Contents 



3. Different Genetic Possibilities within the Balance Theory 432 



A. Variants in Regard to Sex Determiners 432 



B. Variants within the Balance System 433 



a. Female Heterogamety 433 



b. Male Heterogamety 435 



c. The Melandrium Case 437 



d. Dioecism Derived from Monoecism in Other Cases 444 



e. Once More the Y-Chromosome 446 



4. Balance and Modification 448 



5. Monoecism and Intersexuality 451 



A. Introduction 451 



B. Shift of Sex Expression in Maize 452 



C. Monoecism and Intersexuality in Streptocarpus 453 



D. The Embryological Side of the Problem 457 



6. Different Types of Sex Determination 461 



A. So-called Phenotypic Sex Determination 461 



B. Multifactorial Sex Determination? 466 



C. Sex in Haploids 469 



D. The Hymenoptera Type 473 



PART V: 



GENETIC THEORY AND EVOLUTION 



1. Introduction 478 



2. Evolution of the Genie Material 482 



3. Evolution and Genie Action 489 



BIBLIOGRAPHY 494 



INDEX OF AUTHORS 547 



SUBJEGT INDEX 



