Nearly every tree was well covered with lichens and moss and I could not see that these growths were any thicker on one side than the other. I was about to abandon this scheme for determining direction when I made a discovery. Glancing up and down the trunks in search of the moss growths, I noticed that one side of every tree was dark-colored and damp, whereas the other side was grayish and drier, and the damp side I soon found corresponded to the north as determined by my glimpse of the sun above the river. I was quite elated by this and I now noticed that the mosses _did_ appear heavier and more luxuriant on the damp side of the trees than on the dry side. A further scrutiny and comparison of the various trees also convinced me that the branches, twigs, and leaves were thicker and more regular on the south side of the trees than on the north, and that more dried and dead branches and stubs projected from the north side of the trees than from the south side. Fixing these facts in my mind, I determined to test my discoveries by actual experiment, and without looking at the tree trunks I wandered aimlessly ahead for several hundred yards. Then, closing my eyes, I walked slowly about for some time, bumping into numerous trees and tripping over fallen branches several times—until I felt that I had lost all sense of direction. Then, opening my eyes, I looked about. I was out of sight or sound of the river, the only signs of sunshine were faint, bright patches amid the lofty foliage of the trees, and nothing was in view which seemed familiar. For a moment my heart thumped and I shuddered to think what might happen if my signs failed and I could not find my way back to the river. It was a dangerous experiment, the peril of which I did not fully realize even then, but, pulling myself together, I focused my attention on the trees about me. There was no question about it, scarcely a glance was needed to show me which side of the trees faced the north and which the south, and, knowing that the river flowed to the east of the woods wherein I stood, I turned and started to retrace my steps. Even as I did so I realized how important was my newly acquired knowledge of this feature of woodcraft, for the direction which I had felt sure would lead me toward the river was _exactly opposite_ to that which was shown to be right by the trees.