Page:The Evolution of British Cattle.djvu/110

 the others are masqueraders—hybrids, like the roans, although they pretend to be otherwise.

The explanation is that, while one half of the colour determinant of these crosses is for blackness—derived from the black parent—and the other half for redness—derived from the red parent—the relationship between blackness and redness is such that blackness holds the mastery -and obscures or hides redness. Redness is all the time latent, however. In Mendelian phraseology, blackness is dominant to redness, and redness is recessive to blackness.

These phenomena may be made clear diagrammatically. We shall use letters instead of circles, and, for convenience, we shall use capitals to denote the dominant characters and small letters to denote the recessive.

Black cattle mated with red produce masquerading black hybrids, thus—

gives only.

When masquerading black hybrids are bred together, their progeny receive their colour determinant, one half from each parent, and the chances are: one that both halves will be black, two that one half will be black and the other red, and one that both will be red. It may be a union of these, these, ; or