98 EVOLUTION OF BRITISH CATTLE 



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 dia- 

 grammatically. 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 masque- 

 rading black hybrids, thus — 



g X ^ gives only ^. 



When masquerading black hybrids are bred 

 together, their progeny receive their colour de- 

 terminant, 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 



, , B->B M B^ B 



a union of these, ^ ^ ' ^^ these, ^X^ ^ ; or 



