title: Evidence of pollen tubes in paleozoic pteridosperms.
abstract: A saccate pollen grain with a branched pollen tube has been discovered within the pollen chamber of a fossil seed-fern ovule of Middle Pennsylvanian age. This suggests that microgametophytes comparable to those of living gymnosperms were produced by some Paleozoic pteridosperms.
authors.forename: G W
authors.initials: GW
authors.lastname: Rothwell