The evolutionist Ernst Mayr considered August Weismann “one of the great biologists of all time.” Yet the man who formulated the germ plasm theory—that inheritance is transmitted solely through the nuclei of the egg and sperm cells—has not received an in-depth historical examination. August Weismann reintroduces readers to a towering figure in the life sciences. In this first full-length biography, Frederick Churchill situates Weismann in the swirling intellectual currents of his era and demonstrates how his work paved the way for the modern synthesis of genetics and evolution in the twentieth century. In 1859 Darwin’s tantalizing new idea stirred up a great deal of activity and turmoil in the scientific world, to a large extent because the underlying biological mechanisms of evolution through natural selection had not yet been worked out. Weismann’s achievement was to unite natural history, embryology, and cell biology under the capacious dome of evolutionary theory. In his major work on the germ plasm (1892), which established the material basis of heredity in the “germ cells,” Weismann delivered a crushing blow to Lamarck’s concept of the inheritance of acquired traits. In this deeply researched biography, Churchill explains the development of Weismann’s pioneering work based on cytology and embryology and opens up an expanded history of biology from 1859 to 1914. August Weismann is sure to become the definitive account of an extraordinary life and career.

Excerpt from The Germ-Plasm: A Theory of Heredity In preparing the English edition of the present work, I have had the great advantage of being able to consult Professor Weismann personally with regard to many of the more difficult passages. Only those who have attempted to make a translation of an abstruse work from German manuscript, can appreciate the difficulties of rendering such a work into good English, and at the same time of keeping closely to the text. As the time in which the translation had to be prepared was a comparatively short one. I have been unable to revise the style as thoroughly as I could have wished, but trust that the author's meaning has been expressed with tolerable accuracy. In the case of special technical terms which have no recognised English equivalents, I have in all cases added the German word in brackets the first time they are used. For the extremely useful and untranslateable word 'Anlage,' the somewhat awkward term 'primary constituent' has been used when it refers to the concrete vital units: in other cases, it has been rendered by 'rudiment;' or, when it has a more abstract meaning, by 'predisposition.' The words 'Eigenschaft,' 'Charakter,' 'Merkmal,' and 'Qualität,' are often used synonymously by the author, and have therefore been indiscriminately translated by 'characteristic,' 'character,' 'peculiarity,' and 'quality.' I must express my thanks to Dr. G. H. Parker, of Harvard University, Cambridge, Mass., who kindly undertook a first revision of Chapters XIII. and XIV., and thereby rendered an earlier publication of the book possible; as well as to my friend and colleague Mr. Franck Arnold, for help in elucidating some of the more complicated sentences, and for many suggestions. 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.