IV CONTENTS. 



PAGE. 



II. The Second Chromosome Group of Mutant Characters — continued. 



Black 144 



Balloon .' 148 



Vestigial 150 



Blistered 155 



The Semi-Dominance of Blistered — Free-Vein 158 



Jaunty ■. 160 



A Mutating Period for Jaunty 161 



Curved 164 



Purple 169 



The Differentiation of Purple by Vermilion — Disproportional Modification . 170 



No Crossing Over in the Male 174 



The Inviability of Vestigial — Prematuration, Repugnance, Lethals 177 



The Purple " Epidemic"—" Mutating Periods" 178 



Balanced Inviability, Complementary Crosses 181 



The Variation of Crossing Over with Age 183 



Coincidence 188 



The Relation between Coincidence and Map Distance 188 



Special Problems Involving Purple — Age- Variations, Coincidence, Tempera- 

 ture-Variations, Cross-Over Mutations, Progeny Test for Crossing-Over 193 



Strap 200 



Arc 202 



Gap 208 



Antlered 211 



Dachs 216 



Streak 222 



Dominance and Lethal Effect of Streak, Parallel to Yellow Mouse 223 



Comma 228 



Morula 230 



Female Sterility of Morula 230 



Apterous • 236 



Cm and Ciir 239 



Cream 11 239 



Trefoil 244 



Cream b 245 



Pinkish 247 



The Double-Mating Method 248 



Plexus 251 



Limited 254 



Confluent 255 



Confluent Virilis 257 



Fringed 257 



Star 259 



Lethal Nature of the Homozygous Star 260 



Crossing Over in the Male 263 



Nick 273 



Vestigial-Nick Compound 275 



Dachs-Lethal 277 



Dachs-Deficiency? 278 



Balanced Lethals 279 



Squat 283 



Lethal Ila 286 



Telescope 291 



Second Chromosome Modifiers for Dichaite Bristle Number 293 



Dachsoid 294 



The Construction of the Map of the Second Chromosome 297 



Summary of Available Data on Crossing Over in the Second Chromosome 298 



Constructional Map 302 



Working and Valuation Map 303 



Bibliography 304 



