As he went on up, the appearance was like a stage effect, as though he were sustained by wires. At the end of the crack he reared, hooked his fore feet over a rough point, and drew himself up like an athlete, with utter indifference to the two hundred feet of drop beneath him. From this point he tacked back and forth until he had ascended to the bottom of a vertical gully, which he easily mastered with a series of zigzag jumps. In some of these he leaped several feet almost horizontally to gain a few inches vertically. Occasionally he leaped up and struck with his feet in a place where he could not stand, but from which he leaped to a place more roomy. His feet slipped as he landed from one high jump; instantly he pushed himself off backward and came down feet foremost on the narrow place from which he had just leaped. He tried again and succeeded. The edges of sheep's hoofs are hard, while the back part of the bottom is a rubbery, gristly pad, which holds well on smooth, steep surfaces. Coöperating with these excellent feet are strong muscles, good eyes, and keen wits. Wild sheep are much larger than tame ones. They are alert, resourceful, and full of energy. Among the Colorado bighorns the rams are from thirty-eight to forty-two inches high, and weigh from two hundred to three hundred and fifty pounds. The ewes are a third smaller. The common color is grayish brown, with under parts and inside of the legs white. In the north there is one pure-white species, while on neighboring ranges there is a black species. Though wild sheep usually fallow a leader, each one is capable of independent action. Tame sheep are stupid and silly; wild sheep are wide-awake and courageous. Tame sheep are dirty and smelly, while wild sheep are as well-groomed and clean as the cliffs among which they live. In discussing wild life many people fail to discriminate between the wild sheep and the wild goats. The goat has back-curving spike horns and a beard that makes the face every inch a goat's. Though of unshapely body and awkward gait, his ungainliness intensified by his long hair, the goat is a most skillful climber. The sheep excel him for speed, grace, and, perhaps, alertness. It is believed that the three or four species of sheep found in the wilds of America had their origin in Asia. In appearance and habits they bear a striking resemblance to the sheep which now inhabit the Asiatic mountains. Wild sheep are found in Alaska, western Canada, and the United States west of the Plains, and extend a short distance down into Mexico. Most flocks in the Sierra and the Rocky Mountains live above the timber-line and at an altitude of twelve thousand feet. Winter quarters in these high stamping-grounds appear to be chosen in localities where the high winds prevent a deep accumulation of snow. This snow-removal decreases the danger of becoming snowbound and usually enables the sheep to obtain food.