. Fossil plants : for students of botany and geology . Paleobotany. 220 LYCOPODIALES [CH. dendron, and it is noteworthy that traces of partially- disorganised tissue, described as large canals, in the region external to the secondary wood, bear a resemblance' to the secretory tissue of Lepidodendron. Other interesting features are presented by the structure of the outer cortex and the parichnos. The outer cortex in the leaf-scar region is composed of parenchyma, but for the most part it consists of radially elongated groups of thin-walled. Fig. 202. A. Sigillaria elegam Brongn. (Section in Dr
. Fossil plants : for students of botany and geology . Paleobotany. 220 LYCOPODIALES [CH. dendron, and it is noteworthy that traces of partially- disorganised tissue, described as large canals, in the region external to the secondary wood, bear a resemblance' to the secretory tissue of Lepidodendron. Other interesting features are presented by the structure of the outer cortex and the parichnos. The outer cortex in the leaf-scar region is composed of parenchyma, but for the most part it consists of radially elongated groups of thin-walled. Fig. 202. A. Sigillaria elegam Brongn. (Section in Dr Kidston's Collection cut from the specimen shown in fig. 193, D.) B, C. Sigillaria elongata Brongn. It, leaf-trace. (From specimens in the collection of Prof. Bertrand.) parenchyma enclosed in a framework of thicker-walled and elongated elements (fig. 200, B, c^). This type of cortex, to which Brongniart applied the name Dictyoxylon, would produce a cast in the case of a partially decorticated stem characterised by a surface formed of irregularly oval and raised areas bounded by narrow grooves ; the greater prominence of the former being due to the more rapid decay of the softer tissue, which would 1 Eenault and Grand'Eury (75) PI. i. fig. 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 Seward, A. C. (Albert Charles), 1863-1941. Cambridge : University Press
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Keywords: ., bookcentury1800, bookdecade1890, bookpublishercambr, bookyear1898
