Two plumage-color variations are found in the Fayoumi: dark and light. The dark phase is an autosomal barring or penciling and the light phase is a columbian-type pattern. Evidently these variations are determined by segregation at the autosomal E locus. From the genetic analysis of Brumbaugh and Hollander (1965), we assume that the gene for dark plumage corresponds to ep and is dominant to ey for light plumage. Almost invariably, shank color of birds with dark plumage is slate or green (melanin) and, of birds with light plumage, is yellow or white (nonmelanin). Melanin is thought to be controlled by a pair of sex-linked genes, Id for nonmelanin and id for melanin. In the Fayoumi, however, Mukherjee et al. (1969) proposed, in effect, that ep and id interact to produce shank melanin. They concluded that all Fayoumis carry id but that its expression is inhibited by the genotype for light…