14 Wentworth. 



seems possible that there also exists a chestnut roan, in fact they 

 are apparently quite common, for roans with red pigmented manes 

 and tails instead of black are seen frequently. Such a roan would 

 probably be the type produced by the mating of blue roan to blue 

 roan shown in the table. If the black factor were heterozygous in 

 both sexes, the chestnut roan would result. 



Roan differs from gray in lacking the dappling common to gray 

 and in possessing quantitatively a much larger number of pigmented 

 hairs. It has seemed to the writer that gray may be a combination 

 of the roan, dappling and dilution factors coupled together in some 

 way, but since from the present evidence that would necessitate 

 considering gray epistatic to roan and since this latter is manifestly 

 untrue it is best to consider them as separate factors. 



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 chestnut and his dam's sire brown (i). 



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 

 English 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, Schabracken- 

 scheckung or saddle cloth marking and its recessive, absence of same. 



{'■) Since the above records were prepared an instance has been discovered of 

 a roan Belgian stallion in southeast Story county, Iowa, that has sired 256 red roan 

 colts to the exclusion of other colors. 



