Abstract
1. The recessive mutant gene, ebony (body color), is sex-linked like fused in H. juglandis, worked on by Whiting and others, with the crossing-over value between ebony and the sex-determining factor ranging from 13 to 33 percent.
2. The sex-linkage of ebony entirely disappears in out-crosses, but distinctly reappears by inbreeding even directly after out-crossing. This favors the multiple-allele theory suggested by Whiting more than Snell's multiple-factor theory of sex-determination in this material.
3. These theories, are discussed, and a new 'compound sex-factor' theory is proposed.
