Plants and their ways in South Africa . .—Longitudinal section through the sporophyte of Pellia epiphylla^R, rhizoids ; I, involucre ; F, foot of sporophyte ; Se, seta ; C, capsule ; of capsule ; Wa, wall of archegonium ; S, spores ; N, remains of neck ofarchegonium ; A, unfertilized archegonium (highly magnified). (From Evans Intermediate Text Book of Botany.) are the fern spores, contained within clusters of spore-casesforming the dots. A dot is called a sorus (plural, sori).When the spores are ripe and have fallen in moist places, theyburst their brown walls and begin to grow. In a f
Plants and their ways in South Africa . .—Longitudinal section through the sporophyte of Pellia epiphylla^R, rhizoids ; I, involucre ; F, foot of sporophyte ; Se, seta ; C, capsule ; of capsule ; Wa, wall of archegonium ; S, spores ; N, remains of neck ofarchegonium ; A, unfertilized archegonium (highly magnified). (From Evans Intermediate Text Book of Botany.) are the fern spores, contained within clusters of spore-casesforming the dots. A dot is called a sorus (plural, sori).When the spores are ripe and have fallen in moist places, theyburst their brown walls and begin to grow. In a few weeks aspore will grow into a filmy, green, heart-shaped plant. Lookunder the shelves of greenhouses or on the outside of pots inwhich ferns are growing. They are often abundant call them Moss, but we know that moss leaves areborne on stems. Each one of these plants grows by itself. How Does the Fern Plant Come ?—On the under sideof the plants which are called prothallia are rhizoids and Classification of Plants 231. Fig. 205, l.—Equisetum sylvaticum /a, a. fertile shoot, not containing chloro-phyll, bearing the sporangia at its summit; 3, a fertile green shoot ; betweenthese a sterile green shoot (reduced) ; these three kinds of shoots do not alwaysoccur. 232 Plants and their Ways in South Africa two kinds of sexual organs, resembling those in the liverwortand the moss. Archegonia containing the germ- or egg-cellsare near the notch in the prothallium; antheridia containingthe sperm-cells are down near the point among the sperm-cell swims into the archegonium, unites with thegerm-cell, and then the germ-cell grows into a leafy fernplant, just as the stalked capsule of the moss grew out of thepockets hidden among the leaves. The fern plant, though,forms roots and can soon take care of itself,while the moss capsule always depends uponthe leafy part for its food. In the liverworts,mosses, and ferns, the germ-cell has to swimto reach its sperm-cell,
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectplants, bookyear1915
