NEW DATA. 



63 



SHIFTED. 

 Shifted appeared (January 191 3) in a stock culture of vermilion dot. 

 The chief characteristic of this mutant is that the third longitudinal 

 vein (see text-fig. f) does not reach the margin as it does in the nor- 

 mal fly. The vein is displaced toward the fourth throughout its length, 

 and only very rarely does it extend far enough to join the marginal 

 vein. The cross-vein between the third and the fourth veins is often 

 absent because of the shifting. The flies themselves are smaller than 

 normal. The wings are held out from the body 

 at a wide angle. The two posterior bristles of 

 the scutellum are much reduced in size and 

 stick straight up — a useful landmark by which 

 just-hatched shifted flies may be recognized, 

 even though the wings are not expanded. 



LINKAGE OF SHIFTED AND VERMILION. 



Since shifted arose in vermilion, the double 

 recessive shifted vermilion was available for 

 the following linkage experiment: shifted ver- 

 milion males by wild females gave wild-type 

 males and females which inbred gave the data 

 shown in table 46. 



Disregarding the eye-color, the following 

 is a summary of the preceding results: wild- 

 type?, 1,001; wild-typed', 437; shifted c^, 

 328. The result shows that shifted is a 

 sex-linked recessive. The data of table 46 

 show that the locus of shifted lies about 15 

 units on one side or the other of vermilion, fig. f.— shifted venation. The 

 which from the calculated position of ver- third longitudinal vein is shifted 



•1- 11- • • r 1 •/• toward the fourth and fails to 



milion at 33 would give a position for shifted reach the margin. Cross-vein 



at either 18 or 48 from yellow. between third and fourth longi- 



-^ ' tudinal veins is lacking. 



Table 46. — Pi shifted vermilion cf cT X zvild 9 9 



X Fi zvild-type cf cf . 



Fi zvild-type 9 



