The New Student's Reference Work/Siphonogamy

Siphonogamy (sī-fō-nŏg′ȧ-mĭ), a condition in plants in which pollen-tubes are developed for the transfer of the male cells to the eggs. The seed-plants are siphonogamous; while in the lower plants the male cells usually swim to the eggs. As a consequence, the Spermatophytes are called Siphonogams by some botanists.