Strasburger, Eduard Adolf

▪ German cytologist

born Feb. 1, 1844, Warsaw, Pol., Russian Empire [now in Poland]

died May 18, 1912, Bonn, Ger.

      German plant cytologist who elucidated the process of nuclear division in the plant kingdom.

      Strasburger was educated at the universities of Paris, Bonn, and Jena, where he received a Ph.D. in 1866. He taught at the universities of Warsaw (1868), Jena (1869–80), and Bonn (1880–1912). Strasburger's earliest research was a continuation of the work begun by the German botanist Wilhelm Hofmeister on the alternation of generations. Strasburger was the first to provide an accurate description of the embryonic sac in gymnosperms (such as conifers) and angiosperms (the flowering plants) along with a demonstration of double fertilization in the angiosperms. He set forth the basic principles of mitosis in his Über Zellbildung und Zelltheilung (1876; “On Cell Formation and Cell Division”), and in each succeeding edition he clarified and modified the description of the process until in the third edition (1880) he enunciated one of the modern laws of plant cytology: that new nuclei can arise only from the division of other nuclei. In 1882 he devised the terms cytoplasm and nucleoplasm to describe the cell body and nucleus, respectively. Next, he showed that during fertilization in the flowering plants the nucleus is the primary structure concerned in heredity. In 1888 he established that the nuclei of the germ cells of angiosperms undergo meiosis—i.e., a reduction division yielding nuclei with half the number of chromosomes of the original nuclei.

      Strasburger's later work on the upward movement of sap proved that the process is physical rather than physiological. With other outstanding botanists, he wrote Lehrbuch der Botanik (1894; “Textbook of Botany”).

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