After about a half an hour of strenuous exertion, Tom found himself in the midst of an almost impassable jungle of tangled, stunted fir trees. He tried to avoid these by making a detour, but found that they extended so far that he could only pass them by going along close to the edge of the cliff. This last path he chose, and clinging to the branches, he passed for more than a hundred yards along the crest of a frightful precipice, where far down there yawned an abyss, at whose bottom was the sea; while abreast of him in the air there floated great flocks of gulls, uttering their hoarse yells, and fluttering fiercely about, as though trying to drive back this intruder upon their domains. Once or twice Tom was compelled to stop, and turn away his face from the abyss, and thrust himself in among the trees; but each time he regained his courage, after a little rest, and went on as before. At length he passed the thick spruce underbrush, and found the woods less dense. He could now work his way among them without being compelled to go so close to the edge of the cliff; and the dizzy height and the shrieks of the gulls no longer disturbed his senses. The trees here were not so high as those at the other end of the island, but were of much smaller size, and seemed stunted. There were no maples or other forest trees, but only scraggy fir, that seemed too exposed to the winds from the sea to have much health or verdure. The underbrush was wanting to a great extent, but moss was here in large quantities, and thick clusters of alder bushes. Wild shrubs also--such as raspberries and blueberries--were frequently met with; while ledges of weather-beaten rock jutted out from amid thick coverings of moss. Walking here was not at all difficult, and he went on without any interruption, until, at last, he found any farther progress barred by a precipice. He was at the lower or western end of the island. He looked down, and found beneath him a great precipice, while rocks jutted out from the sea, and ledges projected beyond. The gulls were present here, as elsewhere, in great flocks, and still kept up their noisy screams. Tom looked out over the sea, and saw its waters spread far away till it was lost in the horizon. On the line of that horizon he saw a faint gray cloud, that looked like a fog bank. It had, to his eyes, a certain gloomy menace, and seemed to say to him that he had not seen the last of it yet. On the left of the broad sea, the Nova Scotia Coast ran along till it was lost in the distance; and on the right was the long line of the New Brunswick shore, both of which had now that dark hue of olive green which he had noticed on the land opposite before he had started.