. Plants and their uses; an introduction to botany . vegetative branch at the base, ^,. F, .same, with many pseudo-leaves removed to show the male gametangia (antheridia), . G, anopened and empty antheridium, ajo. H, five cells containing youngspermatozoids, ?•?;«. J, such a cell nearly ripe, ja. K, spermatozoid,^^. L, ripe fruit (sporophyte) with remains of the archogonium atits base borne on a stalk continuing the axis of the whichbears psoido-leaves at its base; magnified. (Schimper.) THE TRUE MOSSES 525 moss-branches above (Fig. 347). In either case these vertical pseudo-leafy
. Plants and their uses; an introduction to botany . vegetative branch at the base, ^,. F, .same, with many pseudo-leaves removed to show the male gametangia (antheridia), . G, anopened and empty antheridium, ajo. H, five cells containing youngspermatozoids, ?•?;«. J, such a cell nearly ripe, ja. K, spermatozoid,^^. L, ripe fruit (sporophyte) with remains of the archogonium atits base borne on a stalk continuing the axis of the whichbears psoido-leaves at its base; magnified. (Schimper.) THE TRUE MOSSES 525 moss-branches above (Fig. 347). In either case these vertical pseudo-leafy shoots are homologous with the ascending branches of Mar-rhantia; but as seen in Fig. 348 they are much more elaboratelyconstructed. At the surface of the stem are developed usuallyseveral layers of large cells with very thin walls which are kept fromcollapsing by ridge-like thickenings, and communicate with oneanother and with the exterior by pores (D) of considerable cells soon lose their protoplasm and then form a sponge-like. Fig. 349.—Peat mosses. A, tip of female branch of S. acutifolium, cutvertically to show the archegonia (ar), protective leaves (c/i) stillyouug, and older ones {y) acting like bud-scales. B, young fruit,cut vertically to show the sporophyte of which the foot {sg) is fixedin the head («) of the stalk or pseudopodium (ps), and the spore-case(sg) IS still enveloped by the calyptra (c) bearing above the old neck (ar)of the archegonium. C, ripe sporophvte of S. squarrosuni, showing itslid (d) and spore-case (sg) emerged from the torn calyptra (c) and borneupon a pseudopodium pushing it beyond the formerly protectingpseudo-leaves (ch). All magnified. (Schimper.) or wick-like envelope which draws water from below by capillarity,and stores it ready for use. The pseudo-stem is strengthened by auniform thickening of the walls of an inner c^ylinder of cells. Thepseudo-leaves are made up chiefly of large, thin-walled cells (B)like the outer cells
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1913
