CHAPTER XIV 



UNIT-CHARACTERS IN SWINE, SHEEP, DOGS, AND CATS 



Swine. In the wild boar of Europe, from whicli in part 

 domestic swine are descended, the coat is slaty black, the 

 individual bristles bearing a band of pale yellow like the 

 agouti marking of rodents. The young of the wild boar are 

 also marked with longitudinal body stripes, a character per- 

 haps correlated with the agouti-like banding of the bristles. 

 This banded character of both young and adult has appar- 

 ently been lost in all domestic breeds, which are either self 

 black, red, or white, or else black or red spotted with white, 

 yet it occasionally reappears in crosses, showing a probable 

 dependence upon complementary factors still found sepa- 

 rately in certain breeds (Severson) . In the white variety the 

 entire coat is colorless but the eye is colored. This is a domi- 

 nant variation. White spotting is possibly a distinct varia- 

 tion from the foregoing, and uncertain as to dominance. But 

 it may be that the two differ only in degree and are really 

 allelomorphs. 



TABLE 15 



Unit-Characters of Swine 

 Dominant Recessive 



1. Wild color. Not wild color (black or red). 



2. Black. Red. 



3. Self white. Colored. 



4. Mule-footed (syndactyl). Normal foot. 



Dominance Uncertain or Wanting 



5. Uniformly colored. Spotted with white. 



Two forms of white spotting (which occur naturally and are 

 comparable with the two types of white spotting amouii 

 horses) are sought after by breeders and have become breed 

 characters, viz., (1) a condition in which a broad wliite belt 

 encircles the body (as in Hampshire hogs) and (2) a condition 

 in which white appears at the extremities, on the feet and 



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