The Effect of Temperature 26 The Effect of Food 27 The Effect of Light 29 The Effect of Gravity 30 The Effect of Contact 33 The Effect of Chemical Changes in the Environment 35 General Conclusions 36 CHAPTER III THE INTERNAL FACTORS OF REGENERATION IN ANIMALS Polarity and Heteromorphosis 38 Lateral Regeneration 43 Regeneration from an Oblique Surface 44 The Influence of Internal Organs at the Cut-surface 52 The Influence of the Amount of New Material 54 The Influence of the Old Parts on the New 62 The Influence of the Nucleus on Regeneration 65 The Closing in of Cut-edges 69 CHAPTER IV REGENERATION IN PLANTS Regeneration in Flowering Plants 71 Regeneration in Liverworts, Mosses, and Moulds 84 Hypothesis of Formative Stuffs 88 CHAPTER V REGENERATION AND LIABILITY TO INJURY Examples of Supposed Connection between Regeneration and Liability to Injury 92 Regeneration in Different Parts of the Body 97 Regeneration throughout the Animal Kingdom 103 Regeneration and the Theory of Natural Selection 108 CHAPTER VI REGENERATION OF INTERNAL ORGANS. HYPERTROPHY. ATROPHY Regeneration of Liver, Eye, Kidney, Salivary Glands, Bones, Muscles, Nerves, Brain, and Cord of Vertebrates 111 Examples of Hypertrophy 115 Theories of Hypertrophy 118 Atrophy 123 Incomplete Regeneration 125 CHAPTER VII PHYSIOLOGICAL REGENERATION Supposed Relation between Physiological Regeneration and Restorative Regeneration 128 Regeneration and Growth 131 Double Structures 135 CHAPTER VIII SELF-DIVISION AND REGENERATION. BUDDING AND REGENERATION. AUTOTOMY. THEORIES OF AUTOTOMY