Abstract
Hepatic intranuclear glycogen of the larva of Rana pipiens has been studied by the periodic acid Schiff reaction (controlled by diastase digestion), by electron microscopy, and by interference and phase microscopy. The glycogen occurs sporadically as one or two masses in the central part of the nucleus. The absence of nuclear envelope and of typical non-glycogen cytoplasmic elements shows that the nuclear glycogen inclusions are not cytoplasmic areas that have been enclosed within the nucleus. The central position, difference in rate of resorption, and other evidence indicates that the nuclear glycogen has been synthesized in situ. Comparison with the nucleolus suggests that the nuclear glycogen body is formed as a result of activity at a specific chromosomal site.