The sheep is the only animal that has circling horns. In rams these rise from the top of the head and grow upward, outward, and backward, then curve downward and forward. Commonly the circle is complete in four or five years. This circular tendency varies with locality. In mature rams the horns are from twenty to forty inches long, measured round the curve, and have a basic circumference of twelve to eighteen inches. The largest horn I ever measured was at the base nineteen and a half inches in circumference. This was of the Colorado bighorn species, and at the time of measurement the owner had been dead about two months. The horns of the ewes are small, and extend upward, pointing slightly outward and backward. The wildest leap I ever saw a sheep take was made in the Rocky Mountains a few miles northwest of Long's Peak. In climbing down a precipice I rounded a point near the bottom and came upon a ram at the end of the ledge I was following. Evidently he had been lying down, looking upon the scenes below. The ledge was narrow and it ended just behind the ram, who faced me only five or six feet away. He stamped angrily, struck an attitude of fight, and shook his head as if to say, "I've half a mind to butt you overboard!" He could have butted an ox overboard. My plan was to fling myself beneath a slight overhang of wall on the narrow ledge between us if he made a move. While retreating backward along almost nothing of a ledge and considering the wisdom of keeping my eyes on the ram, he moved, and I flung myself beneath the few inches of projecting wall. The ram simply made a wild leap off the ledge. This looked like a leap to death. He plunged down at an angle to the wall, head forward and a trifle lower than the rump, with feet drawn upward and thrust forward. I looked over the edge, hoping he was making a record jump. The first place he struck was more than twenty feet below me. When the fore feet struck, his shoulder blades jammed upward as though they would burst through the skin. A fraction of a second later his hind feet also struck and his back sagged violently; his belly must have scraped the slope. He bounded upward and outward like a heavy chunk of rubber. This contact had checked his deadly drop and his second striking-place was on a steeply inclined buttress; apparently in his momentary contact with this he altered his course with a kicking action of the feet. There was lightning-like foot action, and from this striking-place he veered off and came down violently, feet first, upon a shelf of granite. With a splendid show of physical power, and with desperate effort, he got himself to a stand with stiff-legged, sliding bounds along the shelf. Here he paused for a second, then stepped out of sight behind a rock point. Feeling that he must be crippled, I hurriedly scrambled up and out on a promontory from which to look down upon him. He was trotting down a slope without even the sign of a limp!