. Elementary text-book of zoology, tr. and ed. by Adam Sedgwick, with the assistance of F. G. Heathcote. . FIG. -153.—a, Egg tube of Foificitla. , Nutritive cells ; E , ovum; OE, epithelium of the wall of the egg tubo. b, Me liau part of the egg tube of a Moth. l?z, nutritive cells of the yolk-chamber; Ez, ovum in the germ-chamber; H, connective tissue investment, so-called serosa. c, Egg-tube of Aphisplafanoides with three ovarian chambers (Ez—Ez") and the terminal nutritive chamber with its cells Ni. Dx, yolk cord. Diptera (Cccidomyia, Miastor, fig. TOO), which can reproduce them- s
. Elementary text-book of zoology, tr. and ed. by Adam Sedgwick, with the assistance of F. G. Heathcote. . FIG. -153.—a, Egg tube of Foificitla. , Nutritive cells ; E , ovum; OE, epithelium of the wall of the egg tubo. b, Me liau part of the egg tube of a Moth. l?z, nutritive cells of the yolk-chamber; Ez, ovum in the germ-chamber; H, connective tissue investment, so-called serosa. c, Egg-tube of Aphisplafanoides with three ovarian chambers (Ez—Ez") and the terminal nutritive chamber with its cells Ni. Dx, yolk cord. Diptera (Cccidomyia, Miastor, fig. TOO), which can reproduce them- selves while still in the larval stage, may be explained. The development of the embryo takes place as a rule outside tho body of the mother, and occupies a longer or shorter period of time, according to the temperature and the time of the year. The centro- iccithal segmentation leads to the formation of a superficial blastoderm, which surrounds the ovum, and always consists of a single layer of ceils. A part of this blastoderm, on that side ot the ovum which the later history shows to be ventral, becomes thickened and sharply. 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 Claus, Carl, 1835-1899; Sedgwick, Adam, 1854-1913; Sinclair, F. G. (Frederick Granville), b. 1858. London, Swan Sonnenschein & co.
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Keywords: ., book, bookcentury1800, bookcollectionbiodiversity, bookdecade1890
