this picture shows Walther Flemming
|Born||21 April 1843
|Died||4 August 1905
|Alma mater||University of Rostock|
|Known for||Cytogenetics, mitosis, chromosomes, chromatin|
He was born in Sachsenberg (now part of Schwerin) as the fifth child and only son of the psychiatrist Carl Friedrich Flemming (1799–1880) and his second wife, Auguste Winter. He graduated from the Gymnasium der Residenzstadt, where one of his colleagues and lifelong friends was writer Heinrich Seidel.
Flemming trained in medicine at the University of Rostock, graduating in 1868. Afterwards. He served in 1870–1871 as a military physician in the Franco-Prussian War. From 1873 to 1876 he worked as a teacher at the University of Prague. In 1876 he accepted a post as a professor of anatomy at the University of Kiel. He became the director of the Anatomical Institute and stayed there until his death.
Making use of aniline dyes he was able to find a structure which strongly absorbed basophilic dyes, which he named chromatin. He identified that chromatin was correlated to threadlike structures in the cell nucleus— the chromosomes (meaning coloured body), which were thus named later on by German anamist Wilhelm von Waldeyer-Hartz (1841–1923). The Belgian scientist Edouard Van Beneden (1846–1910) had also observed them, independently.
Flemming investigated the process of cell division and the distribution of chromosomes to the daughter nuclei, a process he called mitosis from the Greek word for thread. However, he did not see the splitting into identical halves, the daughter chromatids. He studied mitosis both in vivo and in stained preparations, using as the source of biological material the fins and gills of salamanders. These results were published first in 1878  and in 1882 in the seminal book Zellsubstanz, Kern und Zelltheilung (1882; Cell substance, nucleus and cell division). On the basis of his discoveries, Flemming surmised for the first time that all cell nuclei came from another predecessor nucleus (he coined the phrase omnis nucleus e nucleo, after Virchow's omnis cellula e cellula).
Flemming was unaware of Gregor Mendel's (1822–1884) work on heredity, so he did not make the connection between his observations and genetic inheritance. Two decades would pass before the significance of Flemming's work was truly realized with the rediscovery of Mendel's rules. His discovery of mitosis and chromosomes is considered one of the 100 most important scientific discoveries of all times, and one of the 10 most important discoveries in cell biology (together with August Weismann's (1834–1914) discovery of meiosis, Theodor Schwann (1808–1890) and Matthias Schleiden's (1804–1881) cell theory and Alfred Sturtevant's (1866–1945) first genetic maps).
Flemming's name is honoured by a medal awarded by the German Society for Cell Biology (Deutschen Gesellschaft für Zellbiologie).
- Flemming, W. (1878). "Zur Kenntniss der Zelle und ihrer Theilungs-Erscheinungen" (PDF). Schriften des Naturwissenschaftlichen Vereins für Schleswig-Holstein 3: 23–27.
- 100 Greatest Discoveries – Carnegie Institution. carnegieinstitution.org
- The Science Channel :: 100 Greatest Discoveries: Biology. science.discovery.com
Further reading 
|Wikimedia Commons has media related to: Walther Flemming|
- Lukács (1981). "Walter Flemming, discoverer of chromatin and mitotic cell division". Orvosi hetilap 122 (6): 349–50. PMID 7015236.
- Latronico (2000). "Heredity, constitution and diathesis". Minerva pediatrica 52 (1–2): 81–115. PMID 10829597.
- Breathnach (1982). "Biographical sketches No. 18—Flemming". Irish medical journal 75 (6): 177. PMID 7050007.
- Paweletz (2001). "Walther Flemming: pioneer of mitosis research". Nature reviews. Molecular cell biology 2 (1): 72–5. doi:10.1038/35048077. PMID 11413469.
- Flemming, Walther (1879). "Beitrage zur Kenntniss der Zelle und ihrer Lebenserscheinungen". Archiv für Mikroskopische Anatomie 16 (1): 302. doi:10.1007/BF02956386. and Flemming, Walther (1880). "Beiträge zur Kenntniss der Zelle und Ihrer Lebenserscheinungen". Archiv für Mikroskopische Anatomie 18 (1): 151. doi:10.1007/BF02952594. Reprinted in J. Cell Biol. 25:581–589 (1965).[verification needed]
- Flemming, W. Zur Kenntniss der Zelle und ihrer Theilungs-Erscheinungen. In: Schriften des Naturwissenschaftlichen Vereins für Schleswig-Holstein 3 (1878), 23–27. (Reprinted in "Zir Kenntniss der Zelle und ihrer Teilungs-Erscheinungen".)
- Carlson, E.A. The Analysis of Mitosis Shifts Attention to the Chromosomes. In: Mendel's Legacy. The Origins of Classical Genetics. p. 24-5, CSHL Press, 2004. ISBN 0-87969-675-3.
- Walther Flemming Biography. Lasker Labs
- Zellsubstanz, Kern und Zelltheilung. Original text of the book, as PDF (In German).
- Walter Flemming Medaille. In PDF, in German.
- Hardy, P. A., Zacharias, H. (2008): Walther Flemming und die Mitose: Der Beitrag seiner ersten Kieler Jahre. Schr. Naturwiss. Ver. Schlesw.-Holst. 70, 3–15. Paper about his first description of mitosis. In German. "Walther Flemming und die Mitose: Der Beitrag seiner ersten Kieler Jahre" (PDF). Retrieved 2010-03-16.