. Studies in fossil botany . Paleobotany. 230 STUDIES IN FOSSIL BOTANY The most remarkable point, however, which they observed is, that in traversing the phelloderm the leaf- trace divides into two ; in the leaf-base the two xylem- strands are wide apart. In 1879 Renault described, under the name of Sigillariopsis Decaisnei} a small stem, with leaves attached, from the Permian of Autun; the stem resembles that of Sigillaria Menardi in structure, but the wood contains pitted as well as scalariform. Fig. 95.—Sigillariopsis sulcata. Transverse section of leaf. , the xylem-groups of the doubl
. Studies in fossil botany . Paleobotany. 230 STUDIES IN FOSSIL BOTANY The most remarkable point, however, which they observed is, that in traversing the phelloderm the leaf- trace divides into two ; in the leaf-base the two xylem- strands are wide apart. In 1879 Renault described, under the name of Sigillariopsis Decaisnei} a small stem, with leaves attached, from the Permian of Autun; the stem resembles that of Sigillaria Menardi in structure, but the wood contains pitted as well as scalariform. Fig. 95.—Sigillariopsis sulcata. Transverse section of leaf. , the xylem-groups of the double vascular bundle ; /, lacuna, representing secretory tissue ; t, t, transfusion- tissue, forming a horse-shoe, surrounding the double bundle, but open above ; , palisade tissue on the upper side and flanks of the leaf; f,f, stomatiferous furrows. X 22. S. Coll. 2272. R. S. tracheides ; the leaf is traversed by two parallel vascular bundles, which only fuse towards the tip. These characters are altogether exceptional among Lycopods, but in other respects the structure is quite of the Lycopodiaceous type. Leaves occur in the nodules of the British Coal-measures which agree with those of Renault's plant in possessing two distinct vascular bundles, though presenting some specific 1 Structure comparte de quelques Tiges de la Flore Carbonifere, Paris, 1879, P- 2/°-. 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 Scott, Dukinfield Henry, 1854-1934. London, A. and C. Black
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