A contractile ring and cortical changes found in the dividing Tetrahymena pyriformis.
D000818:Animals; D002455:Cell Division; D003593:Cytoplasm / Q000648:ultrastructure; D003599:Cytoskeleton / Q000648:ultrastructure*; D008854:Microscopy, Electron; D013769:Tetrahymena pyriformis / Q000502:physiology / Q000648:ultrastructure*