Excerpt from The Voyage of H. M. S. Challenger, Vol. 31: Zoology; Report on the Alcyonaria Collected by H. M. S. Challenger During the Years 1873-76 A natural classification of a group should no doubt be the record of its evolution, and should exhibit at a glance the stages through which the varied forms passed on their way to the attainment of their present positions. A very thorough knowledge of the life history of existing forms, and of the measure of their variableness, would be necessary ere the outlines of such a classification could be attempted, and for the filling in of the details one would require also a knowledge of extinct forms. Unfortunately for the perfection of such a scheme among the Alcyonaria there is no appeal to palaeontology, the phenomena which are of most importance, - such as the structure and relations of the canal system, the structure and development of the individual polyp forms, - can never in fossil forms be known, owing to their being incapable of preservation in tables of stone. 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.