. The Eusporangiatae; the comparative morphology of the Ophioglossaceae and Marattiaceae. Ophioglossaceae; Marattiaceae. Fig. 172. A, B. Two longitudinal sections of a young sporophyte of Marattia douglasii. /^, second leaf; »-^, second root. X140. C. Part of primary root, showing cells in- fected by endophytic fungus. Fig. 173. Section of a young sporophyte of Marattia douglasii. si, stem apex; /, young leaves; /â , roots. X 25. and scales like those we have seen in the other genera. They are more like those of Kaulfussia than like the peltate scales found in Dancea. Sections of a somewhat o
. The Eusporangiatae; the comparative morphology of the Ophioglossaceae and Marattiaceae. Ophioglossaceae; Marattiaceae. Fig. 172. A, B. Two longitudinal sections of a young sporophyte of Marattia douglasii. /^, second leaf; »-^, second root. X140. C. Part of primary root, showing cells in- fected by endophytic fungus. Fig. 173. Section of a young sporophyte of Marattia douglasii. si, stem apex; /, young leaves; /â , roots. X 25. and scales like those we have seen in the other genera. They are more like those of Kaulfussia than like the peltate scales found in Dancea. Sections of a somewhat older sporophyte are shown in figure 172, this section being made at right angles to the one just described. The cotyledon in this specimen was fully expanded and the primary root had penetrated into the earth. The arrangement of the bundles was the same as in the younger sporophyte described, except that the third leaf was now visible and the second root was already well advanced. The section passed exactly through this root, the stele of which is seen to join that of the second leaf and is practically continuous with it. The young trace from the third leaf joins the second leaf trace near its junction with the second root. The apical cell of the latter was readily seen and appears in longitudinal section of nearly triangular form, but with the base somewhat truncate (fig. 177, C). The tracheary tissue in the middle of the sporophyte is pretty well advanced and the formation of the tracheary tissue has extended for some distance into the primary root and the cotyledon. In the former a single elongated tannin sac could. 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 Campbell, Douglas Houghton, 1859-1953. Washington, D. C. , Carnegie Institution of Washington
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