This year is the centenary of the surprising discovery in 1896 of zoidogamy in extant cycadophytes and Ginkgo. But by coincidence, also in the same year, the concept of prepollen was introduced. The morphology of prepollen was considered justification for the probable production of motile antherozoids in extinct gymnosperms. In this paper, the history of the prepollen concept is briefly outlined. It is emphasized that, in addition to well-known examples in pteridosperms and cordaitaleans, a prepollen condition also occurred among late Paleozoic conifers.Toward the end of the 19th century, it was generally assumed that seed plants, both extant and extinct, were uniformly characterized by siphonogamy. This fertilization mechanism involves formation of a pollen tube, a tubular outgrowth of the microgametophyte through which immotile gamete cells or nuclei are delivered to the archegonia. The mechanism is fundamentally different from zoidogamy, the fertilization by means of motile antherozoids, which can be observed in spore-bearing plants.As early as 1887, the possibility of zoidogamy in extinct gymnosperms was mentioned by the French palaeobotanist Renault (1), but this view attracted little attention. Then in 1896, a century ago this year, the assumption of uniform siphonogamy in gymnosperms was definitively shown to be a false concept. By remarkable coincidence, the presence of zoidogamy was independently discovered in both recent and in fossil plants in the same year.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.