Nathanael Pringsheim, a German botanist, of Jewish parentage, born near Landsberg, Silesia, Nov. 30, 1823. He studied in several German universities and in Paris, went to Berlin in 1851, and in 1857 commenced the publication of the Jahrbucher fur wissenschaftliche BotaniTc, which he still edits (1875). He was professor of botany at Jena from 1864 to 1868. He has chiefly distinguished himself by his minute researches into the anatomy and physiology of cryptogamous plants, demonstrating the presence of antheridia or male organs in various algae, and establishing the fact of a true bisexual reproduction in several genera. Accounts of some of these discoveries are contained in his work Ueber die Befruchtung und Keimung der Algen und das Wesen des Zeu-gungsactes (I855). Among his other works are: Grundlinien einer Theorie der Pflanzen-zelle (Berlin, 1854); Beitrdge zur Morphologie der Ifeeresalgen (1862); and Ueber den Gang der morphologischen Differ'enzirung in der Sphacelarien-Reihe (1873).