. The origin of a land flora, a theory based upon the facts of alternation. Plant morphology. 544 FILICALES by curling over of the margin of the pinnule, as in Mohria and Sckizaea, and in some degree in Aneimia : or there may be a special protective growth, comparable to the indusium of the Hymenophyllaceae, which completely covers each separate sporangium, as in Lygodium (Fig. 301).. Disposition uf the sporangia of the Schizaeaceae. A = .SV//. dickotojna, J. Sm., part of a fertile segment (sorophore). B, C' = Lygodium jafionicum^ Sw. />' = zpex of a young fertile segment. C' = mature ferti
. The origin of a land flora, a theory based upon the facts of alternation. Plant morphology. 544 FILICALES by curling over of the margin of the pinnule, as in Mohria and Sckizaea, and in some degree in Aneimia : or there may be a special protective growth, comparable to the indusium of the Hymenophyllaceae, which completely covers each separate sporangium, as in Lygodium (Fig. 301).. Disposition uf the sporangia of the Schizaeaceae. A = .SV//. dickotojna, J. Sm., part of a fertile segment (sorophore). B, C' = Lygodium jafionicum^ Sw. />' = zpex of a young fertile segment. C' = mature fertile segment, at („t) the sheaths have been removed, so as to display the sporangia. D = Mohria cajfrornm (L.) segment of a fertile pinna, /i, F= Aneimia Phyllitidis, Sw. /t=side view of a young fertile segment. A = fertile segment from below (A, B, K after Prantl. C, />, F after Diels, from Engler and Prantl, .Vat. ). Spore-Producing Members. These in the Schizaeaceae are simply the solitary sporangia, each of which Prantl recognised as constituting a " monangial ; He accurately worked out their development, and found them to arise in acropetal order on each fertile segment: he ascribes to them all an origin from cells of the marginal series, with a terminal position on the fertile vein. Con- sequently the protecting flanges must, according to his account, be accessory growths from the adaxial surface of the leaf. As Diels remarks, however, extended and renewed investigations are desirable before this is finally It seems improbable for Sckizaea, and still more so for certain ot the related fossils: from their mature position in these it would appear 1 Nat. Pflaiizenfam., i., iv., p. 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 Bower, F. O. (Frederi
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