562 
Journal of Agricultural Research 
Vol. XXIII, Na 7 
may be interpreted to mean that such correlation as exists is develop¬ 
mental or anatomical rather than genetic (linkage). 
The data from this cross seems to show that the Berkshire type of 
face is largely but not completely dominant over the Duroc-Jersey 
type. Probably several factors differing in importance and in degree 
of dominance are responsible for the anatomical differences that de¬ 
termine the face shape. Certain of these factors affect certain parts of 
the face much more than they do other parts. If reliable means of 
measurement had been developed for the different aspects of face shape, 
it might have been possible to distinguish enough separate phenotypes 
to postulate a factorial analysis. In the absence of such an analysis it 
would be impossible even to estimate the number of factors involved, 
beyond calling attention to the fact that the true number can not be so 
large as to make analysis impossible, else the parental types would not 
have been recovered among such limited numbers. 
RfiSUMlS OF WORK ON SWINE COLOR (24) 
In spite of the rapidity of their multiplication and the diversity of 
characters which they offer, very little genetic research has been conducted 
with swine and that which is known or seems very probable in regard 
to the inheritance of their colors can be stated in a very few paragraphs 
(1, p. 476). 
The agouti color common to so many mammals is found among 
swine in the European wild hogs. This color, which is fundamentally 
a pattern of bands of different shades of sandy, red, black, or brown 
pigment on each individual hair is a darker, more slaty shade in the 
adult wild hog than is usual among other mammals. It is also charac¬ 
terized by being much lighter along the underline than on the sides 
and back. Moreover, in the wild hog the young are bom with longi¬ 
tudinal stripes instead of being self-colored. 
The European wild hog (PI. 2A) has been crossed with the domestic 
breeds of hogs by Simpson in Illinois (ir, 12, rj, 14, 15, 16) and by 
Herrmann and by Henseler among others in Germany as stated by 
Frohlich (4, p. 219, 220-221) but as yet there has been no very large 
F 2 generation produced. In the F t generation the striping pattern of 
the young and the agouti pattern of the adult have been reported dom¬ 
inant over the self red of Tamworths and the black with six white points 
of the Berkshire and incompletely recessive to two patterns—that of a 
white belt on a colored background and that of self white (4, 14, 15, 18 ). 
Simpson’s data from a cross with Tamworths indicate that this wild 
color differs from red by a single factor. 
Each individual hair of domestic swine is either white, black, or some 
shade of red; but within these limitations there is a wide range of colors, 
not only in the scrubs and grades which constitute the average market 
run of hogs but also between the various pure breeds. Thus there are 
self red, self black, and self white breeds which breed true to pattern, 
besides a recently established breed which is a black and white roan or 
“blue.” Also, although there are no pure breeds of these colors, ordi¬ 
nary unpedigreed hogs are common which are red-and-black, red-and- 
white, red-black-and-white, red-and-black roan in spots, or red-and- 
white roan in spots. Red may be replaced by various lighter tints, 
ordinarily known as sandy, in any of these combinations. There appears 
to be no record of true albinism in the pig. If it does occur it is cer- 
