off successively from points of the seedling above or below the cotyledon, there is always a current directed from the electro-positive seed husk, or cotyledon, FIG. 138. to all other electro-negative parts of the seedling, its being less in proportion as the exploring electrode is nearer the cotyledon, above or below it. Fig. 138 gives a schema of this reaction. Haake occasionally found reversal, or augmentation, instead of diminution, of the original current when respiration was inter- rupted. ' Such parts of plants as naturally exhibit marked differences in respiration yield excessively strong currents, the reproductive organs of flowers, on leading off from pistil or anther, and flower-stalk.' In such cases Haake obtained deflec- tions of 50—80 degrees on the capillary electrometer, while in green leaves the total effect is only 15-20 degrees. The is also, comparatively speaking, very marked when the respiration of a plant is checked at one electrode only, by cutting off' the supply of oxygen, which Haake effected by en- closing seedlings of Pisum or Faba in a double tube, and replacing the air by hydrogen on one side only (Fig. 137). In one speci-
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