Contents ix 

 PART III: 



THE ACTION OF THE GENETIC MATERIAL 



1. Introduction 246 



2. A Generalized Example 251 



3. Phenocopy and Norm of Reaction 255 



A. Norm of Reaction 255 



B. Phenocopy and Mutation 256 



C. Chemical Phenocopies 262 



4. Primary Actions 267 



A. The Chromosomal Site 267 



B. The Intranuclear Site 275 



C. Special Theories of Genie Action 279 



a. The One Gene — One Action Theory 279 



b. Relation to Other Ideas 282 



5. Genie Control of Development 287 



A. The Qualitative Aspect 289 



a. Nuclear versus Cytoplasmic Differentiation 289 



b. Biochemical Attack 305 



B. The Cytoplasmic Substrate of Genie Action 311 



a. Basic Deliberations 312 



b. Specific Ideas Derived from Embryology 314 



c. Activation of the Genes 320 



C. Kinetics of Genie Action 333 



a. Dosage of Genie Material 335 

 aa. Dosage in Sex Determination 335 

 bb. Dosage within Allelism 341 

 cc. Dosage in Sex Linkage 356 

 dd. Multiple Factors and Dosage 360 



b. Dominance, Potency, Penetrance 363 



c. Dosage via Chromosomes 383 



D. Genie Action in Four Dimensions 384 



a. Factorial Collaboration 385 



b. Pleiotropy 393 



c. The Time Dimension 400 



d. Short Cuts: Inductors, Hormones 402 



e. Mutational Changes of Determination; Regulation and 

 Integration 409 



E. Synopsis 418 



PART IV: 



GENETICS OF SEX DETERMINATION 



1. Introduction 424 



2. Primary Genetic Possibilities 426 



