Abstract
The rod-response was isolated from the cone-responses by the method of electrostimulation, and the effect of intensities of light was investigated upon the spectral distribution curves of rod-response obtained at various parts of the retina.
1. The maxima of all curves were found at the same spectral region as that of the scotopic visibility curve, that is, at about 510mμ.
2. Even when the intensity of light was raised to such a high level that the eye became surely photopic, the maxima of the curves did not show any shift. In other words, the rod response curves show no Purkinje shift.
3. The curves obtained at lower intensities were smooth and coincided well with the scotopic visibility curve by a simple correction, but some irregularities were found on the curves obtained from parafoveal areas at high intensities.
4. The magnitude of rod-response increased with increasing intensities of light, but was depressed above a certain intensity. This fact and the notches on the rod response curves obtained with spectral lights of high intensities were ascribed to an inhibitory action of cones upon rods.
Prof. K. Motokawa furnished guidance and helpful criticism, for which we express here hearty thanks.
