EXPERIMENTAL ALTERATION OF THE AXIAL GRADIENT IN THE ALGA, GRIFFITHSIA BORNETIANA
暂无分享,去创建一个
1. The original axial susceptibility gradient of the alga Griffithsia is more or less completely obliterated or reversed after one or two days of confinement in a small volume of water, and the larger the volume of living plant protoplasm introduced, the more rapid the changes.2. Where the conditions of confinement are extreme, obliteration or reversal of the gradient is followed in one or two days by death with a basipetal gradient, but under less extreme conditions the alteration of the gradient is followed by the separation of the axis into individual cells or occasionally small cell groups, the separation beginning apically and progressing basipetally.3. Obliteration or reversal of the original axial gradient, followed by cell separation occurs, though more slowly, when the plants are kept in open standing water and to a greater or less degree, but still more slowly, in slowly running water in diffuse daylight.4. A variable percentage of the isolated cells dies, the death rate being in general highest...