The problem in nature was intricate as a jigsaw puzzle, before man's interference broke that puzzle into little pieces. Our ancestors were not such fools as to import Duns from Asia for purpose of breeding, but in their wars and migrations drifted Asiatic Duns and South Russian white horses across the face of Europe. No wars of invasion brought Bay horses out of Africa; but as each tribe needed a better strain of horseflesh, the Bays were carried in the courses of trade to Europe. THE HUMAN INFLUENCE IN CROSSING HORSE STRAINS. [Sidenote: Scale of colour values] THE CHESTNUT. This colour is possibly bright Bay from African blood crossed with a slight proportion of golden Dun. Both in the humans and the horses, chestnut hair goes with a certain temper described as sanguine, generous or fiery if we happen to be in a good temper, or untrustworthy and vicious if we dislike the person. Setting aside the cold sorrel, or light chestnut, which in my own mind is associated with commonplace horses and with one or two very bad women, the real chestnut, with its red-gold glory, makes most of us catch our breath with its beauty. In human {47} hair it so appeals to artists as to be generally reserved for the most sacred portraiture. In horses, it so appeals to horsemen as to rank next bright Bay in the scale of values. THE BROWN HORSE. This is a colder, washed-out tone of Bay. THE BLACK HORSE. Among feral and range horses, those of the very darkest bay and brown become brown-black under the summer sunlight. True black is unknown among outdoor horses, and can only be due to special selective breeding. THE GREY HORSE. All greys are obviously crossed between white and the various whole colours. The primary horse colours are Dun and Bay. The secondary colours are white, black, grey, chestnut, and brown, whole colours shared by human and horse folk. The tertiary colours are crosses of white with Bay, Dun, black, chestnut, brown, which produce the various roans. Beyond that the human hair withdraws from competition. The quarternary colours are crosses of white with whole roans, producing strawberry and cream roans, and roan-balds; while a peculiar mixture of white with black, bay or chestnut, gives us the piebalds and skewbalds. {48} The white horse has been saved from the wolves by man, but the secondary, tertiary and quarternary colours are also very largely the result of man's work in crossing the primitive strains of Europe with the imported African Bay within the last couple of thousand years. MIGRATION. The Romans imported millions of negro slaves who have not left a trace of their blood in Europe. Wave after wave of Blonde Migration from the Baltic has conquered the Mediterranean states, but left no fair descendants. The negroes become extinct in Europe. The blondes become extinct on the Mediterranean. [Sidenote: Correcting by sunlight]