FERTILITY AND STERILITY IN DROSOPHILA 

 AMPELOPHILA 



II. FERTILITY IN DROSOPHILA AND ITS BEHAVIOR IN 

 HEREDITY 



ROSCOE R. HYDE 



From the Zoological Laboratory, Columbia University 



NINE FIGURES 



CONTENTS 



Introduction 173 



History of the low-producing truncate and the high-producing inbred stocks 175 

 Crosses between the low-producing truncate stock and the high-producing 



wild stocks 176 



Fertility of the Fi and F2 generations from the crosses between the low-pro- 

 ducing truncates and the high-producing wild stocks as determined by 



breeding the animals together in pairs *, 182 



Crosses between the low-producing truncates and the high-producing wild 



stocks in which an exact measure of fertility is employed 185 



Back crosses between the hybrids and the recessive low-producing truncates 194 



Fertility and high productivity of the hybrids 203 



Fertility of .the long-winged brothers and sisters of the truncates 206 



Behavior of the truncate wing in heredity 209 



Sex-ratio 211 



Literature cited 212 



INTRODUCTION 



The first study demonstrated that the sterihty there dealt 

 with is due to some defect probably in the oviduct of the female 

 that prevents her from laying eggs. Since this defect is trans- 

 mitted by males and heterozygous females, the defect when once 

 in a strain constantly recurs. It is evident that this kind of 

 sterility in the female is an entirely different thing from infertility 

 in the sense that eggs laid are not fertilized or if fertilized do not 

 develop. 



It is evident from Part I that the low fertility of the truncate 

 stock would not be explained by the presence of the sterile indi- 

 viduals for after sterility had been practically eliminated the 



173 



THE JOURNAL OS EXPERIMENTAL ZOOLOGY, VOL. 17, NO. 2 

 AUGUST, 1914 



