抄録
1. The various factors, i.e., pre-adaptation, stimulus intensity, stimu-lus area of retina, which are necessary for the appearance of the critical stage (dark adaptation) of perception time by white light stimulus, have been systematically pursued.
2. The critical stage is retarded and much more manifest when the light adaptation is sufficiently strong in intensity.
3. It is necessary to, have an appropriate stimulus intensity for the appearance of the critical stage of perception time. This lower extreme is found in the threshold value of the cone of the dark adapted eye, and its upper extreme is found in the region nearest the maximum stimulus in-tensity relative to the perception time of dark adapted eye. It does not appear outside of the above mentioned range. That is, in the 5° peripheral, it is most appropriate within the range, 3.4×10-4 Stilb, to 4.1×10-1 Stilb. The above is found to be in accord with the reports of Fröhlich and the others.
4. The critical stage of perception time in the peripheral vision is evident in appearance, but not quite evident in the foveal vision. This is not in accord with the results of Vogelsang.
5. The critical stage of perception time, is interpreted as becoming-evident in appearance when both the cone and rod are subject to appro-priate stimulations.
