It was his idea to establish firmly in mind the trend of the mountain-range, and the relation of the river to it. The difficulty in mapping the river would come after it left the mountains to wind away into the wide lowlands. The matter of climbing the bluff would have been easy but for the fact that he wished to avoid contact with grass, brush, trees, even dead branches, as all were covered with ticks. The upper half of the bluff was bare, and when he reached that part he soon surmounted it. Ken faced south with something of eagerness. Fortunately the mist had dissolved under the warm rays of the sun, affording an unobstructed view. That scene was wild and haunting, yet different from what his fancy had pictured. The great expanse of jungle was gray, the green line of cypress, palm, and bamboo following the southward course of the river. The mountain-range some ten miles distant sloped to the south and faded away in the haze. The river disappeared in rich dark verdure, and but for it, which afforded a water-road back to civilization, Ken would have been lost in a dense gray-green overgrowth of tropical wilderness. Once or twice he thought he caught the faint roar of a waterfall on the morning breeze, yet could not be sure, and he returned toward camp with a sober appreciation of the difficulty of his enterprise and a more thrilling sense of its hazard and charm. “Didn’t see anything to peg at, eh?” greeted Hal. “Well, get your teeth in some of this venison before it’s all gone.” Soon they were under way again, Pepe strong and willing at the oars. This time Ken had his rifle and shotgun close at hand, ready for use. Half a mile below, the river, running still and deep, entered a shaded waterway so narrow that in places the branches of wide-spreading and leaning cypresses met and intertwined their moss-fringed foliage. This lane was a paradise for birds, that ranged from huge speckled cranes, six feet high, to little yellow birds almost too small to see.