Published online by Cambridge University Press: 15 September 2014
WHILE studying the fossil Osmundaceœ several interesting points illustrating the origin of the leaf-trace were brought under our notice, which are exhibited with such exceptional clearness in Thamnopteris Schlechtendalii, Eichwald, sp., that they deserve especial recognition. The full discussion of the subject, however, is reserved until the publication of the next part of our memoir on the fossil Osmundaceœ.
The departure of the leaf-trace in Thamnopteris is typically protostelic. That is to say, the xylem of the leaf-trace first of all appears as a protuberance on the surface of the xylem of the stem (fig. 1).
page 433 note * Eichwald, , Lethœa Rossica, vol. i., p. 93, pl. xx., figs. 2 and 5, 1860Google Scholar; Brongniart, , Tableaux des genres des végétaux fossiles, pp. 35–36, 1849.Google Scholar
page 435 note * Tansley, A. G., “Lectures on the Evolution of the Filicinean Vascular System,” New Phytologist, vol. vi., p. 64, 1907.Google Scholar