Formation of Embryo Thromboblasts in Chick Blastoderm: Morphology, Site of Production and Time of Emergence in the Blood: (embryo thromboblast/glycogen deposit/differentiation/chick blastoderm).

Thrombocytes in the blood of chick embryos (termed embryo thrombocytes by Lucas and Jamroz) have PAS-positive granules in their cytoplasm. Electron microscopic observations reveal that the embryo thrombocytes contain glycogen granules present singly or in clumps. The presence of these inclusions and other morphological characteristics were used as specific markers to distinguish embryo thrombocytes from primitive erythroid cells.