The Modification by Temperature of the Photoperiodic Control of Gonadal Development in the Lizard Xantusia vigilis

Abstract

KNOWLEDGE of the role of environmental factors in the timing of reptilian reproduction is fragmentary and inconclusive. Nevertheless, some reptiles lend themselves readily to the kinds of investigation of this topic which have been extensively carried out on birds and mammals. In a previous study (Bartholomew, 1950) it was shown that increased length of day is more important than increased temperature in accelerating the gonadal growth of Xantusia vigilis, a small ovoviviparous lizard found in the deserts of southwestern United States and northern Mexico. The present experiments 45