Sarcolytes and lipid droplets streaming out of coelomoducts have been directly observed in Eupomathus dianthus (Verrill) after emission of germ cells. Direct observation by polarized light microscopy in sea water has shown that sarcolytes, released through coelomoducts, spontaneously lose their birefrangence when changing their shape. Electron microscopic observation of sections of sarcolytes provides the explanation for the loss of birefrangence; in fact myofilaments of 200-300 Å in diameter organized initially in sarcolytes as regular parallel rows, later become completely loosened and randomly coiled. Observations confirm the view that sarcolysis is an intrinsic process of cell lysis following and somehow related to maturation of gonads and to lipid storage in the coelomic cavity. The massive expulsion of sarcolytes through the coelomoducts seems to be the natural and predominant process of release of sarcolytic byproducts. This is consistent with the rarity of intracoelomic phagocytosis, previously observed by some authors and disputed by others. The Author suggests a physiological interpretation of sarcolysis: the maturation of gonads and related intracoelomic cellular proliferations could be responsible for an increasingly insufficient oxygen supply to the muscles. Eventually, at the time of the expulsion of gonads, an abrupt hydrodynamic change within the coelom (i.e. decrease of hydrostatic pressure) might cause an acute anoxia and an irreversible cellular damage to the muscles.