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Abstract

cells in each stage I, II and III existed in the parenchyma. But almost all megakaryocytes in stage IV existed as free cells presumably in a sinusoid. It is assumed that, after formation of the demarcation membrane in the whole cytoplasm, megakaryocyt es in t h e parenchyma move into the sinusoids, and then the whole cytoplasm of megakaryocytes is broken expl osively into small pieces to be designated as platelets.