title: Evidence for a pollination-drop mechanism in paleozoic pteridosperms.
abstract: A noncellular substance containing pollen and spores has been discovered protruding from the micropyle of a seed fern ovule of Middle Pennsylvanian age. This provides direct evidence that pollination-drop mechanisms comparable to those of many extant gymnosperms characterize some Paleozoic pteridosperms.
authors.forename: G W
authors.initials: GW
authors.lastname: Rothwell