Matthias Jakob Schleiden

Template:Short description Template:Redirect Template:Infobox scientist Matthias Jakob Schleiden (Template:IPA;<ref>Template:Cite book</ref><ref>Template:Cite book</ref> 5 April 1804 – 23 June 1881) was a German botanist and co-founder of cell theory, along with Theodor Schwann and Rudolf Virchow. He published some poems and non-scientific work under the pseudonym Ernst.<ref name=":0" />

Career

Matthias Jakob Schleiden was born in Hamburg. on 5 April 1804. His father was the municipal physician of Hamburg. Schleiden pursued legal studies graduating in 1827. He then established a legal practice but after a period of emotional depression and attempted suicide, he changed professions. The suicide attempt left a prominent scar across his forehead.<ref name="Mukherjee_song">Template:Cite book</ref>

He studied natural science at the University of Göttingen in Göttingen, Germany, but transferred to the University of Berlin in 1835 to study plants. Johann Horkel, Schleiden's uncle, encouraged him to study plant embryology.<ref>Template:Cite web</ref>

He soon developed his love for botany and cats into a full-time pursuit. Schleiden preferred to study plant structure under the microscope. As a professor of botany at the University of Jena, he wrote Contributions to our Knowledge of Phytogenesis (1838), in which he stated that all plants are composed of cells. Thus, Schleiden and Schwann became the first to formulate what was then an informal belief as a principle of biology equal in importance to the atomic theory of chemistry. He also recognized the importance of the cell nucleus, discovered in 1831 by the Scottish botanist Robert Brown,<ref>Template:Cite web</ref> and sensed its connection with cell division. In 1838, the two scientists M. J. Schleiden and Theodore Schwann formulated a theory about cellular structure which stated, 'All the living organisms are made up of cells and the cell is the fundamental component of living organismus”. In 1885 Rudolf Virchow stated that all cells are formed from pre-existing cells.

Although Schleiden was not Jewish nor a historian by profession, he was noted for his defense of Judaism and against antisemitism, and wrote two works, Die Bedeutung der Juden für die Erhaltung und Wiederbelebung der Wissenschaften im Mittelalter (1877) and Die Romantik des Martyriums bei den Juden im Mittelalter (1878), published in English as The Sciences among the Jews Before and During the Middle Ages and The Importance of the Jews for the Preservation and Revival of Learning during the Middle Ages. <ref>Template:Cite journal</ref>

He became a professor of botany at the University of Dorpat in 1863. He concluded that all plant parts are made of cells and that an embryonic plant organism arises from one cell.

He died in Frankfurt am Main on 23 June 1881.<ref>Mathias Jacob Schleiden Template:Webarchive, Encyclopædia Britannica</ref>

File:Schleiden-meduse.jpg

Die Entwickelung der Meduse ("The Development of the Medusæ"), in Schleiden's Das Meer

Evolution

Schleiden was an early advocate of evolution. In a lecture on the "History of the Vegetable World" published in his book Die Pflanze und ihr Leben ("The Plant: A Biography") (1848) was a passage that embraced the transmutation of species.<ref>"Matthias Jakob Schleiden (1804-1881)" Template:Webarchive. The Arnold Arboretum of Harvard University.</ref> He was one of the first German biologists to accept Charles Darwin's theory of evolution. He has been described as a leading proponent of Darwinism in Germany.<ref>Glick, Thomas F. (1988). The Comparative Reception of Darwinism. University of Chicago Press. p. 83. Template:ISBN</ref>

With Die Pflanze und ihr Leben, reprinted six times by 1864, and his Studien: Populäre Vorträge ("Studies: Popular Lectures"), both written in a way that was accessible to lay readers, Schleiden contributed to creating a momentum for popularizing science in Germany.<ref>Andreas W. Daum, Wissenschaftspopularisierung im 19. Jahrhundert: Bürgerliche Kultur, naturwissenschaftliche Bildung und die deutsche Öffentlichkeit, 1848–1914. Munich: Oldenbourg, 1998, pp. 252, 256, 262, 288, 509.</ref>

Schleiden’s popular writings included two volumes of poetry which appeared under the pseudonym “Ernst” in 1858 and 1873.<ref name=":0">Template:Cite journal</ref> American composer Harriet P. Sawyer set one of his poems to music with her song “Die ersten Tropfen fallen.”<ref>Template:Cite web</ref>