644] MUTANT CHARACTERS IN DROSOPHILA 217 



by. It recalls singedo of melanogaster although singedj 

 is slightly more extreme. 



Origin.— Seven males were found in a stock bottle. 

 Since no forked females were obtained, it is possible that 

 this was the original appearance of the mutant and that 

 all of the forked flies were from one mother, heterozygous 

 for forked. 



Forked-2 ih) 



Description— This character is nuicli more extreme 

 than its allelomorph, forked, or the similar mutant, stub- 

 by. The bristles are twisted and thickened with their 

 ends often split (Fig. 4). The twisting also affects prac- 

 tically all the hairs on the fly, including those on the inner 

 margin of the wing. The hairs on the antennae are forked. 

 Forked-2 resembles the melanogaster singed. The fe- 

 males are sterile. 



On>m.— Several forked-2 males and one female ap- 

 peared in a stock bottle of small-bristle flies. 



