. Plant studies; an elementary botany. Botany. BUYdPllM'KS 305. £jlolral:ir lioily (Figs. 377, 378). A section tlirongli this body shows it to consist of a single layer of cells, which forms the wall of the antheridiuiii, ami within this a comjiact mass of small euljical (square in section) cells, within each one of which there is formed a single sperm (Fig. 37S). The sperm is a very snudl cell with two long cilia ( Fig. 377). These small biciliate sperms are one of the distinguishing marks of the Bryophytes. When the mature antheridia are wet they are ruptured at the apex and discharge their
. Plant studies; an elementary botany. Botany. BUYdPllM'KS 305. £jlolral:ir lioily (Figs. 377, 378). A section tlirongli this body shows it to consist of a single layer of cells, which forms the wall of the antheridiuiii, ami within this a comjiact mass of small euljical (square in section) cells, within each one of which there is formed a single sperm (Fig. 37S). The sperm is a very snudl cell with two long cilia ( Fig. 377). These small biciliate sperms are one of the distinguishing marks of the Bryophytes. When the mature antheridia are wet they are ruptured at the apex and discharge their contents (Fig. 277), and the sperms escaping swim actively about. I'M. The archegonium.—This name is given to the female sex organ, which is a many-celled structure, shaped like a flask (Figs. 377, 3S7). The neck of the flask is more or less elongated, and within the bulbous base (renter) the single egg is organized. To this neck the swimming s}ierms are attracted, enter and pass down it, one of them fuses with the l'i:'^, and this act of fertilization results in an oospore. 300. Germination of the oospore.—The oospore in I5ryo- plivtes is not a resting spore, germinates immediately liv cell division, forming the sporophyte embryo, which l^resently develops into the mature sporophyte (Fig. 379, A). The lower part of the emliryo develops downward into the gametophore, forming the foot, Avhich penetrates and ob- tains a firm anchorage in the gametophore (Fig. 370, /?, ('). The upper 2iart of the embryo develops upward, organizing the seta and capsule. In ti'uc flosses, when the embryo becomes too large for the venter of the archegonium in which it is developing, the archegonium is Ijroken near the base of the venter and is carried upward perched on tlie top ;. i;78. .-VntlR-fidiiim of a lix'Crwnrt in section, bhowiiiL,' siiii^le layer rif wall cells surround- inir the mass of moth- er cells.—After Please note that these images are extracted from scan
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectbotany, bookyear1900
