No. 580] INFERTILITY OF DROSOPHILA 247 



becoming stuck to the glass before its behavior towards 

 males could be studied. 



There are two ways in which this mosaic can be ac- 



counted for. If an egg of the round-eyed, rudimentary 

 female was fertilized by a female producing spermato- 

 zoon of the bar-eyed, long-winged male the result should 



