Now, upon the lower slopes, it led through dense forests where the ground was so matted with fallen trees and over-rioting vines and brush that the way held always to the swaying branches high above the tangle; again it skirted yawning gorges whose slippery-faced rocks gave but momentary foothold even to the bare feet that lightly touched them as the three leaped chamois-like from one precarious foothold to the next.