On the duality of light stimulation.

[摘要] The questions of photoperiodism and light inhibition have provoked much discussion among physiologists. In order to dispose of these vexed problem of long standing, we must grasp firmly the conception of light effects. In this paper we made an effort to treat this tangled question from an entirely new angle, and to investigate the phenomena from the electro-physiological side. The results obtained were the following: 1. Studying the light effects upon actinomyces it was found that the specific effects cf wave length were obtained at different intensities. 2. Irradiation with short wave light caused negative electromotivo force while red light produced the potential change of opposite sign. With regard to the so-called excitement, the blue light has the most sensitive property. 3. As seen from figures presented above, actinomyces showed also significant responses after cessation of red light at low intensities of light. The color reactions are not independent, but exert some influence on each other. 4. We found that this off-effects were produced by release from counter-action motivated by long and short wave light with varying its intensities. This finding may be valuable contribution the crop physiology. 5. Analogous phenomena were observed among several plants. Which may probably conceal some of multiple excitements. Such complex phenomena of light inhibition in the crop may be also interpreted in terms of certain interaction taking place in the tissues stimulated by light. From our results we could enter upon the theoretical phases of the problem of light stimulation. As yet we have done no more than touch this subject.

[学科分类] 农业科学（综合）