Coat Color Inheritance in Horses and in Other Mammals.

HE colors of horses have long been a subject of interest to owners and T breeders of horses as well as to scientists and much information about them is found in the stud-book records of particular breeds. Attempts to use this information in framing explanations of the observed results of matings within or between different color varieties have been made repeatedly since the rise of genetics at the beginning of this century. Such explanations assume the existence in the primitive undomesticated horse of certain genes for color production which have persisted unchanged in certain domesticated color varieties and undergone mutation in others to produce the genetic combinations recognizable in present-day horses. Most of the genetic explanations of horse colors have been based on a study solely of horses, ignoring the much larger and more exact knowledge of color inheritance which has been derived from experimental studies made on other mammals, rodents in particular. A comparative study utilizing this experimental evidence in discussing the genetics of color in horses was made by WRIGHT (1917) and more recently by ODRIOZOLA (1951). Believing this to be a correct method of procedure, I shall attempt in what follows to present a genetic frame-work for explaining horse colors in harmony with that derived from the experimental study of other mammals.