The productions of Tibet consist of domestic animals, cattle, horses, pigs; some wild animals, such as the white-breasted argali, orongo-antelope, ata-dzeren, wolf, and steppe-fox; and few plants or forests, presenting a strong contrast with Nípal and Butan, where vegetable life flourishes more luxuriantly. Sheep and goats are reared in immense flocks, for beasts of burden over the passes, and for their flesh, hair, and coats. Chiefest among the animals of this mountain land is the yak.[137] The domesticated variety, or long-haired yak, is the inseparable companion and most trusty servant not only of the Tibetans, but of tribes in Cashmere, Ladak, Tangout, and Mongolia, even as far north as Urga. It is a cross-breed, or mule from the yak bull and native cow, which alone is hardy enough for these elevated regions.[138] These creatures are of the same size as our cattle, strong, sure-footed and possessed of extraordinary endurance; they retain, however, something of their wild nature, even after long domestication, and must be carefully treated, especially when being loaded and unloaded. They thrive best in hilly countries, well watered and covered with grass--the two last being indispensable. The hair is black or black and white, seldom entirely white. One sort is without horns, and when crossed with the cow bears sterile males, or females which are fertile for one generation. As to the wild yak of Tibet, a traveller says: “This handsome animal is of extraordinary size and beauty, measuring, when grown, eleven feet in length, exclusive of its bushy tail, which is three feet long; its height at the hump is six feet; girth around the body eleven feet, and its weight ten or eleven hundred weight. The head is adorned with ponderous horns, two feet nine inches long, and one foot four inches in circumference at the root. The body is covered with thick, black hair, which in the old males assumes a chestnut color on the back and upper parts of the sides, and a deep fringe of black hair hangs down from the flanks. The muzzle is partly gray, and the younger males have marks of the same color on the upper part of the body, whilst a narrow, silvery-gray stripe runs down the centre of the back. The hair of young yaks is much softer than that of older ones; they are also distinguishable by their smaller size, and by handsomer horns, with the points turned up. The females are much smaller than the males, and not nearly so striking in appearance; their horns are shorter and lighter, the hump smaller, and the tail and flanks not nearly as hairy.”[139] This animal is useful for its milk, flesh, and wool, as well as for agricultural purposes and travel. ~ANIMALS OF TIBET.~