1552. The second order, or the Vascular mosses corresponds to the sheaths, or to the Hyphomycetes. They are long filaments replete with granules, growing in water, and therefore green—Confervaceæ. These plants begin to ramify, and either increase by this means or by effusion of granular matter.
1553. The third order, that of the Tracheal mosses, corresponds to the stem, or to the Gasteromycetes. A membranous trunk originates in water, which in certain places secretes the seeds in special vesicles or cysts—Fucales or connate Confervæ. The fuci have at once the form of a stalk with root and leaves, because they correspond to these three organs of the axis.
1554. The fourth order, the Floral mosses, endeavours to obtain the blossom, and therefore elevates itself out of the water, but loses on that account the trunk-like character, and exhibits for the most part only membranous expansions, upon which seeds are secreted, which being usually of a beautiful colour, thus assume the appearance of corollæ—Lichenales. The lichens are fuci in dry situations. They correspond to the Pyrenomycetes or Sphæriaceæ.
1555. As the variegated colours appear in the blossom, so do they also in the lichens; but here they are for the first time chemically developed, distributed throughout the whole substance, and concealed. Most lichens yield colouring matters.
1556. As the stem is, in accordance with their signification, wanting to the lichens, they thus require a foreign trunk for their nutrition. They are therefore developed for the most part upon other plants, and principally upon the bark.
1557. Lastly, the fifth order, Fruit-mosses, originates through the development of a self-substantial fruit upon a cauliform stem—the Mosses proper.
1558. As these are the highest plants of this class, and those that directly precede the tracheal formation, so the bark already resolves itself into individual leaves, which are, however, still destitute of spiral vessels.
1559. What have been called the seeds or sporules are accumulated in a capsule-like fruit upon the summit of the stalk. This fruit corresponds to the pileated fungus, and therefore springs up in an opercular manner like the latter.
1560. But this capsule is only a spermoderm, which incloses albuminous granules that have no proper germ or seed-lobes; they are plants with seed-vessels or pyxidia, upon an open-leaved stalk.
1561. They divide likewise into sixteen families. (Vid. Tab. B.)