Cases of mimic mutations and secondary mutations in the X-chromosoiut- 1^:1 



19 



Table 7. Pi, Forked- male ex sinjied stock X Bar oo; B. C, 

 Fl Bar $ X forked- ocT (1994) and X Bar (1998). 



The new chanifter was thus found to be due to a sex-linked recessive 

 gene which is closely linked to Bar. It was also found that the 

 character is sex-limited to some extent, being generally more pronounced 

 in females than in males. In the males the cha- 

 racter shows a fairly wide range of variability: 

 In some cases it is well pronounced and affects 

 most of the bristles of the thorax; in other cases 

 the alteration is restricted to a few or even a 

 single bristle which is bent at sharp angle oi- 

 bifurcated. It is therefore possible that the three 

 males classified as wild-type crossovers in table 5 

 were genetically forked-. In distinction from the 

 ordinary forked character the ])ristles are long and 

 fairly graduaUy tapered, though often somewhat 

 thicker than those of wild-t^-pe flies. The typically 

 crinkled aspect of forked bristles is not found, and 

 the bristles of the head are rarely affected (Fig. 4). 



That the new gene is allelomorphic to forked was finally proven 

 by crossing forked ^ males to forked females from stock. All the daugh- 

 ters were forked. The new mutation being the first recorded allelomorph 

 of forked was called forked^. 



In somatic character the f — f^ compound can hardly be separated 

 from ordinary forked. The allelomorph which in homozygous condition 

 causes the most extreme somatic alteration has also the strongest effect 

 in determining the somatic appearance of the compound. This is the 

 same result as the one obtained in the f — f^ compound. 



GyDandromorph 1819. 



A gynandromorph arose in Culture 1819, which was a back-cross 

 of an Fl Notch 8 female heterozygous for ruby- and singed to ruby- 

 singed males (Nov. 15, 1919). 



Fig. 4. Forked* male. 



