median diverticulum from caudal part of the roof of diencephalon; proliferation of cells in its walls converts it into the pineal body, a conic gland.
pin·e·al bud
(pin'ē-ăl bŭd) A median evagination of the caudal part of the diencephalon; proliferation of the cells in its walls converts it into the pineal gland (body). Synonym(s): pineal diverticulum.