SPECTRAL SENSITIVITY OF PARIETAL EYE OF GREEN IGUANA

The slow photic response of the parietal eye of the Green Iguana consisted of a positive and negative component which were wave-length dependent. The spectral sensitivity curve of the positive component peaked at 460 nm while that of the negative component at 520 nm. The two components responded differently to double flashes; the amplitude of the negative component elicited by a second 560 nm stimulus decreased as the inter-flash interval was decreased while that of the positive component elicited by a 440 nm stimulus increased as the inter-flash interval decreased. The positive component appeared to be a pre-excitatory inhibitory system. © 1969.