In the Tudava cycle told at Laba'i on the northern shore of Kiriwina, all the inhabitants fled the man-eating ogre Dokonikan, abandoning one woman, Bolutukwa or Mitigis, who lived alone in a grotto by the beach. One night, as she slept, water dripping from the stalactites of the cave pierced her and she conceived. Her son was Tudava, the great culture-hero who later killed Dokonikan. Malinowski repeatedly used this fatherless conception as evidence of Trobriand beliefs about procreation, in which pregnancy is caused by spirit children rather than by fathers, and matrilineal descent alone determines kinship.