ABSTRACT
The present paper is an account of experiments carried out under the direction of Professor Julian S. Huxley, in April and May, 1927, in an attempt to amplify and extend similar experiments done by the latter in the spring of 1926 (Huxley, 1926). The object of these experiments was to ascertain what effects a steep apico-basal temperature gradient has on the developing frog’s egg. The present experiments were carried out on a larger scale, their range being widened to include the effects of both apico-basal and lateral temperature gradients on later embryonic stages. The apparatus was improved, making it possible to use a steeper temperature gradient and so obtain more striking results. Some of the results have been embodied in a general paper (Huxley, 1927).
