X 



TABLE OF CONTENTS 



Chapter VII. The Chromosomes in Heredity : Mechanical 



1. The Chromosome Theory of Heredity . 



2. Segregation ...... 



3. The Theory of Crossing-over 



4. Cytological Evidence of Crossing-over 



5. Crossing-over in Structural Hybrids 



6. The Parallel Investigation of Crossing-over . 



Chapter VIII. The Chromosomes in Heredity : Physiological 



The Two Methods of Enquiry 

 Differentiation of Behaviour in the Cell 

 Balance ...... 



Inert Chromosomes and Genes . 



The Gene ..... 



244 

 247 

 249 



254 

 260 

 281 



302 

 303 

 315 

 329 

 332 



Chapter IX. Permanent Hybrids 



1 . Prior Conditions 



2. Complex Heterozygotes : (Enothera 



3. Sex Heterozygotes 



335 

 338 

 356 



Chapter X. The Breakdown of the Genetic System : Adventitious 



1 . The Breakdown of Mitosis 



2 . The Breakdown of Meiosis 



3. The Effects of Structural Change 



395 

 399 

 419 



Chapter XI. The Breakdown of the Genetic System : Controlled 



1. Definition and Classification 



2. Apomixis in Relation to the Life Cycle 



3. Non-Recurrent Apomixis . 



4. Meiosis in Relation to Parthenogenesis 



5. The Origin of Apomixis in Experiment 



6. Replacement of Sexual Reproduction . 



Chapter XII. Cell Mechanics 



1. Introducing an Axiomatic .... 



2. The Internal Mechanics of the Chromosomes 



3. The External Mechanics of the Chromosomes 



4. Ultra-Mechanics ..... 



Appendices 



I. Interpretation 



II. Technique 



III. Glossary . 



IV. Bibliography 



434 

 435 



442 



451 

 464 

 470 



479 

 483 

 492 



547 



563 

 569 

 572 

 584 



Index 



648 



