Excerpt from History of British Reptiles The Reptilia constitute a class of vertebrated animals of which the structural characters are as follow: - They have cold blood, - that is to say, their power of producing animal heat is so limited as scarcely to be appreciable, and not sufficient, therefore, to keep up any standard temperature of the body, nor to prevent it from following all the thermal variations of the atmosphere or water by which they are surrounded. The integument is covered with hard and dry cuticle in various modifications of form, in some constituting broad plates, in others imbricated scales. The heart is in all cases trilocular, - that is to say, it is composed of two auricles and a single ventricle; the respiration is exclusively pulmonary throughout life, and their reproduction is oviparous. The Amphibia, or Batrachia, which are included in the Reptilia by Cuvier and many other naturalists, differ from them, however, in various essential and important characters. The heart particularly is bilocular: the integument is naked, and the respiration is carried on by means of branchiae during the earlier period of life, changing - in some totally, and in others particularly - to the pulmonary character in the adult condition. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works."