Matthias Jakob Schleiden (; 5 April 1804 – 23 June 1881) was a German

botanist Botany, also called plant science, is the branch of natural science and biology studying plants, especially Plant anatomy, their anatomy, Plant taxonomy, taxonomy, and Plant ecology, ecology. A botanist or plant scientist is a scientist who s ...

and co-founder of

cell theory In biology, cell theory is a scientific theory first formulated in the mid-nineteenth century, that living organisms are made up of cells, that they are the basic structural/organizational unit of all organisms, and that all cells come from pr ...

, along with

Theodor Schwann Theodor Schwann (; 7 December 181011 January 1882) was a German physician and physiology, physiologist. His most significant contribution to biology is considered to be the extension of cell theory to animals. Other contributions include the d ...

and

Rudolf Virchow Rudolf Ludwig Carl Virchow ( ; ; 13 October 18215 September 1902) was a German physician, anthropologist, pathologist, prehistorian, biologist, writer, editor, and politician. He is known as "the father of modern pathology" and as the founder o ...

. He published some poems and non-scientific work under the pseudonym Ernst.

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. He studied natural science at the

University of Göttingen The University of Göttingen, officially the Georg August University of Göttingen (, commonly referred to as Georgia Augusta), is a Public university, public research university in the city of Göttingen, Lower Saxony, Germany. Founded in 1734 ...

in Göttingen, Germany, but transferred to the

University of Berlin The Humboldt University of Berlin (, abbreviated HU Berlin) is a public research university in the central borough of Mitte in Berlin, Germany. The university was established by Frederick William III on the initiative of Wilhelm von Humbol ...

in 1835 to study plants.

Johann Horkel Johann Horkel (8 September 1769 in Burg auf Fehmarn – 15 November 1846 in Berlin) was a German physician and botanist. From 1787 he studied medicine at the University of Halle, where in 1802 he was named an associate professor. From 1804 to ...

, Schleiden's uncle, encouraged him to study plant embryology. He soon developed his love for botany and cats into a full-time pursuit. Schleiden preferred to study plant structure under the

microscope A microscope () is a laboratory equipment, laboratory instrument used to examine objects that are too small to be seen by the naked eye. Microscopy is the science of investigating small objects and structures using a microscope. Microscopic ...

. 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 The cell nucleus (; : nuclei) is a membrane-bound organelle found in eukaryote, eukaryotic cell (biology), cells. Eukaryotic cells usually have a single nucleus, but a few cell types, such as mammalian red blood cells, have #Anucleated_cells, ...

, discovered in 1831 by the Scottish botanist

Robert Brown Robert Brown may refer to: Robert Brown (born 1965), British Director, Animator and author Entertainers and artists * Washboard Sam or Robert Brown (1910–1966), American musician and singer * Robert W. Brown (1917–2009), American printmaker ...

, and sensed its connection with

cell division Cell division is the process by which a parent cell (biology), cell divides into two daughter cells. Cell division usually occurs as part of a larger cell cycle in which the cell grows and replicates its chromosome(s) before dividing. In eukar ...

. 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 Jews (, , ), or the Jewish people, are an ethnoreligious group and nation, originating from the Israelites of History of ancient Israel and Judah, ancient Israel and Judah. They also traditionally adhere to Judaism. Jewish ethnicity, rel ...

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''. He became a professor of botany at the

University of Dorpat The University of Tartu (UT; ; ) is a public research university located in the city of Tartu, Estonia. It is the national university of Estonia. It is also the largest and oldest university in the country.

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 Frankfurt am Main () is the most populous city in the States of Germany, German state of Hesse. Its 773,068 inhabitants as of 2022 make it the List of cities in Germany by population, fifth-most populous city in Germany. Located in the forela ...

on 23 June 1881. Schleiden-meduse

Evolution

Schleiden was an early advocate of

evolution Evolution is the change in the heritable Phenotypic trait, characteristics of biological populations over successive generations. It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, re ...

. 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 The Transmutation of species and transformism are 18th and early 19th-century ideas about the change of one species into another that preceded Charles Darwin's theory of evolution through natural selection. The French ''Transformisme'' was a ter ...

. He was one of the first German biologists to accept

Charles Darwin Charles Robert Darwin ( ; 12 February 1809 – 19 April 1882) was an English Natural history#Before 1900, naturalist, geologist, and biologist, widely known for his contributions to evolutionary biology. His proposition that all speci ...

's theory of evolution. He has been described as a leading proponent of

Darwinism ''Darwinism'' is a term used to describe a theory of biological evolution developed by the English naturalist Charles Darwin (1809–1882) and others. The theory states that all species of organisms arise and develop through the natural sel ...

in Germany. 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. Schleiden’s popular writings included two volumes of poetry which appeared under the pseudonym “Ernst” in 1858 and 1873. American composer Harriet P. Sawyer set one of his poems to music with her song “Die ersten Tropfen fallen.”

Selected publications

* ''On the Development of the Organization in Phaenogamous Plants'' (1838) * ''The Plant, a Biography'' (1848) Arthur Henfrey">Arthur_Henfrey_(botanist).html" ;"title="ranslated by Arthur Henfrey (botanist)">Arthur Henfrey * * *

References

External links

Short biography and bibliography
in the Virtual Laboratory of the Max Planck Institute for the History of Science * Schwann, Theodor and Schleyden, M. J.
Microscopical researches into the accordance in the structure and growth of animals and plants.
London: Printed for the Sydenham Society, 1847. * * * * {{DEFAULTSORT:Schleiden, Matthias Jakob 1804 births 1881 deaths Burials at Frankfurt Main Cemetery 19th-century German botanists Heidelberg University alumni Scientists from Hamburg Proto-evolutionary biologists Academic staff of the University of Jena Academic staff of the University of Tartu