. Fossil plants : for students of botany and geology . Paleobotany. 176 LYCOPODIALES [CH. megaspores occur in the lower sporangia, The megaspores, having a mean diameter of 0'8 mm. "quite 40 times the size of the microspores^" are characterised by tubular capitate appendages, and by a conspicuous three-lobed projection (fig. 191, E)^ which, as Scott suggests, may represent the outer spore-wall which has split as the result of germination. It is not im- probable, as shown in fig. 191, I, that this cap was present. Fio. 186. A, B. Lepidodendron Veltheimianum. (Botany School, Cambridge.
. Fossil plants : for students of botany and geology . Paleobotany. 176 LYCOPODIALES [CH. megaspores occur in the lower sporangia, The megaspores, having a mean diameter of 0'8 mm. "quite 40 times the size of the microspores^" are characterised by tubular capitate appendages, and by a conspicuous three-lobed projection (fig. 191, E)^ which, as Scott suggests, may represent the outer spore-wall which has split as the result of germination. It is not im- probable, as shown in fig. 191, I, that this cap was present. Fio. 186. A, B. Lepidodendron Veltheimianum. (Botany School, Cambridge.) C. Lepidodendron macrophyllum. (British Museum. No. 377.) X, Primary xylem ; x-, secondary xylem ; s, Stigmarian rootlet. before germination. The megaspores represented in fig. 191,1, illustrate their characteristic form as seen in a section of a megasporangium, Sm ; the open beak-like portion of the larger spore is probably the apical region which has split along the three-rayed lines. These lines form a characteristic feature of 1 Scott (00) p. 173. 2 Scott [(08) p. 187] suggests that the projection may have formed a passage for the admission of the microspores, or of the spermatozoids which they 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 Seward, A. C. (Albert Charles), 1863-1941. Cambridge : University Press
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