Histology and Histochemistry of the Capsule of Proteocephalus Sp. (Cestoda) in Lepomis Macrochirus

Histochemical studies performed on livers of the bluegill, Lepomis macrochirus, containing the larval cestode, Proteocephalus sp., indicated that the cellular capsule surrounding the parasite was composed of glycogen, basic protein with large concentrations of protein-bound amino groups, and tyrosine. An amorphous layer between the capsule and parasite gave positive reactions for mucoproteins, basic proteins, tyrosine, and tryptophan. The capsule was derived from reticulo-endothelial cells of the host, and the host plasma was the source of the amorphous layer.