 A number of other animals, including chickens, snakes, and turtles, have also been known to survive for some time after being decapitated, as they have a slower metabolism, and their nervous systems can continue to function at some capacity for a limited time even after connection to the brain is lost, responding to any nearby stimulus.Although head transplantation by the reattachment of blood vessels has been successful with animals, a fully functional reattachment of a severed human head (including repair of the spinal cord, muscles, and other critically important tissues) has not yet been achieved.Early versions of the guillotine included the Halifax Gibbet, which was used in Halifax, England, from 1286 until the 17th century, and the "Maiden", employed in Edinburgh from the 16th through the 18th centuries.