Of still more lowly habits are the ferns, mosses, and lichens which form a thick, luxuriant, and ever-varied carpet over the black humus soil beneath. The ground throughout the forest is encumbered with fallen trunks, sometimes piled one on another to the depth of 20 or 30 feet, which, owing to the continuous moisture, remain undecayed for centuries. Not infrequently a massive cedar or fir, in size and shape not unlike a prostrate column of some great temple, supports three or more trees, each large enough to be cut for lumber, whose gnarled and twisted roots clasp the sides of their host and descend to the earth beneath. The beauty of these fallen giants when overgrown with thick layers of variegated moss and exquisitely decorated with hundreds of small hemlocks and a multitude of gracefully bending fern-fronds, always fresh in colour and usually beaded with moisture, is beyond the power of the most skilful artist to adequately portray. The fascination of the great forest is such that the explorer, although perhaps weary with forcing a passage through the dense undergrowths and climbing over prostrate trunks, is lured by its charms into more and more inaccessible retreats probably never before invaded by man, but at last finding that the wonderland has no attainable limits, is content to rest on some inviting couch of golden-tinted lichens and study the varied charms and endless details of the dream-like picture surrounding him. From a commercial point of view the forest of the Puget Sound region is of immense importance. Lumber industries have been established there, with the most improved appliances for cutting trees, transporting the logs to mills, and sawing them into lumber, much of which is loaded on ships and widely distributed. So vast is the forest, however, that as yet the natural conditions are but slightly changed, except in the immediate vicinity of tide-water, but the destruction from axe and fire has only been begun; the waste that, no doubt, is to continue is most disheartening. Another centre in the vast and locally differentiated Pacific forest, as typical in its way as are the dense growths of fir and cedar just referred to, occurs on the Coast Range of north California, where the redwood (_Sequoia sempervirens_) is the all-important and characteristic tree. This redwood forest begins at the south in the vicinity of San Francisco, and extends northward, mainly on the moist seaward slopes of the Coast Ranges, to southwestern Oregon, but seldom reaches more than 30 miles inland. [Illustration: FIG. 30.--Redwood Forest, California.]