Excerpt from The Physiology of the Circulation in Plants in the Lower Animals, and in Man: Being a Course of Lectures Delivered at Surgeons' Hall to the President, Fellows, Etc, of the Royal College of Surgeons of Edinburgh, in the Summer of 1872In the fish a heart, consisting of two cavities, is found. In the serpent those cavities are increased to three and in birds and mammals to four.About the PublisherForgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.comThis 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.