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

Rudolf Virchow Rudolf Ludwig Carl Virchow (; or ; 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 founde ...

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. He studied natural science at the

University of Göttingen The University of Göttingen, officially the Georg August University of Göttingen, (german: Georg-August-Universität Göttingen, known informally as Georgia Augusta) is a public research university in the city of Göttingen, Germany. Founded i ...

in Göttingen, Germany, but transferred to the

University of Berlin The Humboldt University of Berlin (german: link=no, Humboldt-Universität zu Berlin, abbreviated HU Berlin) is a public research university in the central borough of Mitte in Berlin, Germany. The university was established by Frederick Will ...

in 1835 to study plants. Johann Horkel, 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 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 means being invisibl ...

. 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, and sensed its connection with

cell division Cell division is the process by which a parent 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 eukaryotes, there ar ...

. 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 Frankfurt, officially Frankfurt am Main (; Hessian dialects, Hessian: , "Franks, Frank ford (crossing), ford on the Main (river), Main"), is the most populous city in the States of Germany, German state of Hesse. Its 791,000 inhabitants as o ...

on 23 June 1881. Schleiden-meduse

Evolution

Schleiden was an early advocate of

evolution Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation ...

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

. 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 theory of biological evolution developed by the English naturalist Charles Darwin (1809–1882) and others, stating that all species of organisms arise and develop through the natural selection of small, inherited variations that ...

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.

Andreas W. Daum Andreas W. Daum is a German-American historian who specializes in modern German and transatlantic history, as well as the history of knowledge and global exploration. Daum received his Ph.D. summa cum laude in 1995 from the Ludwig Maximilian Unive ...

, ''Wissenschaftspopularisierung im 19. Jahrhundert: Bürgerliche Kultur, naturwissenschaftliche Bildung und die deutsche Öffentlichkeit, 1848–1914''. Munich: Oldenbourg, 1998, pp. 252, 256, 262, 288, 509.

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 University of Jena faculty University of Tartu faculty