in botany, a soft downy substance that grows on the seeds of certain plants, as thistles, hawkweed, &c., serving to scatter and buoy them up in the air.

an eminent philosopher of Alexandria, said by Suidas to have flourished under the emperor Theodosius the Great, who reigned from A.D. 379 to 395. His writings shew him to have been a consummate mathematician: Many of them are lost; the rest continued long in manuscript, detached parts having only been occasionally published in the last century, until Carolus Manoleffius published his remains entire at Bologna in 1660, in folio.