title: The pigmentary system of planaria. I. Morphology.
abstract: The pigmentary system of the planaria, Dugesia gonocephala s.l. (Platyhelminthes, Turbellaria, Tricladida), has been studied by light and electron microscopy. The system consists of granules contained in chromatophore-like cells embedded in the parenchyma. The cell processes penetrate between the muscle layers and extend to the sub-epidermal basal lamina. The nature of the pigment and the comparative anatomical significance of the chromatophore structure is discussed.
mesh_terms: D000818:Animals; D002856:Chromatophores / Q000648:ultrastructure*; D008854:Microscopy, Electron; D010858:Pigmentation; D010932:Planarians / Q000648:ultrastructure*; D014419:Turbellaria / Q000648:ultrastructure*