Excerpt from A Text-Book of Zoology, Vol. 1 of 2 The various Sections have been written by the authors in fairly equal proportions, but the work of each has been carefully read and criticised by the other, and no disputed point has been allowed to stand without thorough discussion. We are therefore jointly and severally responsible for the whole work. 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.