Nature and development of plants . reaking apart of the cells between the dark lines. C,stoma from epidermis of spike. D, the grape fern, Botrychium. The leafis much divided and also forms a branched spore-bearing organ. E, twosporangia, showing the manner of opening for discharge of spores. ring of xylem, cambium and phloem, medullary rays, cortex,cork, etc. (Fig. 216). The spores are borne in peculiar modified outgrowths of theleaves that assume a cylindrical shape in Ophioglossum and be-come more or less branched in the species of the Botrychium(Fig. 215). The structure of these organs pres
Nature and development of plants . reaking apart of the cells between the dark lines. C,stoma from epidermis of spike. D, the grape fern, Botrychium. The leafis much divided and also forms a branched spore-bearing organ. E, twosporangia, showing the manner of opening for discharge of spores. ring of xylem, cambium and phloem, medullary rays, cortex,cork, etc. (Fig. 216). The spores are borne in peculiar modified outgrowths of theleaves that assume a cylindrical shape in Ophioglossum and be-come more or less branched in the species of the Botrychium(Fig. 215). The structure of these organs presents many fea-tures that recall the sporophyte of Authoceros (Figs. 215, B;199). The outer portion of the cylinder consists of chlorophyll-bearing cells which communicate with stomata in some of the 286 THE OPHIOGLOSSALES forms at least. The spore mother cells are also distributed asin Anthoceros, the essential difference being that they are sepa-rated by a larger number of sterile cells and a larger number of -/^--\^T_~--~ .. Fig. 216. Cross-section of a stem of Botrychium: p. pith; x, xylem;in, medullary ray; c, cambium; ph, phloem; c, endodermis; cr, cortex.—After Jeffrey. spore mother cells are also grouped together, forming rather con-spicuous sacs or sporangia (Fig. 215, sp). The spores are formedfrom the mother cells as in the Rryophyta and are discharged
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