FERTILITY AND STERILITY IN DROSOPHILA 

 AMPELOPHILA 



III. EFFECTS OF CROSSING ON FERTILITY IN DROSOPHILA^ 



ROSCOE R. HYDE 



Department of Zoology, Columbia University 



ONE DIAGRAM 



CONTENTS 



PART III. Effects of crossing on fertility in drosophila 



Introduction 344 



History of the stocks used in crossing 345 



Methods 347 



Discussion 347 



Bibliography 355 



PART IV. Effects on fertility of crossing within and without an 



inconstant stock of drosophila 



Introduction ■ 356 



Fertility of the extracted truncates 357 



Productivity of the extracted truncates 360 



Fertility of the extracted truncated back-crossed to their grandparents, 



the original truncate stock and the Woods Hole stock 361 



Fertility of the long-winged brothers and sisters of the extracted truncates 367 

 Effect on fertility of crossing the truncates with their long-winged 



brothers and sisters and the efTect on fertility when both of these forms 



are crossed into the Woods Hole stock 368 



^ This part of the work was carried out at the Marine Biological Laboratory at 

 Woods Hole, Mass. The writer is indebted not only to the management of the 

 Station, but also to the Zoological Department of Columbia University for placing 

 at his disposal every opportunity for carrying forward the present study. I wish to 

 express my appreciation to Prof. T. H. Morgan for the unfailing interest he has 

 taken in these studies. 



343 



THE JOURNAL OF EXPERIMENTAI, ZOOLOGY, VOL. 17, NO. 3 



