Group I. 



89 



Exp. 51. — Oblique singed. 

 Mating: oblique X singed. 



Per cent cross-overs: o-si, 4.2. 



Exp. 52. — Sepia oblique singed short. 

 Mating: sepia oblique short X singed. 



Per cent cross-overs: se-o, 19.1; o-si, 5.4; si-s, 31.8; counting all flies, se-o. 19.7; o-si. 5.6; 

 si-s, 28.1, counting only not-o flies. 

 "After apportioning se, o, and o. 



Exp. 53. — Sepia oblique singed. 

 Mating: sepia oblique X singed. 



Per cent cross-overs: ae-o, 17.3; o-si, 6.7; counting all flies, se-o, 19.4; o-si, 7.4. counting only 

 not-o flies. 



o After apportioning ae o, and o. 



