. Fossil plants : for students of botany and geology . Paleobotany. Fig. 149. Lepidodendron vasculare, a, immature tracheae; vi, meristem; mr, medullary ray; x, xylem. A. Longitudinal section through the edge of the secondary wood. B. Short tracheae in the centre of the stele. (From a specimen from the Halifax Hard bed in Dr Kidstou's Collection.) diameter of the tracheae gradually increases and parenchymatous cells become associated with the elongated scalariform elements. In the central region the stele is composed of parenchymatous tissue arranged in vertical series of short cells, interspe
. Fossil plants : for students of botany and geology . Paleobotany. Fig. 149. Lepidodendron vasculare, a, immature tracheae; vi, meristem; mr, medullary ray; x, xylem. A. Longitudinal section through the edge of the secondary wood. B. Short tracheae in the centre of the stele. (From a specimen from the Halifax Hard bed in Dr Kidstou's Collection.) diameter of the tracheae gradually increases and parenchymatous cells become associated with the elongated scalariform elements. In the central region the stele is composed of parenchymatous tissue arranged in vertical series of short cells, interspersed with short tracheae distinguished by the greater thicknessof theirwalls and by their scalariform and reticulate thickening bands. Some of these short tracheae are shown in vertical section in fig. 149, B: the fine and broken lines connecting adjacent thickening bands probably represent the remains of the original wall. These delicate bands, which have been figured in various species. 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
