. The germ-cell cycle in animals . Cells. Fig. 27. —A. Clathrina blanca. Blastula stage showing posterior gran- ular cells (). (From Minchin, 1900.) B. Oogonium of a sponge containing inclusions in the cytoplasm. {From Jorgensen, 1909.) C. Two oogonia in the ectodermi of Hydra fusca, each with a cytoplasmic inclusion. {From Downing, 1909.) species there is only one; in others four or more appear; and sometimes they are entirely absent. This last condition results from the formation of amebocytes before the fixation of the larva. In many other sponges the archeocytes migrate in at the post
. The germ-cell cycle in animals . Cells. Fig. 27. —A. Clathrina blanca. Blastula stage showing posterior gran- ular cells (). (From Minchin, 1900.) B. Oogonium of a sponge containing inclusions in the cytoplasm. {From Jorgensen, 1909.) C. Two oogonia in the ectodermi of Hydra fusca, each with a cytoplasmic inclusion. {From Downing, 1909.) species there is only one; in others four or more appear; and sometimes they are entirely absent. This last condition results from the formation of amebocytes before the fixation of the larva. In many other sponges the archeocytes migrate in at the posterior pole and partially or entirely fill up the segmentation cavity. Comparatively little is known about the embryology of Hexactinellida and. 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 Hegner, Robert William, 1880-1942. New York : The Macmillan Company
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectcells, bookyear1914
