D. E. LANCEFIELD. 



of the bar gene. One of these females, which was heterozygous 

 for eosin and miniature, was crossed to an eosin miniature 

 brother. The offspring showed no bar, but the eosin flies were 

 very variable, some appearing darker than usual and some lighter 

 like eosin. This was probably totally unrelated to the reversion 

 of the bar factor, for the next generation, produced from eosin 

 flies of the above mating, showed unexpected results. A great 

 variety of eye colors were present. Two of these were the two 

 new mutants found March 18, 1918 and the other colors were 

 different combinations with eosin. The scarlet individuals were 

 thought to be vermilion until the gene was found to be not 

 sex-linked. The pinkoid flies had an eye-color very closely 

 resembling that of the mutant race known as pink, but had the 

 further interesting characteristic that the wings were also very 

 greatly affected, resembling typically the wings of the "inflated" 

 stock, which is sex-linked. When the eyes were pinkoid the 

 wings were always abnormal, being either inflated as if by a 

 bubble of air or else being shortened and wrinkled. That both 

 the eye-color and the wing character are the result of the same 

 gene is probable because they appeared at the same time in the 

 same individuals and all efforts to obtain the eye-color separate 

 by outcrossing and back crossing have failed. 



Owing to the circumstances surrounding the appearance of 

 these two mutants, nothing can be said concerning the stock 

 from which they arose. When first observed, eosin was also 

 present and altogether a most remarkable array of colors was 

 produced. The homozygous form of either new mutant with 

 eosin is white in appearance. The colors ranged from this 

 multiple white up through cream, lemon, eosin, orange, pinkoid 

 to normal red ; according to the combination existing in any one 

 individual. 



LOCATION OF NEW GENES. 



Pinkoid and scarlet were not sex-linked and were found to be 

 freely segregating from each other. Such segregations indicated 

 that they were in separate autosomes. Accordingly they were 

 each crossed to the double dominant form star dichsete, the 

 genes of which are in the second and third chromosomes respec- 

 tively. A star dichaete male resulting from these crosses was 



