Shrunken heads, South American, 19th century.

ECUADOR - DECEMBER 18: Head shrinking is a custom practised by several tribes in South America, notably the Jivaro of southern Ecuador. They believe that if an enemy is killed in battle, his head must be shrunk as soon as possible, in order to capture his �avenging soul� and prevent it from exacting retribution against the warrior who killed him. The shrinking process involves removing the skull and filling the cavity with hot sand to dry out the skin. It takes about a week for the head to shrink to the size of an orange. The Jivaro hold ritual feasts culminating in the ceremonial expulsion of the �avenging souls� back to where they originated. After this the head has no power and may be kept as a simple trophy, sold, or just thrown away. (Photo by SSPL/Getty Images)