The largest macromolecules of glycogen synthesized histochemically in tissue cells were spherical branching bodies composed of several large branches with many smaller branches, presumably containing a Meyer structure of α-1,4-1,6-glucosidic linkages. The synthesized macromolecules of glycogen were variable in size and structure, and were closely related to the activities of enzymes, Phosphorylase, branching glycosyltransferase, and glycogen synthetase. The glycogen molecules appeared to be individually free in the cytoplasmic matrices. It is possible that they are synthesized there, and not related to the membrane system.