. Heredity and evolution in plants. Heredity; Plants. LIFE HISTOKY OF A FERN down. The dorsal surface would then be the under surface, and the ventral surface the upper one. Organisms or organs having two such surfaces clearly distinguishable are said to have dorso-ventral diferentiation. Among many- other structures thus differentiated are foliage-leaves, sporophylls, man, fishes, and other animals. In buds the dorsal surface of leaves is the upper or outer surface; when foliage leaves are fully expanded the dorsal surface is commonly underneath, and the ventral surface Fig. —Arch
. Heredity and evolution in plants. Heredity; Plants. LIFE HISTOKY OF A FERN down. The dorsal surface would then be the under surface, and the ventral surface the upper one. Organisms or organs having two such surfaces clearly distinguishable are said to have dorso-ventral diferentiation. Among many- other structures thus differentiated are foliage-leaves, sporophylls, man, fishes, and other animals. In buds the dorsal surface of leaves is the upper or outer surface; when foliage leaves are fully expanded the dorsal surface is commonly underneath, and the ventral surface Fig. —Archegonia of a fern (Adiantum). A, young archegonium; B, mature; C, top view, showing terminal cells of the four rows of wall cells; V, wall of venter; e, egg; , ventral canal-cell; , neck-canal; sp, sperms entering the neck-canal. A and B in longitudinal section. 14. Reproductive Organs: Archegonia.—Examination of the ventral surface of a mature prothaUus with a lens will reveal near the notch and on the cushion, several tiny flask-shaped bodies, the archegonia. Each arche- gonium consists of a wall, one cell thick, and contents (Fig. 2i). The neck projects away from the surface. 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 Gager, C. Stuart (Charles Stuart), 1872-1943. Philadelphia, P. Blakiston's Son & Co.
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectplants, bookyear1920
