. Carnegie Institution of Washington publication. 18 THE OPHIOGLOSS All S I he antheridia form a more or less evident row, even in the very young prothallium, and later this median row of antheridia is raised upon an elevated ridge, upon whose sides the- archegonia later make their appearance (fig. 6, /)). The gametophyte of closely resembles the early stages of B. virgin- ianum. It is very much smaller and rarely exceeds a length of i millimeters, and, like the young stages in B. virgimanum, it is covered with mam long rhizoids (tig. 8, .•/, B.) The smaller prothalha are globular or
. Carnegie Institution of Washington publication. 18 THE OPHIOGLOSS All S I he antheridia form a more or less evident row, even in the very young prothallium, and later this median row of antheridia is raised upon an elevated ridge, upon whose sides the- archegonia later make their appearance (fig. 6, /)). The gametophyte of closely resembles the early stages of B. virgin- ianum. It is very much smaller and rarely exceeds a length of i millimeters, and, like the young stages in B. virgimanum, it is covered with mam long rhizoids (tig. 8, .•/, B.) The smaller prothalha are globular or oval in shape; the larger ones somewhat heart-shaped. I [ofmeister states that the antheridia occur upon the upper surface and the archegonia below; but Bruchmann found that both archegonia and antheridia were confined to the upper surface, as in B. virginianum. As in the latter, also, the dorsal ridge is present, bearing the antheridia upon its crest and the archegonia upon its flanks. I he large prothallia of B. virginianum live for mam years, and Jeffrey even found a plant bearing spores, which was still connected with a prothallium. It is probable that the very much smaller prothallia of B. lunaria have a shorter duration, but in this species also the prothallium persists for some time after the young sporophyte is established. THE HISTOLOGY OF THE GAMETOPHYTE OF BOTRYCHI1 M- In B. virginianum the forward part of the prothallium is made up of colorless tissue, which extends for some distance beyond tin youngest antheridia. The apical meristem in this species (fig. 6, E) lies on the Upper side of the prothallium; in a vertical longitudinal section it shows a group of columnar cells, one of which is. Fi<;. 9. A. Transverse section of a gametophyte of G phioglossum pendulum, showing position of endophytic fungus. X20. The shaded region is occupied by the endophyte. B. Endophyte from prothallium of Botrychtum virginianum* C. Sporangium-like enlargements of endophyte. prob
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Keywords: ., bookauthorcarnegie, bookcentury1900, bookdecade1910, bookyear1911
