The forest at Locotál is somewhat taller than at Incachaca, but the birds are of a similar character. Very abundant and beautiful were the brilliant cocks-of-the-rock; the bright, orange-red creatures flashed through the deep green of the forest like fiery comets and, perching on the low branch of a tree, quietly surveyed their surrounding, or uttered hoarse, croaking calls. This bird is most conspicuous in its natural environment. Among the other large birds were green toucans (_Aulacorhynchus_); the natives hunted them on every possible occasion for the sake of obtaining the bill, which they use as _remedio_, the rasping sound made by rubbing the mandibles together being supposed to be an unfailing cure for epilepsy. While pursuing our work at Locotál, a man named Quiroga chanced to pass, and begged that we pay him the honor of stopping at his house some distance below; it was a charming place, he said, in the very heart of the wonderful Yungas. We gladly accepted his invitation, and one morning loaded our outfit on mules and started down the trail. For a mile there is only a narrow ledge in the face of a rounded mountain of dark sandstone; a few stunted sprouts, and myriads of orchids covered with purple blooms, have secured a precarious foothold in crevices in the glazed surface; hundreds of feet below, but invisible, the river tears through a narrow gorge. At one point a strip of the shelf upon which we travelled had entirely disappeared; we could not see the bottom of the canyon--its depth was too great--but there were evidences we could not mistake, telling us the history of the gap in the trail. Vultures hovered over the spot and perched on the scant vegetation, and from below came an overpowering stench. What more was needed to reveal the fact that the missing section of trail, in its mad dash through space, had taken with it the pack-train of mules, and probably the men attending them, which chanced to be passing at the time. Miguelito is only three miles below Locotál, and consists of three or four huts in the centre of a grassy clearing. The Quechuas who live there are friendly, and one may be sure of a welcome for a night’s stop. At five thousand five hundred feet the forest becomes taller and the trees attain a greater diameter. The vegetation of the subtropic zone reaches its highest development at this altitude. After crossing a ridge six thousand seven hundred feet high, the trail descends a long slope into the Yungas, properly known as the Yungas of Cochabamba. At the base of the ridge, and shortly before entering the cultivated area, we crossed the dry, narrow bed of a stream which was filled with rocks bearing the imprints of leaves, and also fossil shells.