CONTENTS vii 

 PART I. THE DIFFERENTIATION OF CELLS AND OF ORGANS 



rACiE 



40. General ............. .138 



41. On Formative Induction and the Inherent Peculiarities of Cells and Organs . 141 



42. Formative Induction (continued) ......... 145 



43. The Induction of Dorsiventrality 149 



44. Polarity. . 154 



PART II. CORRELATION AND REPRODUCTION 



45. General .............. 161 



46. Correlation 164 



47. Reproduction and Regeneration 167 



PART III. SYMBIOTIC REACTIONS 



48. Changes of Shape due to Symbiotic Interaction 170 



49. Grafting and Graft-hybrids 173 



50. Details concerning Symbiotic Unions and Interactions 176 



PART IV. REVIEW OF THE INTERNAL FACTORS DETERMINING SPECIFIC SHAPE 



51. General . . 179 



52. The Transference of Stimuli 181 



53. (continued] 185 



PART V. HYPOTHESES OF ULTIMATE STRUCTURE AND HEREDITY 



54. Theoretical 186 



CHAPTER VIII 



VARIATION AND HEREDITY 



55. The Internal Conditions for Hereditary Variation 189 



56. Facts concerning Variation * 191 



CHAPTER IX 



PERIODICITY OF GROWTH 



57. General ... 197 



58. The Daily Periodicity of Growth . 200 



59. The Yearly Periodicity 204 



60. The Influence of the External Conditions upon the Yearly Periodicity . . 209 



61. The Origin of Yearly Periodicity . 212 



62. Abscission and Leaf-fall 216 



CHAPTER X 



THE POWER OF RESISTANCE TO EXTREMES 



PART I. THE CAUSES OF DEATH 



63. Death and Dormancy 219 



64. Death and Senile Decay -221 



