. Fossil plants : for students of botany and geology . Paleobotany. 18 GINKGOALES [CH. veins spread from the base of the lamina, the veins in the middle of the leaf being generally about 0-8—1 mm. apart. The stomata are practically confined to the lower surface of the lamina. The epidermal cells are polygonal and the walls slightly sinuous as in the recent species, and over the veins the cells are longer and narrower (fig. 636, A). Many of the larger epidermal cells have a cuticular ridge in the middle of the outer wall, represented in the figure by a black line. The stomata agree closely with
. Fossil plants : for students of botany and geology . Paleobotany. 18 GINKGOALES [CH. veins spread from the base of the lamina, the veins in the middle of the leaf being generally about 0-8—1 mm. apart. The stomata are practically confined to the lower surface of the lamina. The epidermal cells are polygonal and the walls slightly sinuous as in the recent species, and over the veins the cells are longer and narrower (fig. 636, A). Many of the larger epidermal cells have a cuticular ridge in the middle of the outer wall, represented in the figure by a black line. The stomata agree closely with those of Ginkgo biloba; the two guard-cells are sur- rounded by a group of subsidiary cells characterised by their. Fig. 636. Ginkgoites digilata; epidermal cells (A) and stoma (B). C. Stoma of Ginkgo biloba in two planes. (A, B, drawn by Miss N. Bancroft.) papillose heavil)' cuticularised walls overarching the stoma (fig. 636, B). The features shown in fig. 636 are not brought out in drawings from cuticles of the same specimen reproduced by Dr Stopes^ in her account of fossil plants from Brora: this may be due in part to a difference in the level at which the stomata were drawn. The stoma of Ginkgo biloba represented in fig. 636, C illustrates the considerable difference produced by viewing a stoma in shghtly different planes^. No seeds have been found attached to stems bearing leaves of G. digitata, but seeds closely resembUng those of the recent species 1 Stopes (07) p. 380. - Seward (11) p. 47, PI. v. fig. 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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Keywords: ., bookcentury1800, bookdecade1890, bookpublishercambr, bookyear1898
