MOSSES, Musa, an order of acotyledonous plants, consisting of mere cellular tissue without vessels, and distinguished from Hepatim (q.v.), the order with which they are most nearly allied, by having always a leafy stem, and an operculated capsule or urn (sporangium or theca), which opens at the top, and is filled with spores arranged around a central column (colamella). The capsule is covered by a hood (calyptra); and when it is ripe, and has thrown off the and operculum, exhibits around its mouth a single or double row of rigid processes, few or numerous, but always either four or a multiple of four, collectively called the peristome. These reproductive organs are viewed by many botanists as female flowers or whilst reproductive organs of another kind, sometimes found on the same plant, but more generally on distinct plants, are regarded as male flowers or antheridia, These are minute cylindrical sacs, occurring in the arils of the leaves, or collected into a head inclosed by variously modified leaves at the summit of the stem, and finally bursting and discharging a great number of spheri cal or oval resides, through the transparent walls of which, when moistened with water, filaments (Apernzatozdids) coiled up within them may be seen wheeling rapidly round and round. As the sacs merely discharge these vesicles and perish, it is supposed that the spermatozoids contained in them may effect the fertilization of the spore-producing cap sules; but this wants confirmation, and their particular office as reproductive organs is not yet fully ascertained.—None of the mosses are large plants, many are very small. Many have elongated stems, often branching; others have the stem scarcely developed, so that they Seel]] to consist of a mere tuft of leaves. They are generally social in their manner of growth. They are among the first plants which begin to clothe the surface of rocks, sands, trunks of trees, etc., adapting inorganic matter for the support of higher kinds of vegetation. They love moisture, and are generally more abundant in cold and
temperate than in hot climates. They struggle for existence on the utmost limits of vegetation in the polar regions and on mountain-tops. They dry up and appear as dead in a very dry state of the atmosphere. but revive when moisture returns. Some of them grow in bogs, which they gradually fill up and consolidate. They are of great use in pro tecting the roots of many plants from cold and from drought, and afford harbor to mul titudes of insects. Some of them supply food for cattle, particularly for the reindeer. when nothing better is to be obtained, and a wretched kind of bread is even made by some of the dwellers in the Arctic regions, of species of Sphagnum: Some are astrin gent and diuretic, but their medicinal virtues are unimportant. Among the other principal uses to which they are applied by man are the packing of things liable to he broken, the littering of cattle, the covering of garden plants in winter, and the stuffing of the open space in roofs to moderate the heat of attic rooms in summer and their cold in winter—perhaps the most important use to which they are ever put, at least in Britain, and 40 which, as the benefit is great and easily attained, it is wonderful that they are not much more frequently applied. The abundance of mosses in meadows and pastures. is disagreeable to farmers. The best remedies are proper drainage, the applica tion of lime, and the liberal use of other manures, by which the soil may be enriched, so that better plants may grow with sufficient luxuriance, upon which the mosses are choked and disappear. .
Several thousand Speelds_of mosses are known. Many of the mosses are very beauti ful, and their capsules and other organs are interesting objects of study, even with an ordinary magnifying-glass.