Abstract: AIM : To study the formation and metabolism of calcareous corpuscles from Cysticercus cellulosae at the ultrastructure level. METHODS: Transmission electron microscopy. RESULTS: The developmental processes of calcareous corpuscles could be divided into two stages: the intracellular formation stage and the extracellular metabolic stage. The calcareous corpuscles were formed in a cell which we named calcareous corpuscle forming cell. At the early stage of the formation, the corpuscles appeared to be secretory granules in the cells. With the development of the co rpuscles, they became bead-shaped and lamellae-like, then the calcareous corpuscle forming cell enlarged and the organellae degenerated. Finally the corpuscles gathered to form particle substances with black dense background,while the nucleus and organellae of the forming cell all disappeared . There were 1- 3 or 10- 20 calcareous corpuscles in a mature forming cell. Then, the corpuscles were released to the parenchymal tissues and gradually appeared to be concentric lamella or an empty cavity during the metabolic process . CONCLUSION : The calcareous corpuscles were formed in calcareous corpuscle forming cell and consumed in metabolic process in the parenchymal layer of Cysticercus cellulosae.

Key words: Cysticercus cellulosae, calcareous corpuscles, formation, metabolism, ultrastructure