Page:Evolution of Life (Henry Cadwalader Chapman, 1873).djvu/126

90 (Fig. 120, A), inside of which will be found the embryo-cell (Fig. 120, B). The embryo-cell, after the contact of the spiral filament, is changed into the Sporangium, or case which contains the spores, from which the new plant will be developed.

The Hepaticae, or Liverworts, seem to be transitional plants, leading up from the Green Algae and Characeae to the Mosses and Ferns, they representing, probably, the common stem from which the roots of the Mosses and Ferns have diverged.

The beautiful green velvety carpeting of woods commonly known as Mosses (Figs. 118, 119), growing most luxuriantly in damp, shady places, so useful from freely absorbing and retaining moisture, to be given out in time of drought, is made up of small delicate plants, each individual consisting of a stem and leaves, exhibiting under a low magnifying power a great variety and beauty of form. While Mosses, in the arrangement of their stem and leaves, differ greatly from the Jungermanniae, one group of them, the Hypoterygiae (Fig. 117) furnish perfectly the transition; the erect stem and leaves of the Hypoterygiae agreeing in structure with the procumbent one of Jungermanniae. The reproductive apparatus of the Hypoterygiae, however, is like that of Mosses generally. This consists, as in Hepaticae, of Archegonia and Antheridia. The Archegonia are flask-shaped bodies containing the embryo-cell. The Antheridia (Fig. 120, C) are oval cellular bodies, having inside the spiral filament. (Fig. 120, D.) The embryo-cell (Fig. 120, B), by the contact of the spiral filament, is changed in Mosses, however, into a stalk supporting an urn-shaped body. In this urn are produced the spores, which do not at once reproduce the new Moss, but protrude a confervoid growth, the so-called Protonema, a structure very like that