Article révisé par les pairs
Résumé : The microscopic structure of the pyloric caeca of the starfish Asterias rubens is described. The wall of the pyloric caeca is made up of three layers: a coelomic and a digestive epithelium separated from each other by a connective tissue layer with muscle and nerve fibres adjacent the epithelia. The digestive epithelium is composed of various types of cell: storage cells, special-current producers, mucocytes, zymogen cells and coelomocyt-like cells. The possible role that coelomocyt-like cells and cells protruding into the lumen play with regard to the changes in size of the pyloric caeca during the reproductive cycle is discussed. The amount of lipid droplets in the storage cells and the activity of the granular endoplasmic reticulum of these cells vary during the annual reproductive cycle and both reach a maximum during the intensive growth of the gonads. © 1983 BRILL.