IOWA ACADEMY OF SCIENCE 
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tatic to roan and since this latter is manifestly untrue it is best to con- 
sider them as separate f actors. 
Roan is epistatic to the entire series of factors as may be shown from 
the three following records. One a roan Belgian stallion owned at a 
small town in Iowa (the name and ? address are lost) sired 254 colts of 
which 230 were red roan and 24 blue roan, these colts coming from all 
colors of mares. The second a roan Belgian stallion which stood for two 
years in northwest Warren county, Iowa, sired 112 red roans, 7 blue 
roans and 6 chestnuts, from mares of various coats. The third, also a 
Belgian, owned in Marshall county, 111., sired about half roan colts and 
the other half grays, blacks, bays, browns, and sorrels. His owner states 
that his sire was blue roan, his dam was bay, his second dam was chest- 
nut and his dam’s sire brown. A roan Belgian owned in southeast Story 
county has sired 256 colts, all red roans, from all colors of mares. 
SPOTTING. 
Spotting varies in type but may receive at least two classifications. 
The white stockings on the legs and the blazed face typical of the Eng- 
lish breeds, Shire, Clydesdale, Hackney, Thoroughbred and allied breeds, 
seems to be inherited as a distinct kind of spotting although it fluctuates 
very markedly in amount of white. The “blaze” may become as small 
as the typical star in the forehead or may cover more than half the head. 
The stockings may extend well up to the elbow or stifle or may be 
restricted to the foot. 
Dr. Walther recognizes another type of spotting, S ch abrackenscheckung 
or saddle cloth marking and its recessive, absence of same. He finds it 
also inherited as a distinct unit although fluctuating in its limits. It is 
a spreading of white over the back, sides and croup, and down onto the 
legs. It is dominant and may appear wfith any color so far discussed. 
It is apparent what the horse breeder calls piebald or skewbald or what 
the average person calls a “calico” horse. 
Albinos are uncommon, but extreme spotting with blue eyes (glass 
eyes) are frequently seen. 
THE REDUCTION OP PIGMENT IN MANE AND TAIL. 
Yellow manes and tails in sorrels and cream colored extremities in 
duns are very common. They are apparently recessive since one chestnut 
mare Bessie at the Iowa State College has produced eight chestnut colts, 
six with manes the same color as the body, two with the yellow mane. 
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