CHAPTER XIII 



UNIT-CHARACTERS IN CATTLE AND HORSES 



Unit-character changes have produced new varieties 

 among our more important domesticated mammals as well 

 as among our pet rodents. 



Cattle. Among cattle four or five Mendelizing color varia- 

 tions occur similar to those of rodents and in addition two 

 variations of a morphological character have been reported, 

 one of which has considerable economic importance. Wild 

 cattle existed within historic times in central Europe, the 

 hunting of the last-existing herds being held as a royal pre- 

 rogative by the kings of Poland. These cattle represented 

 probably the chief source from which domesticated cattle 

 were derived. They were of large size but of what color we 

 do not certainly know. It seems probable, however, that 

 their coat, like that of most wild ruminants, contained a 

 mixture of yellow and black pigments somewhat like the 

 coat of Jersey cattle at the present time. In most existing 

 domestic breeds either the black or the yellow pigments have 

 become predominant or white has taken their place in whole 

 or in part. Such is the general tendency of man's agency in 

 modifying the color characters of his domesticated animals. 

 Nature's colors are usually adapted to concealment or pro- 

 tection. Mixtures of pigments are common and minute color 

 patterns abound. Man seeks to make his domestic animals 

 as different as possible from the wild. He either gives pre- 

 ference to pure colors, black, white, or yellow, or seeks to 

 outdo nature in the production of color patterns in great 

 blotches of two or three colors. The materials for his opera- 

 tions consist of sports to solid black, yellow, or white, 

 together with white spotting and yellow spotting. All of 

 these have occurred among cattle and have been used to the 

 fullest extent. 



130 



