title: The polar co-ordinate model for pattern regulation in epimorphic fields: a critical appraisal.
mesh_terms: D000663:Amphibians; D000818:Animals; D003058:Cockroaches; D004330:Drosophila; D005121:Extremities / Q000502:physiology; D007313:Insecta; D008954:Models, Biological; D009024:Morphogenesis; D012038:Regeneration; D014921:Wings, Animal / Q000502:physiology; D014945:Wound Healing