UPTAKE AND INTRACELLULAR DIGESTION OF PROTEIN (PEROXIDASE) IN PLANARIANS

¹ Department of Physiology, University of North Carolina Medical School, Chapel Hill, N. C.

1. Stages in the ingestion of protein, and the formation and ultimate dis-appearance of spherules in the phagocytic cells of Dugesia tigrina were visualized histochemically by the peroxidase technique.

2. The formation of spherules involved the coalescence of numerous small peroxidase-positive granules. Typical spherules were present three hours after feeding kidney from a mouse previously injected with peroxidase, and maximal size of the spherules was achieved by the end of 24 hours.

3. Peroxidase-positive material was confined to the phagocytic cells and disappeared gradually until none remained 8 days following feeding.

4. Pharyngectomized planarians exposed to a medium containing peroxidase in solution absorbed the protein through the epidermis, and formed typical spherules in the phagocytic cells. It is suggested that this may indicate a role of transepidermal absorption of nutrients in regenerating planarians.