Produced by Larry B. Harrison, Bryan Ness, Chuck Greif and the Online Distributed Proofreading Team at http://www.pgdp.net (This file was produced from images generously made available by The Internet Archive) REGENERATION Columbia University Biological Series. EDITED BY HENRY FAIRFIELD OSBORN AND EDMUND B. WILSON. 1. FROM THE GREEKS TO DARWIN. By Henry Fairfield Osborn, Sc.D. Princeton. 2. AMPHIOXUS AND THE ANCESTRY OF THE VERTEBRATES. By Arthur Willey, B.Sc. London Univ. 3. FISHES, LIVING AND FOSSIL. An Introductory Study. By Bashford Dean, Ph.D. Columbia. 4. THE CELL IN DEVELOPMENT AND INHERITANCE. By Edmund B. Wilson, Ph.D. J.H.U. 5. THE FOUNDATIONS OF ZOOLOGY. By William Keith Brooks, Ph.D. Harv., LL.D. Williams. 6. THE PROTOZOA. By Gary N. Calkins, Ph.D. Columbia. 7. REGENERATION. By Thomas Hunt Morgan, Ph.D. _COLUMBIA UNIVERSITY BIOLOGICAL SERIES. VII._ REGENERATION BY THOMAS HUNT MORGAN, PH.D. PROFESSOR OF BIOLOGY, BRYN MAWR COLLEGE [Illustration] New York THE MACMILLAN COMPANY LONDON: MACMILLAN & CO., LTD. 1901 _All rights reserved_ COPYRIGHT, 1901, BY THE MACMILLAN COMPANY. _Norwood Press J. S. Cushing & Co.--Berwick & Smith Norwood, Mass., U.S.A._ To My Mother PREFACE This volume is the outcome of a course of five lectures on “Regeneration and Experimental Embryology,” given in Columbia University in January, 1900. The subjects dealt with in the lectures are here more fully treated and are supplemented by the discussion of a number of related topics. During the last few years the problems connected with the regeneration of organisms have interested a large number of biologists, and much new work has been done in this field; especially in connection with the regenerative phenomena of the egg and early embryo. The development of isolated cells or blastomeres has, for instance, aroused widespread interest. It has become clearer, as new discoveries have been made, that the latter phenomena are only special cases of the general phenomena of regeneration in organisms, so that the results have been treated from this point of view in the present volume.