. Plant studies; an elementary botany. Botany. BEYOPHYTES 305. globular body (Figs. 277, 278). A section through this body shows it to consist of a single layer of cells, which forms the wall of the antheridium, and within this a compact mass of small cubical (square in section) cells, within each one of which there is formed a single sperm (Fig. 278). The sperm is a very small cell with two long cilia (Fig. 277). These small biciliate sperms are one of the distinguishing marks of the Bryophytes. When the mature antheridia are wet they are opened at the apex and discharge their contents (Fig.
. Plant studies; an elementary botany. Botany. BEYOPHYTES 305. globular body (Figs. 277, 278). A section through this body shows it to consist of a single layer of cells, which forms the wall of the antheridium, and within this a compact mass of small cubical (square in section) cells, within each one of which there is formed a single sperm (Fig. 278). The sperm is a very small cell with two long cilia (Fig. 277). These small biciliate sperms are one of the distinguishing marks of the Bryophytes. When the mature antheridia are wet they are opened at the apex and discharge their contents (Fig. 277), and the sperms escaping swim actively about. 199. The archegonium.—This name is given to the female sex organ, which is a many-celled structure, shaped like a flask (Figs. 277, 287). The neck of the flask is more or less elongated, and within the bulbous base (venter) the single egg is organized. To this neck the swimming sperms are attracted, enter and pass down it, one of them fuses with the egg, and this act of fertilization results in an oospore. 200. Germination of the oospore.—The oospore in Bryo- phytes is not a resting spore, but germinates immediately by cell division, forming the sporophyte embryo, which presently develops into the mature sporophyte (Fig. 279, A). The lower part of the embryo develops the foot, which obtains a firm anchorage in the gametophore by the latter growing up around it (Fig. 279, B, C). The upper part of the embryo develops upward, organizing the seta and cap- sule. As the embryo increases in size, the venter of the archegonium grows also, forming what is called the calyptra; and in true mosses the embryo presently breaks loose the calyptra at its base and carries it upward perched on the top Fig. 278. Antheridium of a liverwort in section, showing single layer of wall cells surround- ing the mass of moth- er cells.—After Stras- Please note that these images are extracted from scanned page images that may have been digita
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