THE EVOLUTION THEORY VOLUME II THE EVOLUTION THEORY BY DR. AUGUST WEISMANN PROFESSOR OF ZOOLOGY IN THE UNIVERSITY OF FREIBURG IN BREISGAU TRANSLATED WITH THE AUTHOR'S CO-OPERATION BY J. ARTHUR THOMSON REGIUS PROFESSOR OF NATURAL HISTORY IN THE UNIVERSITY OF ABERDEEN AND MARGARET R. THOMSON ILLUSTRATED IN TWO VOLUMES VOL. II LONDON EDWARD ARNOLD 41 & 43 MADDOX STREET, BOND STREET, W. 1904 _All rights reserved_ CONTENTS LECTURE PAGE XX. REGENERATION 1 XXI. REGENERATION (_continued_) 23 XXII. SHARE OF THE PARENTS IN THE BUILDING UP OF THE OFFSPRING 37 XXIII. EXAMINATION OF THE HYPOTHESIS OF THE TRANSMISSIBILITY OF FUNCTIONAL MODIFICATIONS 62 XXIV. OBJECTIONS TO THE THESIS THAT FUNCTIONAL MODIFICATIONS ARE NOT TRANSMITTED 80 XXV. GERMINAL SELECTION 113 XXVI. GERMINAL SELECTION (_continued_) 136 XXVII. THE BIOGENETIC LAW 159 XXVIII. THE GENERAL SIGNIFICANCE OF AMPHIMIXIS 192 XXIX. THE GENERAL SIGNIFICANCE OF AMPHIMIXIS (_continued_) 210 XXX. IN-BREEDING, PARTHENOGENESIS, ASEXUAL REPRODUCTION, AND THEIR CONSEQUENCES 238 XXXI. THE INFLUENCES OF ENVIRONMENT 265 XXXII. INFLUENCE OF ISOLATION ON THE FORMATION OF SPECIES 280 XXXIII. ORIGIN OF THE SPECIFIC TYPE 299 XXXIV. ORIGIN OF THE SPECIFIC TYPE (_continued_) 330 XXXV. THE ORIGIN AND THE EXTINCTION OF SPECIES 346 XXXVI. SPONTANEOUS GENERATION AND EVOLUTION: CONCLUSION 364 INDEX 397 LIST OF ILLUSTRATIONS FIGURE PAGE 35 _B_ (repeated). _Hydra viridis_, the Green Freshwater Polyp. 4 96. A Planarian cut transversely into nine pieces 6