. Botany; principles and problems. Botany. THE SPERM A TOP 11Y TA 345. 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 work.. Sinnott, Edmund Ware, 1888-. New York, McGraw-Hill
RMRH8WDN. Botany; principles and problems. Botany. THE SPERM A TOP 11Y TA 345. 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 work.. Sinnott, Edmund Ware, 1888-. New York, McGraw-Hill
. Botany; principles and problems. Botany. TIIR SPERM A TOPJI VTA 359 tive corolla, composed of petals; its pollen-producing stamens, and its ovule-bearing pistil. The pistil may be a single carpel (which has grown about the ovules and enclosed them); a number of. /-^ r J • •. 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 work.. Sinnott, Edmund Ware, 1888-. New York, McGraw-Hill
RMRH8W75. Botany; principles and problems. Botany. TIIR SPERM A TOPJI VTA 359 tive corolla, composed of petals; its pollen-producing stamens, and its ovule-bearing pistil. The pistil may be a single carpel (which has grown about the ovules and enclosed them); a number of. /-^ r J • •. 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 work.. Sinnott, Edmund Ware, 1888-. New York, McGraw-Hill
. Botany; principles and problems. Botany. THE SPERM A TOPII VTA 347 structure (the stigma) which is nearby. Since the egg cells are buried in the nuccllar tissue, it is evident that the male gametes cannot approach them directly, as in the lower plants, and a new structure has accordingly been developed which conveys them to the egg. This is the pollen-tube. It arises from the pollen-grain as a slender, thin-walled projection and into it the contents of the gi'ain passes, led by the tube-nucleus.. Fig. 218.—Development of the male gametophyte in a gymnosperm (Pine). A, longitudinal section (d
RMRH8WCJ. Botany; principles and problems. Botany. THE SPERM A TOPII VTA 347 structure (the stigma) which is nearby. Since the egg cells are buried in the nuccllar tissue, it is evident that the male gametes cannot approach them directly, as in the lower plants, and a new structure has accordingly been developed which conveys them to the egg. This is the pollen-tube. It arises from the pollen-grain as a slender, thin-walled projection and into it the contents of the gi'ain passes, led by the tube-nucleus.. Fig. 218.—Development of the male gametophyte in a gymnosperm (Pine). A, longitudinal section (d
. Botany; principles and problems. Botany. THE SPERM A TOI'IIYTA 353 As its name implies, the reproductive structures in this order are typically produced in cones. The microsporangial (staminate or "male") cones (Fig. 223) are short-lived and somewhat delicate structures, and each cone-scale (stamen or microsporo- phyll) bears two (rarely more) microsporangia on its lower or dorsal surface, in which the microspores or pollen grains are. Fig. 224.—Ovulate or "female" cones of the pine. developed (Fig. 218). The pollen is in all cases transferred to the ovules by wind. Excep
RMRH8WAG. Botany; principles and problems. Botany. THE SPERM A TOI'IIYTA 353 As its name implies, the reproductive structures in this order are typically produced in cones. The microsporangial (staminate or "male") cones (Fig. 223) are short-lived and somewhat delicate structures, and each cone-scale (stamen or microsporo- phyll) bears two (rarely more) microsporangia on its lower or dorsal surface, in which the microspores or pollen grains are. Fig. 224.—Ovulate or "female" cones of the pine. developed (Fig. 218). The pollen is in all cases transferred to the ovules by wind. Excep