For two or three minutes nothing happened, and the wolves continued to walk around the bunch. Then, suddenly, one of them made a dash at the bunch of cattle, going so close to them that Jack expected to see the wolf caught on a steer's horns and thrown into the air. When the wolf rushed up, the bunch of cattle seemed to tremble; that is to say, there was apparently a slight movement by every individual in the herd, and Jack recalled similar movements which he had seen years before in British Columbia among a school of salmon far below the surface of the water, when some one darted down toward the fish a spear which nearly reached them. It seemed to him that every animal yielded a little, yet no one of them perhaps moved more than six or eight inches. A moment or two later one of the wolves made another rush, which was followed by a similar slight movement of the bunch; and then the wolves continued their slow march about the cattle. This happened several times, but at last when the wolf dashed toward the bunch, one animal--a full-grown one--burst out of the herd and started to run. In an instant the wolf was behind it, between it and the other cattle; and a moment later the second wolf had joined the first one, and they loped quietly along after the single animal. Presently, running side by side, they drew up close to its heels, and then, separating, one of them made a vicious snap at the cow's leg while the other sprang and caught it in the flank; and in an instant, too quickly for Jack to see how it was done, the beast was on its side and the wolves were tearing at its belly. Jack jumped to his horse and rode over the ridge, charging down toward the wolves. They paid no attention to him until he was within less than a hundred yards, and then, suddenly looking up, they galloped away. He fired four or five shots after them, but without result. The animal that they had pulled down was a two-year-old heifer, big, strong and fat. Her whole flank was torn out, and she was dead. There was nothing to be done with her. The brand was not one with which Jack was familiar, and he thought she was a stray from some distant ranch. He drove the remaining cattle slowly toward camp, and after a time met some of the other boys bringing in another bunch, and turned his in with theirs. That night, after supper, he talked with Hugh about the wolves and the harm they did, and also about the tremendous power that seemed to be wrapped up in one of those not very large hides. Hugh had seen wolves pull down cattle, and had a great respect for the way in which these animals were able to supply themselves with food.