Ko.562] 



COAT COLOR IN HORSES 



621 



bay, gray and roan. The percentages are from a total of 

 298 black X black matings : 91 per cent, black, 3 per cent, 

 chestnut, 4 per cent, brown, 2 per cent. bay. The brown 

 and bay from black matings are very small, not enough 

 to vitiate the conclusion that black is hypostatic to these 

 two colors as well as to gray and roan. Under the 

 present methods of registration there can be no sharp line 

 of demarcation between black and brown. I am confident 

 that as the records are now made up enough errors have 

 crept in, by registering browns black, to account for the 

 exceptions above mentioned. From true black horses 

 mated to true black only black and chestnut will be ob- 

 tained, in my opinion. The percentages of black colts 

 from the cross of black and brown and black and bay are 

 35 per cent, and 22 per cent., respectively; just about the 

 figures that the Mendelian law would justify. 



In regard to brown and bay no little difficulty is en- 

 countered. Wilson says: 



The relative positions of bay and brown remain to be settled; and 

 although there is evidence in favor of brown being dominant to bay, this 

 conclusion is not clearly established. It must be remembered these are 

 the colours breeders have the greatest difficulty in discriminating; and 

 errors effect sires and dams and foals. In regard to sires it has been 

 possible to correct the registered colors in several cases; and while 



dominant, it is still possible there may be other explanations, as, for 

 instance, that bay is a diluted brown. 



Wilson's conclusion is that brown is dominant to bay, 

 although he expresses a doubt as to the correctness of 

 his own conclusions. 



In his interpretation of the figures, Sturtevant goes the 

 line of least resistance. He says : 



I am unable to agree with Wilson that bay and brown can satis- 

 factorily be separated I base this upon my own observation, upon 

 the frequent changes from bay to brown and vice versa which he 

 (Wilson) mentions finding in the Clydesdale records, and the similar 

 changes which I have observed among Harness Horse records, and 

 upon the frequent recording of English Thoroughbreds as "bay or 

 brown." My conclusions, then, are that brown and bay are not distinct, 

 brown being" merely a dark bay. 



