特殊用法brain rudiment1.脑原基mesenteron rudiment1.中肠原基optic rudiment1.视原基perihaemal rudiment1.围血系原基(棘皮动物)posterior mesenteron rudiment1.后中肠原基scale rudiment1.鳞痕thoracico-abdominal rudiment1.胸腹原基wing rudiment1.翅迹