CONTENTS 



INTRODUCTION 



PAGE 



A. — HISTORICAL PART i 



B. — DESCRIPTIVE PART ... . . .20 



PART I.— THE MATERIAL BASIS OF HEREDITY 



CHAPTER I 



The Germ-Plasm — 



1. The fundamental units ....... 37 



2. The control of the cell ....... 45 



3. The determinants ........ 53 



4. The id in ontogeny ........ 60 



5. Summary of sections 1-4, relating to the structure of the 



germ-plasm . . -75 



6. The mechanism for the phyletic changes in the germ- 



plasm . ......... 77 



7. The magnitude of the constituents of the germ-plasm . 85 



PART II. — HEREDITY IN ITS RELATION TO 

 MONOGONIC REPRODUCTION 



CHAPTER II 

 Regeneration — 



1. Its cause and origin in the idoplasm • • • • 93 



2. The phylogeny of regeneration . . . . .114 



3. Facultative or polygenetic regeneration . . . .126 



4. Regeneration in plants . . . . . . .132 



5. Regeneration in animal embryos, and the principles of 



ontogeny . . , ' , . . . . -134 



xix 



