Excerpt from The Early Development of Planorbis: A Dissertation The investigation, the results of which are recorded in the present paper, was carried on under the supervision of Prof. C. O. Whitman, at the University of Chicago and at the Marine Biological Laboratory at Woods Holl, Mass. It is a source of gratification to acknowledge the generous treatment I have received in both these places at Professor Whitman's hands. I wish also to express my appreciation of the many suggestions I have received from Dr. E. G. Conklin, both in person and through his admirable paper on the Embryology Of Crepidula. 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.