. The algae. Algae. Fig. Ii6 Himanthalia lorea. A, fertile plant. B, C, abnormal buttons. D, button from bottom of dense zone. E, button from top of dense zone. F, apical cell. G, behind apex of young receptacle. m=meristoderm; cells recently cut off from it; =outer cortex; =inner cortex; m =medulla; p =pit. H-K, stages in elongation of medullary cells ( x 125). L, mature mega- sporangium (oogonium). (A-E, I, after Gibb; F-H, after Naylor.) the extremely elongated cells of the medulla may take on an ap- pearance resembling the trumpet hyphae of Laminaria. This may be
. The algae. Algae. Fig. Ii6 Himanthalia lorea. A, fertile plant. B, C, abnormal buttons. D, button from bottom of dense zone. E, button from top of dense zone. F, apical cell. G, behind apex of young receptacle. m=meristoderm; cells recently cut off from it; =outer cortex; =inner cortex; m =medulla; p =pit. H-K, stages in elongation of medullary cells ( x 125). L, mature mega- sporangium (oogonium). (A-E, I, after Gibb; F-H, after Naylor.) the extremely elongated cells of the medulla may take on an ap- pearance resembling the trumpet hyphae of Laminaria. This may be a case of parallel development, but in view of other similarities to Durvillea it may be suggested that Himanthalia represents a primitive though somewhat speciaUzed member of the Fucales. Reduction has proceeded so far in this genus that only one ovum matures in the ripe oogonium (macrosporangium). Liberation of gametes is controlled by the tides and exposure, and there is a definite periodicity related to these two factors. 207. 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 Chapman, V. J. (Valentine Jackson), 1910-. London, Macmillan; New York, St. Martin's Press
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Keywords: ., bo, bookcentury1900, bookcollectionbiodiversity, booksubjectalgae
