It is often vacuolar, sometimes granular, and in other cases it is a homogeneous body with no visible structure or differentiation.
In Polia the connective tissue enclosed in the external muscular layer is eminently vacuolar - all the intermediate stages between such cells in which the vacuole predominates and the nucleus is peripheral and those in which the granular protoplasm still entirely fills them being moreover present.
Although an integral portion of the gut, it has ceased to assist in alimentation, its epithelium undergoes vacuolar differentiation and hypertrophy, and its lumen becomes more or less vestigial.