296 



THE SECOND-CHROMOSOME GROUP 



CHROMOSOME CARRYING DACHSOID. 



The four cultures above noted (table 139) all gave both male and 

 female dachsoids, thus showing at once that the gene is not in the X 

 chromosome. The mothers of all four were heterozygous for sepia, 

 spineless, kidney, sooty, and rough — characters that cover practically 

 the whole length of the third chromosome, and the same was true of 

 several later cultures that also gave dachsoid. The dachsbid char- 

 acter was distributed quite at random with respect to these third- 

 chromosome characters, showing that the gene is not in the third 

 chromosome. 



Text-figure 86. — Dachsoid venation. 860 shows the small size of the flj', with the wing pos- 

 ture; 866 shows a typical wing. 



An F3 from a cross between speck and a fly that proved to be heter- 

 ozygous for dachsoid produced 15 dachsoid, but unfortunately the 

 speck character was not examined (2859, A. H. S.). 



An F3 pair (2926) gave a total of 40 flies, of which 4 were dachsoid, 

 26 speck, 10 wild-type, and none dachsoid speck. The count was 

 aberrant in that there were far too few wild-type offspring; but the 



