. Essentials of botany. Botany; Botany. Fig. 123. Germination of Pollen Grain of an Angiosperm. (JIuch magnified and somewhat dia- grammatic.) -1, entire grain, with germination con- siderably advanced. B, tip of pollen tube at a much later stage, after the tube nucleus has disappeared: g, the generative cell beginning to enter the tube; t, the tube nucleus; s, sperm cells formed from the generative cell. Fig. 122. Pollen Grains producing Tubes, on Stigma of a Lily. (JIuch magnified.) g, pollen grains; t, pollen tubes; p, papillse of stigma; c, canal or passage running toward ovary. which cont
. Essentials of botany. Botany; Botany. Fig. 123. Germination of Pollen Grain of an Angiosperm. (JIuch magnified and somewhat dia- grammatic.) -1, entire grain, with germination con- siderably advanced. B, tip of pollen tube at a much later stage, after the tube nucleus has disappeared: g, the generative cell beginning to enter the tube; t, the tube nucleus; s, sperm cells formed from the generative cell. Fig. 122. Pollen Grains producing Tubes, on Stigma of a Lily. (JIuch magnified.) g, pollen grains; t, pollen tubes; p, papillse of stigma; c, canal or passage running toward ovary. which contains material derived from the pollen and from the egg-cell. In a great many plants the pollen, in order to accomplish the most successful fertilization, must come from another plant of the same kind, not from the indi- vidual which bears the ovules that are being fertilized. Pollen tubes begin to form soon after pollen grains lodge on the stigma. The time required for the tube to penetrate to the ovary varies in different kinds of plants. Finally the tube enters the opening at the apex of the. 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 Bergen, Joseph Y. (Joseph Young), 1851-1917. Boston, Ginn
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectbotany, bookyear1908
