. Elements of botany. Botany. Fig. V22. Pollen Grains producing Tubes, on Stigma of a Lily. (Much magnified.) g, pollen grains; t, i^olleu tubes; p, papilhe of stigma; c, canal or passage running toward ovary. Fio. 123. Germination of I'oUen Grain of an Angiosperni. (Much magnified and somewhat dia- grammatic.) A, entire grain, with germination con- siderahly advanced. Ji, tip of pollen tube at a much later stage, after the tube nucleus has disappeared: g, the generative cell l)eginning to enter the tube; t, the tube nucleus; s, sperm cells formed from the generative cell. which contains mater
. Elements of botany. Botany. Fig. V22. Pollen Grains producing Tubes, on Stigma of a Lily. (Much magnified.) g, pollen grains; t, i^olleu tubes; p, papilhe of stigma; c, canal or passage running toward ovary. Fio. 123. Germination of I'oUen Grain of an Angiosperni. (Much magnified and somewhat dia- grammatic.) A, entire grain, with germination con- siderahly advanced. Ji, tip of pollen tube at a much later stage, after the tube nucleus has disappeared: g, the generative cell l)eginning to enter the tube; t, the tube nucleus; s, sperm cells formed from the generative cell. 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 iinother plant of the same kind, not from the indi- vidual which bears the ovirles that are being fertilized. Pollen tubes begin to form soon after f)ollen 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, bookyear1904
