PART V. THE MARKINGS OF THE HORSE.
Markings
Darwin wrote of the probable "descent of all existing races from a single dun-coloured, more or less striped primitive stock to which our horses occasionally revert."
The stories of the Great Ice Age and of Bering Land have shown us a variety of swiftly changing climates in which the original three-toed dun striped ancestors begat a special type of horse for each kind of habitat. The high lands and high latitudes, the low lands and low latitudes, the tall grasses, the short grasses, the open woodlands, the northern downs and valleys, bred each their special type of the wild horse.
EVIDENCE OF THE WIND. It is not so very long since the last clumps of timber vanished from the steppes. Still on the North American range one finds the trunks and roots of forest trees, which silicate swamps have changed into masses of jaspar onyx and chalcedony; and these have not had time to sink as stones do into the soil. In a seven hundred mile ride across the Canadian plains, I found a living clump of three pines distant a hundred-and-fifty miles from the edge of the shrunken forest. Such shelters have indeed so lately disappeared that the horse has not yet learned the trick of wind endurance. If his ears and nostrils were not so fearfully sensitive, he need only face up wind, and the hair of his body would be blown down flat to protect him. As it is, the extreme sensitiveness of his face compels him to stand or drift with buttocks turned to the gale, tail tucked, head down. It is only in that position that the hair is blown up from the skin and fails to give him protection. We may conclude then that he was inured to torrid summers and even to polar winters before he had to encounter strong gales away from shelter. Long after the three-toed ancestor had become a horse, the steppes had abundant tree clumps for wind breaks in heavy weather.
African bays
THE AFRICAN BAY. In every striped horse it seems a general rule that the body stripes are curved in such a way as to point to a spot on the ground midway between the four legs. The leg bands merely cut the upright lines of the limbs so that these disappear. Some natural process of colour photography has made the body stripes a bold copy of the upward and outward spread of the tussock grass. It was for concealment then among the rich forage of the tussocks that some of the parent species wore a gorgeous livery which passed on to the Zebra.
The Saharan range