. Studies in fossil botany . Paleobotany. 338 STUDIES IN FOSSIL BOTANY laminae wholly suppressed, cannot yet be determined. The analogy of Zygopteris and Botryopteris, however, speaks strongly for the former hypothesis. The sporangia are nearly spherical sacs, about .7 mm. in diameter, with a wall several cells thick and the outermost layer strongly differentiated. There is no annulus, but a well-marked stomium at the end. Fig. 127.—Stauropteris oldhamia. Three sporangia inserted terminally on ultimate branches of the rachis. In A the stomium, st, is shown. B is cut tangentially. In C, j> i
. Studies in fossil botany . Paleobotany. 338 STUDIES IN FOSSIL BOTANY laminae wholly suppressed, cannot yet be determined. The analogy of Zygopteris and Botryopteris, however, speaks strongly for the former hypothesis. The sporangia are nearly spherical sacs, about .7 mm. in diameter, with a wall several cells thick and the outermost layer strongly differentiated. There is no annulus, but a well-marked stomium at the end. Fig. 127.—Stauropteris oldhamia. Three sporangia inserted terminally on ultimate branches of the rachis. In A the stomium, st, is shown. B is cut tangentially. In C, j> is the palisade-tissue of the rachi. The relatively large spores in C are probably beginning to germinate. Cf. Fig. 128. X about 35. S. Coll.; A, 2213 ; B, 2207 ; C, 2219. R. S. opposite the stalk (Fig. 127, A) served for dehiscence. Numerous spores of the tetrahedral type fill the cavity. At the time when these sporangia were first dis- covered,1 the question was left open whether the plant was a Fern or a Pteridosperm, for there was nothing to show for certain whether the fructification represented 1 Scott, "The Sporangia of Stauropteris oldkamia," New Phytologist, vol. iv. 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 Scott, Dukinfield Henry, 1854-1934. London, A. and C. Black
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