. Fossil plants : for students of botany and geology . Paleobotany. 1 i 1 5£; S f ~ 1 |U3 Fig. 72. A. External xylem elements and eamblum, c, "with imperfect phloem. X100. B. Carinal canal containing protoxylem, px. x 65. C. Eadial longitudinal section through nodal xylem, px. x 35. D. Phloem elements; s, sieve-tubes; p, p, parenchymatous cells. {A—C. After Williamson and Scott. -D. After Eenault.) the same is true of Calamites. In fig. 72, C, we have part of a radial section of a Calamite twig in which the broad mass of short nodal tracheids is clearly shown; this nodal wood forms a prom
. Fossil plants : for students of botany and geology . Paleobotany. 1 i 1 5£; S f ~ 1 |U3 Fig. 72. A. External xylem elements and eamblum, c, "with imperfect phloem. X100. B. Carinal canal containing protoxylem, px. x 65. C. Eadial longitudinal section through nodal xylem, px. x 35. D. Phloem elements; s, sieve-tubes; p, p, parenchymatous cells. {A—C. After Williamson and Scott. -D. After Eenault.) the same is true of Calamites. In fig. 72, C, we have part of a radial section of a Calamite twig in which the broad mass of short nodal tracheids is clearly shown; this nodal wood forms a prominent projection towards the pith. In the lower part of the section the remains of some spiral protoxylem tracheids are seen in a carinal canal. The tracheids of the nodal wood are often reticularly pitted, and so differ in appearance from the ordinary scalariform elements. It is rare to find the phloem clearly preserved, but in specimens where it has been possible to examine this portion of the vascular bundles, it is found to consist of elongated. 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
