PRINGSHEIM, NATHANAEL (1823-94). .A German botanist, born at \Vziesko. near Landsberg, Silesia. For a time he studied medicine, associated himself with the Liberal political movement, and then turned definitely to natural science, in which cryptogamic botany soon became his specialty. After studying at the universities of Breslau, Leipzig, Berlin, and Paris, he submitted, at Berlin, an essay Zur Ent wielaungsgeschichte der Achlya prolifera and be came a lecturer there. As a result of his essays GrundliniCn ciner Thcorie dcr Pflanzenzelle (1S54) and Ucber die Befruehtung and Keim ung der Algen end des Wesen des Zcugungsaktcs (1855-57), he was chosen in 1858 a member of the Royal Academy of Scientists. In 1857 he founded the Jahrbuch fiir wisscnsclwft fiche Botunik, which he edited up to the time of his death. He was professor of botany at Jena from 1S64 to 1SOS and then returned to his lecture ship at Berlin, but he had little interest in teach ing and devoted himself almost entirely to re search. In 1S82 he founded and became the first president of the German Botanical Society.
Pringsheim, Thurct, and Hornet are regarded as the founders of the scientific study of the alga., and the German was one of the first investigators to prove the existence of a sexual process in this kind of vegetation. During the last twenty years of his life his attention was directed more to plant physiology than to the morphological ques tions in which he won his greatest successes. He made extensive researches in the effect of light on plants, and developed a new, though not wholly satisfactory, theory of the function of chloro phyll. He was one of the foremost cryptogamic botanists of the nineteenth century. Among his works, which were published in four volumes at Jena in 1893-96, are the following: Bcitriige zur Morphologic der Meercsalgcn (1862) ; Ueber die Embryobikd4Hng der tlefiisskryptogamen end dos von Salrinia natuns (1863) ; Veber Paarung von Schwiirmsporen (1869) ; Weitert Xachtriige zur Morphologic and Systcmatik der Saprolegniacecu (1873) ; Untersuehungen fiber dos Chlorophyll (1874).