The ultrastructure and metal-containing inclusions of mature cell types in the hepatopancreas of a crayfish.

The ultrastructure of the hepatopancreas of the crayfish Austropotamobius pallipes (Lereboullet) is described in relation to its function in digestion. X-ray microprobe analyses of the cells of this tissue have been obtained after using a variety of fixatives and plasma oxygen etching. The distribution of metals in the digestive cells is considered in relation to the polarization of the cells and their ability to absorb materials across the apical and basal cell membranes.