. Fossil plants : for students of botany and geology . Paleobotany. 492 CTCADOPHYTA [CH. zone is the secondary xylem the inner edge of which forms bays, and this is composed of alternating zones of vertical and horizontal tracheids (fig. 580, y-^—x^; fig. 581) with bordered, scalariform, pits on their walls traversed by medullary rays generally biseriate and from 4 to 30 cells deep. The disposition of the tracheids is such as to render transverse and radial longitudinal sections. Fig. .580. Golymbetes Edwardsi. Transverse section showing ten alternating zones of wood outside the perimedullary
. Fossil plants : for students of botany and geology . Paleobotany. 492 CTCADOPHYTA [CH. zone is the secondary xylem the inner edge of which forms bays, and this is composed of alternating zones of vertical and horizontal tracheids (fig. 580, y-^—x^; fig. 581) with bordered, scalariform, pits on their walls traversed by medullary rays generally biseriate and from 4 to 30 cells deep. The disposition of the tracheids is such as to render transverse and radial longitudinal sections. Fig. .580. Golymbetes Edwardsi. Transverse section showing ten alternating zones of wood outside the perimedullary zone, pm; y^, y^, etc., vertically running xylem series; x^,x^, etc., horizontally running xylem series; p, pith; It, leaf-traces. (After Stopes; x 2.) practically identical in appearance; the first zone of secondary xylem with its bayed inner edge consists of vertically running elements; this is succeeded by a zone in which the tracheids pursue a horizontal course, and beyond this second zone is another band of vertical elements (fig. 581). 'Where the one zone passes. 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
Size: 1402px × 1782px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, bookpublishercambr, bookyear1898
