This knowledge clearly pointed out to David the course he had to follow. And early the following morning found him prepared to extend his trail or open a new one. He carried his pail, as usual; in addition, the long-handled ax for tapping the new trees. His revolver and knife were in his belt. When he reached the end of the trail he put down the pail and continued walking through the forest; the country was all new to him, but he had no difficulty in locating rubber trees. They seemed more plentiful than ever, if anything. Clumps of them stood among the palms and other tall growths. As he penetrated farther and farther into the thick jungle he snapped or turned twigs every few steps so that there would be no trouble in finding his way back. He had been travelling in this manner more or less steadily for the greater part of two hours and had covered a distance of three or four miles. No less than two hundred new trees had been added to his line; when they produced freely, as they would within a week, his daily catch would compare favorably with that of the best in spite of the depredations of the woodhewers. To one side of him grew a very tall tree, towering high above its fellows; the trunk was straight and about four feet through, and David estimated that the lowest limb was fully sixty feet above the ground while the topmost twigs must have been a hundred and fifty feet above his head. There were numbers of round objects hanging from the branches. He wondered what they were, and thinking that some of them might have fallen to the ground he walked to the tree to see if he could find one. Before long he found one of the large, cannon-ball-like objects, and upon breaking it open found a number of Brazil nuts inside. He stooped to crack one, but the blows from his knife never fell; from directly above him came the most peculiar song he had ever heard. It rose clear and ringing, setting the jungle a-tingle with its resonance, and swelling airily and easily until it seemed to penetrate the body of the listener. _Oo-whee whee-e-e oo_ came the song, first low and plaintive, then rising to a very loud yet mellow pitch and again descending to the low, sad _oo_, finally ending in a few almost inaudible _churrs_. It sounded somewhat like the ringing of a bell. Now, David had read about the bell birds of the South American forest and he felt that this must be one of them. Without rising, his eyes searched the branches overhead. The notes had come from so close at hand that the singer must have been in one of the lower growths, almost within reach of the man’s hand.