Reversal of Dominance and Production of a Secondary Sexual Character in the Mediterranean Flour-Moth

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Abstract
Black, b (wings and body), is a simple recessive to normal gray, B, Sooty, S (darkening base and margin but lightening mid-area of wings), is an irregular dominant, but in black moths S is recessive. Of the 18 possible crosses involving sooty and producing black, 11 show 8 new ratios. If classes be given in order Sooty, Type, Black Sooty, and Black, there are from BbSs X BbSs (theoretical 9:3:1:3), 1539:552: 144:437; from BbSs X bbsS (theoretical 3:1:1:3),187:68:55:177; from BbSS X BbSs (theoretical 6:0: 1:1), none bred; from BbSSXbbsS or BbSsXbbSS (theoretical 2:0:1:1), 635:0:233:298; from BbSSX Bbss (theoretical 3:0:0:1), none bred; from BbSSX bbss or BbssXbbSS (theoretical 1:0:0:1), 157:0:0: 152;from BbSsXBbss (theoretical 3:3:0:2), 26:33:0: 30; from BbSsXbbss or BbssXbbsS (theoretical 1:1: 0:2), 182:165:0:358. Departures from expectation on the basis of reversal of dominance of sooty by black may be seen in certain crosses in which minor darkening factors enter. Thus a critical point may be reached at which a secondary sexual difference, not seen in gray or in ordinary black moths, becomes apparent. Where black sooty and black should stand in ratio 1:3 we have black sooty [male] 157, [female] 101, intermediate [male] 21, 9 18, black [male] 380, [female] 416. Where corresponding ratio should be 1:1 we have black sooty [male] 174, [female] 122, black [male] 169, [female] 223. Since black sooty is distinguished from black by lightening of the mid-area, these results indicate that cf have a tendency to be lighter than [female].

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