. Morphology of spermatophytes. [Part I. Gymnosperms]. Gymnosperms; Plant morphology. 84 MORPHOLOGY OF SPBRMATOPHYTES from the primary neck cell, and by periclinal divisions the single plate becomes two, so that the neck is composed of two tiers of cells with four cells in each tier. The recorded deviations are as follows: in Tsuga Canadensis, 31a, 49, and Cephalotaxus Fortunei the neck is usually two-celled, as in Cycads and Ginkgo; in some Cupresseae eight cells occur in each tier; while in some specis of Pinus and Picm more than two tiers of cells occur, with four or eight cells in each tie
. Morphology of spermatophytes. [Part I. Gymnosperms]. Gymnosperms; Plant morphology. 84 MORPHOLOGY OF SPBRMATOPHYTES from the primary neck cell, and by periclinal divisions the single plate becomes two, so that the neck is composed of two tiers of cells with four cells in each tier. The recorded deviations are as follows: in Tsuga Canadensis, 31a, 49, and Cephalotaxus Fortunei the neck is usually two-celled, as in Cycads and Ginkgo; in some Cupresseae eight cells occur in each tier; while in some specis of Pinus and Picm more than two tiers of cells occur, with four or eight cells in each tier. After the separation of the neck cell from the central cell, the latter begins a remarkable increase in size and receives a. ^x D Fig. 64.—JPinus Laricio: A, arohegonium initial, May 28th ; B^ neck and central cells, June 2cL; C, central cell just before cutting off the ventral canal cell, June 18th ; D, cutting oif of the ventral canal cell, June 21st; x 104. large amount of nutritive material (Fig. 64, C). About it a definite jacket of endosperm cells is organized, resembling the venter of an archegonium. The cells of the jacket become sur- charged with protoplasmic material, and their nuclei enlarge, while the wall of the central cell becomes thick and very dis- tinctly pitted. Through these pits Goroschankin ^® first traced a continuity of cytoplasm between central cell and jacket cells. Very early in its history, at the beginning of its enlargement, the central cell becomes vacuolate, the protoplasmic contents forming merely a wall layer, the nucleus retaining its apical position from. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Coulter, John Merle, 1851-1928; Chamberlain, Charles Joseph, b. 1863. New York, D. Appleton
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