Wilson — The Inheritance of the Dun Coat-Colour in Horses. 187 



a teadeney to return to them, and sometimes it would seem capriciously to 

 resume the bay, dun, grey, or black. "^ Smith said also that, while the five 

 original stirpes were all represented among tame horses, " the dun is typical 

 of the generality of the real wild horses, still extant in Asia, and the semi- 

 domesticated, both tliere and in Eastern Europe. Besides the general form, 

 tlie smaller square head, great length of mane, tendency to black limbs, it is 

 known by the black streak along the spine, sometimes, though very rarely, 

 crossed by a second of a fainter colour on. the shoulders, and often marked by 

 black streaks on the hocks and upper arms."^ 



It was left to Darwin to set aside all other stirpes, and, after first suggesting 

 the descent of all kinds of horses from a striped race, eventually to suggest 

 them as tracing back to a race that was both striped and dun. In " The 

 Origin of Species" (1859) he rejected Hamilton Smith's theory "that the 

 several breeds of the horse are descended from several aboriginal species,'' 

 and went on to say that, although he had " collected cases of leg and 

 shoulder stripes in horses of very different breeds in various countries, . . ." 

 yet "in all parts of the world tliese stripes occur far oftenest in duns and 

 mouse-duns." He found them also in mules and in other equine crosses, and 

 mentioned the striped foals of Lord Morton's chestnut mare. Then, seeing 

 the appearance of such stripes to be parallel to the occasional appearance of 

 "slaty blue birds with two black bars on the wings," and so on, among 

 pigeons, he summed up thus : — " For myself, I venture confidently to look 

 back thousands on thousands of generations, and I see an animal striped 

 like a zebra, but perhaps otherwise very differently constructed, the common 

 parent of our domestic liorse (whether or not it be descended from one or 

 more wild stocks), of the ass, the hemionus, quagga, and zebra."' But, in 

 " The Variations of Animals and Plants under Domestication " (1868), the 

 dun colour is added to the stripes as a characteristic of the ancestral horse, 

 although the new evidence in support of the addition is not very great. The 

 second chapter of this book is devoted to horses, and consists mainly in an 

 extension of the argument contained in " The Origin of Species." It is stated 

 that duns are barred and striped more frequently' than other species — but not 

 that duns only and that all duns are barred — that, in places, duns are not 

 considered pure-bred unless they are striped ; and, from the fact tliat wild 

 and semi-wild horses in Europe and Asia and feral horses in America* are, 

 many of them, dun, it is inferred that dun is obviously the colour of wild 



1 " Natural Histoiy of Horses," p. 199. - Ibid., p. 274. 



3 " Origin of Species," 1897 ed., pp. 117 to 122. 



^ Eidgeway has shown that Cortes took dun horses witli him to Mexico : " Origin and Influence 

 of the Thoroughbred Horse," p. 267. 



