[Vesicles of the smooth endoplasmic reticulum in the Y organ of Carcinus maenas L. (Crustacea, Decapoda)].

The smooth endoplasmic reticulum in the Y organ cells consists of vesicular and tubular elements containing a slightly electron dense substance. The contents of these vesicles are released either at the gland surface or within the intercellular spaces. These processes which are concomitant with the hormonal activity preparatory to the molting, may represent the release of crustecdysone or of one of its precursors.