. Studies in fossil botany . Paleobotany. STAUROPTERIS 337 recalling that of the Zygopteris petioles. The branches are of many orders ; those of intermediate dimensions have a three-armed xylem, while the excessively fine terminal ramifications are traversed by a bundle of correspondingly simple structure. Certain slender strands which are given off concurrently with the. Fig. 126.—Stauropteris oldhamia. Transverse section of vascular bundle of main rachis, showing the cruciform xylem with protoxylem near the four angles. Groups of large sieve-tubes are seen in the bays of the wood, and small-
. Studies in fossil botany . Paleobotany. STAUROPTERIS 337 recalling that of the Zygopteris petioles. The branches are of many orders ; those of intermediate dimensions have a three-armed xylem, while the excessively fine terminal ramifications are traversed by a bundle of correspondingly simple structure. Certain slender strands which are given off concurrently with the. Fig. 126.—Stauropteris oldhamia. Transverse section of vascular bundle of main rachis, showing the cruciform xylem with protoxylem near the four angles. Groups of large sieve-tubes are seen in the bays of the wood, and small-celled phloem between wood and cortex. X 60. S. Coll. 2202. From Tansley, New Pliytologist. main branches are described by M. P. Bertrand as supplying aphlebiae—another point of analogy with Zygopteris. It was on the delicate ultimate branches of the rachis that the terminal sporangia were borne (Fig. 127). The fronds at present known appear to be all fertile ; whether other vegetative leaves also occurred, or the foliage was of an extreme xerophytic type, with the. 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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