. The algae. Algae. Fig. 113 Fucus. Aj transverse section 'female' conceptacle of F. spiralis var. platycarpus. B, transverse section 'male' conceptacle of F. vesiculosus. C, portion of thallus of F. spiralis to show structure ( X 125). D, origin of hyphae i cm. below apex, F. spiralis ( x 235). E, antheridia (microsporangia). F, young, and G, old oogonium (megasporangium).H, liberated ova. e =endochiton,m =mesochiton. I, ova being liberated, e =^ endochiton, w =mesochiton. J, empty sporangium showing torn exochiton. K, ovum being fertilized. L, antherozoid. (C, D, after Pennington; rest after
. The algae. Algae. Fig. 113 Fucus. Aj transverse section 'female' conceptacle of F. spiralis var. platycarpus. B, transverse section 'male' conceptacle of F. vesiculosus. C, portion of thallus of F. spiralis to show structure ( X 125). D, origin of hyphae i cm. below apex, F. spiralis ( x 235). E, antheridia (microsporangia). F, young, and G, old oogonium (megasporangium).H, liberated ova. e =endochiton,m =mesochiton. I, ova being liberated, e =^ endochiton, w =mesochiton. J, empty sporangium showing torn exochiton. K, ovum being fertilized. L, antherozoid. (C, D, after Pennington; rest after Oltmanns.) where they come from adjacent tissue. This method of for- mation occurs in Sargassum, Bifurcaria, etc. The tongue cell and apical cell of the Hnear series are regarded as vestigial hairs so that the conceptacles really originate from the basal cell of a hair. The cryptostomata or hair pits are regarded as a juvenile stage of the fertile conceptacle, because sporangia are frequently associated with the hairs, or else hairs occur in the same cavity after the sporangia have been lost. It has also been suggested in the past that the cryptostomata may represent abortive sexual conceptacles which fail to develop, or alternatively that they are structures which have 201. 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
