. Carnegie Institution of Washington publication. Young sporophyte oi Marattia douglasii still attached to thr gametophyte, pr; Natural si/r. Fig. 12^. A. Young sporophyte of Kaulfussia attached to gametophyte, pr. X2. B. Cotyledon from another plant. X2. C A later leaf; si, stipule. Xl. in the second leaf. Figure 124, C, shows drawings of a number of the forms from my collection, showing the variation from a strictly pinnate to a perfectly dichoto- mous venation. Many of them show an intermediate venation, but with very few exceptions, even where a midrib was present, this was forked at the a
. Carnegie Institution of Washington publication. Young sporophyte oi Marattia douglasii still attached to thr gametophyte, pr; Natural si/r. Fig. 12^. A. Young sporophyte of Kaulfussia attached to gametophyte, pr. X2. B. Cotyledon from another plant. X2. C A later leaf; si, stipule. Xl. in the second leaf. Figure 124, C, shows drawings of a number of the forms from my collection, showing the variation from a strictly pinnate to a perfectly dichoto- mous venation. Many of them show an intermediate venation, but with very few exceptions, even where a midrib was present, this was forked at the apex, indicating. F10. 124. A. Young sporophyte of Angiopttris, with three leaves, i, the cotyledon. Xz. B. Young cotvlcdon. X20. C. Three cotyledons, showing the variation in form. X3. that there had been an early dichotomy. This primary dichotomy of the apex was well shown in a section through a very young leaf (fig. 112, B) where there was no question that such a dichotomy was taking place. In Dancea there is much the same variation in the form of the cotyledon as in Angiopteris. Brebner's figures of D. simplicifolia show that the cotyledon in this species has a midrib with two lateral veins near the base, but sometimes the midrib forks at the summit, indicating again the early dichotomy of the cotyledon. In one. 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 Carnegie Institution of Washington. Washington, Carnegie Institution of Washington
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