AUTHOR S ABSTRACT OF THIS PAPER ISSUED 

 BY THE BIBLIOGRAPHIC SERVICE, MARCH 31 



THE GENETICS OF PURPLE EYE COLOR IN 

 DROSOPHILA 



CALVIN B. BRIDGES 



Columbia University, New York City 



CONTENTS 



Introduction 265 



Origin 266 



Inheritance 266 



Description 267 



The differentiation of purple by vermilion — disproportionate modification. . . 268 



The relation of purple to pink 269 



The linkage of purple and vestigial 269 



Back cross tests of males, purple vestigial 'coupling' 269 



Back cross tests of females, purple vestigial 'coupling' 270 



No crossing over in the male 273 



Mutations 275 



The inviability of vestigial — prematuration, repugnance, lethals 276 



The purple 'epidemic,' 'mutating periods' 278 



Repetition of the purple vestigial back-cross tests 279 



Balanced inviabilty- — complementary crosses 281 



The variations of crossing over with age 285 



The locus of purple, a two-point map 285 



A three-point map 286 



A three-point back cross, black purple vestigial with balanced inviability. . . 288 



Coincidence 291 



The relation between coincidence and map distance 292 



The use of purple in mapping other genes, curved, streak, etc 292 



Alternated back crosses 295 



A summary of the linkage data involving purple 296 



Special problems involving purple — age variations, coincidence, temperature 



variations, crossover mutations, progeny test for crossing over 297 



Summary and valuation 302 



Literature cited , 305 



INTRODUCTION 



Of the two hundred or more mutations of Drosophila, 'purple' 

 ranks high among those that have proved especially useful because 

 of their ease of identification or other excellent characteristics, and 



265 



THE JOURNAL OF EXPERIMENTAL ZOOLOGY, VOL. 28, NO. 2 



