8o 



SEX-LINKED INHERITANCE IN DROSOPHILA. 



FURROWED. 



In studying the effect of hybridization upon the production of 

 mutations in Drosophila, F. N. Duncan found a sex-Hnked mutation 

 which he called "furrowed eye" (Duncan 1915). The furrowed flies 

 are characterized by a foreshortening of the head, which causes the 

 surface of the eye to be thrown into irregular folds with furrows 

 between. The spines of the scutellum are stumpy, a character which 

 is of importance in classification, since quite often flies occur which 

 have no noticeable disturbance of the eyes. 



The locus of furrowed was determined to be at 38.0 on the basis of 

 the data given in table 61. 



Table 61. — Data on the linkage of furrowed, from Duncan, iQij. 



ADDITIONAL DATA FOR YELLOW. WHITE. VERMILION. AND 



MINIATURE. 



Considerable new work has been done by various students upon the 

 linkage of the older mutant characters, namely, yellow, white, vermilion, 

 and miniature. We have summarized these new data, and they give 

 values very close to those already published. We have included in the 

 white miniature data those published byP.W. Whiting (Whiting 1913). 



