To Jack and Fred he seemed fully four times the size of the largest black bear they had ever seen in any zoological garden. Had his legs been longer, Fred Greenwood would have pronounced him the equal of Jumbo himself. Where this Colossus among beasts had come from it was impossible to say, but the terrifying fact was self-evident that he was advancing to attack the boys! He must have caught sight of them as they sat on the rock with their backs toward him, and, angered at the intrusion, he was sweeping down upon them like a cyclone, furious and determined to crush them out of existence. [Illustration: "He was sweeping down upon them like a cyclone."] The gait of the animal was awkward, but speedier even than the youths suspected. He swung along with a swaying motion, and his claws, striking the flinty rocks as he passed over them, rattled like iron nails. His vast mouth was open, his long red tongue lolling out, and his white teeth gleaming. As if no element of terror was to be omitted he uttered a deep, cavernous growl at every step or two, while his comparatively small black eyes seemed to glow with a savage light, altogether foreign to the species. All this was taken in at the first glance of the boys, who, petrified for one moment, realized in the next their fearful peril. "There's no time to shoot!" exclaimed Jack; "we must run!" "But he can run faster than we!" replied Fred, who stood his ground long enough to bring his Winchester to his shoulder and let fly straight at the front of the beast. That he struck the bear was certain, but it served only to add to his towering rage, and he plunged forward without halt. Jack had made no attempt to fire, but was running at headlong speed. Fred was eager to thrust another cartridge into the chamber of his Winchester from the magazine, but to do so would detain him until old Ephraim was upon him, and even then it was not likely the bullet would stay or affect his attack. Accordingly, instead of firing a second shot he whirled about and dashed after Jack, who was thus placed about a rod in advance. Although the ground was not favorable for running, it may be safely said that neither Jack Dudley nor Fred Greenwood ever gave such an exhibition of speed. They held fast to their rifles, for it looked as if the weapons were to be their final reliance. Fred glanced over his shoulder to learn how he was making out in the race. With an awful sinking he saw that the grizzly was gaining fast upon him. Still he dared not pause long enough to fire, but redoubled his energies, only to catch his foot in a running vine and plunge forward on his face. CHAPTER XII. THE TUG OF WAR.