Parietalectomy does not affect testicular growth in photoregulating lizards.

The testicular response of male anoles maintained at a constant 32 degrees C was similar in both parietalectomized and sham-parietalectomized lizards exposed to either constant light (40 lux intensity) or to photic gradients (40-300 lux). The results support the hypothesis that the acceleration of gonadal growth in parietalectomized lizards noted by others depends on the ability of lizards to self-regulate exposure to thermal, but not photic, stimuli.