Induction of Water Drive in Triturus viridescens With Anterior Pituitary Extract. ∗

Abstract

In certain well established localities the American newt, Triturus viridescens, shows two well-defined habitats in its life cycle. The larval and adult phases live in water while the immature phase, representing some 3 to 5 years of the cycle, lives on land. In this interesting life-cycle 2 migrations occur, that from water to land following metamorphosis and that from land to water as maturity is reached. In an attempt to determine whether or not these migrations—particularly that from land to water—-are brought about by the endocrine glands Reinke and Chadwick 1 were able to induce the land phases to assume a water habitat, long before they would do so normally, by giving them intramuscular implants of pituitaries from the adults. By appropriate tests the water drive-inducing factor was shown to be a product of the anterior lobe of the pituitary. They were able to show later that this action of the pituitary occurs in the absence of both the thyroids and gonads. 2

Is the factor which induces the water drive peculiar to Triturus, or is it a hormone distributed widely among the vertebrates but with a specific effect in Triturus? If generally present in the vertebrates, with what known pituitary principles is it to be identified? The nature of its effect in Triturus is such that one is led to believe that the same pituitary principle which is responsible for growth in the body generally also induces migration to water as maturity is reached. In order to test the presence of the water drive factor in at least one other vertebrate class and at the same time to test the growth hormone as possibly being the cause of it, an attempt has been made to induce the water drive with a commercial extract of sheep pituitary which contains the growth-promoting factor (Antuitrin G).