Feb. i? t 1923 
Inheritance in Swine 
563 
tainly so rare that it plays little part in the ordinary colors. Self-white 
breeds are fairly numerous, there being at least five known in America 
and one, the Edelschwein, in Germany. 
The Edelschwein self white has been found dominant to the striping 
and agouti pattern of the wild hog (4), and the Yorkshire and Chester 
White self whites have been reported dominant in the F x generations 
over one kind of Tam worth ( 12 ) and Duroc-Jersey self red, and over 
Hampshire, Berkshire, and Poland-China (17) black and has produced a 
red-and-white roan in the F 4 of a cross with some Tamworths and Duroc- 
Jerseys whose self red color seems to be genetically different from the 
more common red color of their breeds (19, 20). The black of Berk¬ 
shire and Poland-China segregates in a 1 to 3 ratio in the F 2 generation, 
but the black pigs obtained as recessive carry more and larger white 
spots than the pure-bred Poland-China or Berkshire. Evidently there 
are some minor factors which modify the extent of this kind of black and 
which are inherited independently of the main factor for black or its 
allelomorph (17). 
Another form of white which appears to be quite distinct, genetically, 
from self white and from the white spotting displayed by the Berkshire 
and Poland-China is the white belt, “sheet,” or “list,” as it is sometimes 
known to breeders, which is characteristic of the American Hampshire 
hog and, in a more extended form, of the German Hanoverian swine. 
This white pattern is dominant, although not always completely so, 
when crossed with all other colors upon which it has been tried, including 
even the striping and agouti pattern of the wild hog (4). The swine in 
this case were Hanoverian sows bred to a wild boar. The white belt of 
the Hanoverian is so extensive that usually the only parts which remain 
colored are the head and a part of the rump, while in the American 
Hampshire the white belt includes only the front legs and feet and a belt 
usually from 4 to 12 inches wide around the body. The two patterns 
are probably of the same kind genetically, except that the two breeds do 
not possess the same modifying factors for the width of the belt. Even 
in pure Hampshires, the inheritance of the belt can not be determined 
by less than two factors (19, 20). Simpson has succeeded in producing 
belted red hogs by crossing the Hampshire and Tamworth and extract¬ 
ing reds from later generations (12). 
A second kind of white pattern is that possessed by the Poland-China 
and Berkshire breeds. These are black except for white feet, a white 
splash in the face, and white on the end of the tail. These six white 
points constitute the standard color for both breeds, but quite frequently 
there are one or more white splashes elsewhere on the body, and occa¬ 
sionally an animal appears which is not pure white but a sandy color in 
one or more of these “white points.” The complete pattern is mani¬ 
festly not dependent on a few factors, since it breaks up so readily into 
black spotting on a white, sandy, or red ground color in crosses and is 
so difficult to obtain in typical form in the F 2 generation. 
A possible third kind of white pattern is found in the breed known as 
the Spotted Poland-China. White and black, in approximately equal 
amounts irregularly scattered over the body, constitutes the standard 
color of this breed. Wright suggests (24) that it is doubtful whether this 
is really a different kind of white pattern from that of the Berkshire and 
Poland-China, since both of these breeds at a not very distant time were 
sandy white or reddish brown with large black spots. Furthermore 
when they are crossed their present color readily breaks up into a form 
