The Sphagnum moss has such a power of absorbing moisture from the atmosphere, that it forms and maintains the peat mosses and quagmires in the mountains which feed the streams at their feet. Mosses in general are almost as much indebted for moisture to the absorbing nature of their leaves as to their roots; but the loose, large celled, and perforated leaves of the Sphagnum suck up water like a sponge; even during the heat of summer, a quantity of water may be squeezed out of a handful of them. In fact the plant is a perfect hydraulic machine, for a small stem of it put into a glass of water with its drooping terminal branch hanging over the edge, acts like a syphon, and soon empties the glass, pouring the water out through its bending top. Though the peat from Sphagnum is often too spongy for fuel at present, yet that little moss now growing on our mountains will yield aniline, magenta, paraffin, and other illuminating gases to remote generations, although not in such quantities as the richer vegetation of the coal measures, the products of a warmer period. Like all cryptogams the mosses are exceedingly variable and difficult to distinguish. Not only does the same species show great differences in size, but even in other respects the characters vary on account of climate, soil, and exposure. Beyond that of becoming converted into peat, the uses of the moss family are not of any great importance. Brooms, mats, and other domestic articles are sometimes formed from Polytrichum, and in Lapland Sphagnum not only sometimes enters into the composition of bread, but is used in place of clothing for new-born babes. SECTION VIII. FILICES, OR FERNS.