No. 644] MUTANT CHARACTERS IN DROSOPHILA 215 



Orange (o) 



Description.— The eyes are orange colored. In newly 

 hatched flies, the color is a pale lemon, which deepens 

 into orange as the fly matures and may become very 

 dark in old age. The color resembles garnet or coral of 

 D. melanogaster. 



Origin.— ^One male appeared among the offspring of 

 a mating of three normal females by an unrelated male. 

 The other offspring were all normal, but their number 

 was not recorded. Presumably, the mutation occurred in 

 one of the Pi females and affected only one or a few genn 

 cells, although it is possible that this female was hetero- 

 zygous and produced a very small number of the flies in 

 the culture. 



Small-bristle (sb) 

 Description. — All the bristles are more slender and 

 somewhat shorter than in normal flies. The character 

 is extreme when orange eye color is also present. 



