Spectral Sensitivity in the Turtle

Abstract

The height of the b-wave in the electroretinogram of the turtle Pseudemys was used as an index of spectral sensitivity under conditions of light and dark adaptation. A series of discontinuous wavelengths of equal energy was used as stimuli. The peak scotopic sensitivity occurred in the region of 559 μ while the maximal sensitivity under photopic conditions occurred at approximately 658 μ. Although the present methods do not allow a precise localization of the peaks of these two visual functions, the values are accurate within approximately 15 μ either side of the stated peaks.