Text-book of botany, morphological and physiological . certain time the mother-cells of the spores swim inthe fluid which fills the cavity of the sporangium; according to their mode of formationthey form groups of two or four sister-cells (Fig. 10, a, b). Each mother-cell consists atfirst of a large spherical nucleus (including nucleoli), surrounded by fine-grained turbidprotoplasm, which has a sharply defined contour, but is without a cell-wall. Dilutealcoholic solution of iodine, and other substances which cause contraction, show thisvery definitely; with the contraction of the protoplasmic
Text-book of botany, morphological and physiological . certain time the mother-cells of the spores swim inthe fluid which fills the cavity of the sporangium; according to their mode of formationthey form groups of two or four sister-cells (Fig. 10, a, b). Each mother-cell consists atfirst of a large spherical nucleus (including nucleoli), surrounded by fine-grained turbidprotoplasm, which has a sharply defined contour, but is without a cell-wall. Dilutealcoholic solution of iodine, and other substances which cause contraction, show thisvery definitely; with the contraction of the protoplasmic body of the mother-cell notthe very finest trace of membrane becomes visible in any state of division. The firstpreparation for the division of the mother-cell is manifested by the clarifying of theprotoplasm {b), by the gathering of a group of greenish-yellow granules on theside of the nucleus which lies next the sister-cell; then the nucleus disappears, and thegranules arrange themselves in the form of a disc, which passes through the centre of the. Fig. 9 —Zoosporangiaof an Achlya(X550).A still closed, B allowing the zoospores toescape, beneath it a lateral shoot c; a thezoospores just escaped ; 6 the abandonedmembranes of the zoospores which havealready swarmed; e swarming zoospores. 14 MORPHOLOGY OF THE CELL. spherically-formed mother-cell (c); the protoplasm thus becomes perfectly free fromgranules, and as transparent as a drop of oil; but soon a turbidity again sets in to the rightand left of the disc of granules; fine granules appear at both pdles of the mother-cell, and spread further and further, until at last onlya clear ellipsoidal space remains right andleft (e), these spots free from granules aretwo nuclei; the disc of granules begins toshift its position; the two large ellipsoidalnuclei again disappear; and in their placeappear four smaller ones (/), arranged inthe angles of a tetrahedron, each of whichis surrounded on the side facing its neigh-bours by a porti
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectbotany, bookyear1875
