Symbols in this passage?

What are all the symbols in this passage from chapter 16.

Thus conversing, they entered sufficiently deep into the wood to secure themselves from the observation of any casual passenger along the forest-track. Here they sat down on a luxuriant heap of moss; which, at some epoch of the preceding century, had been a gigantic pine, with its roots and trunk in the darksome shade, and its head aloft in the upper atmosphere. It was a little dell where they had seated themselves, with a leaf-strewn bank rising gently on either side, and a brook flowing through the midst, over a bed of fallen and drowned leaves. The trees impending over it had flung down great branches, from time to time, which choked up the current, and compelled it to form eddies and black depths at some points; while, in its swifter and livelier passages, there appeared a channel-way of pebbles, and brown, sparkling sand. Letting the eyes follow along the course of the stream, they could catch the reflected light from its water, at some short distance within the forest, but soon lost all traces of it amid the bewilderment of tree-trunks and underbrush, and here and there a huge rock, covered over with gray lichens. All these giant trees and boulders of granite seemed intent on making a mystery of the course of this small brook; fearing, perhaps, that, with its never-ceasing loquacity, it should whisper tales out of the heart of the old forest whence it flowed, or mirror its revelations on the smooth surface of a pool. Continually, indeed, as it stole onward, the streamlet kept up a babble, kind, quiet, soothing, but melancholy, like the voice of a young child that was spending its infancy without playfulness, and knew not how to be merry among sad acquaintance and events of sombre hue.