UNIT-CHARACTERS OF CATTLE 131 



In English parks there have existed, since Roman days and 

 perhaps longer, herds of all-white cattle kept in a half wild 

 state. Some have supposed that these white cattle represent 

 the unchanged original stock of European wild cattle, but it 

 seems much more probable that they represent a striking 

 sport from the original stock, which was isolated and allowed 

 to increase in the hunting preserves of princes, a semi-sacred 

 character perhaps attaching to it. These cattle differ from 

 albinos among rodents in that they have pigmented eyes. 



TABLE 13 



Some Unit-Characters of Cattle 



Dominant Recessive 



Black. Yellow. 



Polled. Horned. 



Dexter form (short legs). Kerry form (legs normal). 



Dominance Uncertain or variable 



White. Colored. 



Uniformly colored. Spotted with white. 



Uniformly black. Black spotted with yellow. 



They also have some sooty black or brownish pigment in the 

 skin and hair of the extremities (feet, nose, ears, and tail). 

 Ordinarily they breed true, but occasionally an all black calf 

 is produced, but whether as a recessive in the Mendelian 

 sense or as a reversion, through recombination of comple- 

 mentary color factors, is unknown. (See Figs. 58 and 59.) 

 In any case it seems highly probable that the white race 

 resulted from an ancient sport derived directly from wild 

 cattle. In the breed of " short-horn " cattle, which origi- 

 nated in England, white individuals frequently occur and 

 they breed true when mated with each other. In matings 

 with red individuals, a sort which also breeds true, roan 

 heterozygotes are produced (as noted on page 110). The 

 white of this breed was probably derived from the same 

 original source as the white cattle of the English parks, but 

 the black character which seems to inhere in the cattle of the 

 parks has been eliminated from the short-horn breed, which 

 produces only reds, whites, and their heterozygotes, with or 

 without admixture of white spotting. (See Figs. 62-64.) 



