TRANSLATIONS OF FOREIGN BIOLOGICAL MEMOIRS IV. ------------------------------------------------------------------------ London _HENRY FROWDE_ OXFORD UNIVERSITY PRESS WAREHOUSE AMEN CORNER, E.C. ------------------------------------------------------------------------ ESSAYS UPON HEREDITY AND KINDRED BIOLOGICAL PROBLEMS BY Dr. AUGUST WEISMANN PROFESSOR IN THE UNIVERSITY OF FREIBURG IN BREISGAU _AUTHORISED TRANSLATION_ EDITED BY EDWARD B. POULTON, M.A., F.L.S., F.G.S. TUTOR OF KEBLE COLLEGE, OXFORD LECTURER IN NATURAL SCIENCE, JESUS COLLEGE, OXFORD SELMAR SCHÖNLAND, Ph.D. SUB-CURATOR OF THE FIELDING HERBARIUM IN THE UNIVERSITY OF OXFORD AND ARTHUR E. SHIPLEY, M.A., F.L.S. FELLOW AND LECTURER OF CHRIST'S COLLEGE, CAMBRIDGE DEMONSTRATOR OF COMPARATIVE ANATOMY IN THE UNIVERSITY OF CAMBRIDGE Oxford AT THE CLARENDON PRESS 1889 ------------------------------------------------------------------------ AUTHOR’S PREFACE. The essays which now appear for the first time in the form of a single volume were not written upon any prearranged plan, but have been published separately at various intervals during the course of the last seven years. Although when writing the earlier essays I was not aware that the others would follow, the whole series is, nevertheless, closely connected together. The questions which each essay seeks to explain have all arisen gradually out of the subjects treated in the first. Reflecting upon the causes which regulate the duration of life in various forms, I was drawn on to the consideration of fresh questions which demanded further research. These considerations and the results of such research form the subject-matter of all the subsequent essays.