Walther Flemming (21 April 1843 – 4 August 1905) was a German
biologist
A biologist is a scientist who conducts research in biology. Biologists are interested in studying life on Earth, whether it is an individual Cell (biology), cell, a multicellular organism, or a Community (ecology), community of Biological inter ...
and a founder of
cytogenetics
Cytogenetics is essentially a branch of genetics, but is also a part of cell biology/cytology (a subdivision of human anatomy), that is concerned with how the chromosomes relate to cell behaviour, particularly to their behaviour during mitosis an ...
.
He was born in Sachsenberg (now part of
Schwerin
Schwerin (; Mecklenburgisch dialect, Mecklenburgian Low German: ''Swerin''; Latin: ''Suerina'', ''Suerinum'') is the Capital city, capital and List of cities and towns in Germany, second-largest city of the northeastern States of Germany, German ...
) as the fifth child and only son of the
psychiatrist
A psychiatrist is a physician who specializes in psychiatry, the branch of medicine devoted to the diagnosis, prevention, study, and treatment of mental disorders. Psychiatrists are physicians and evaluate patients to determine whether their sy ...
Carl Friedrich Flemming
Carl Friedrich Flemming (27 December 1799 – 27 January 1880) was a German psychiatrist born in Jüterbog. He was the father of cellular biology, cellular biologist Walther Flemming (1843-1905).
After receiving his medical doctorate from Berlin, ...
(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
Heinrich Friedrich Wilhelm Seidel (25 June 1842, Perlin, Germany, Perlin, Grand Duchy of Mecklenburg-Schwerin, Mecklenburg-Schwerin – 7 November 1906, Berlin) was a German engineer, poet and writer.
Life
Seidel was the son of a pastor and st ...
.
Career
Flemming trained in
medicine
Medicine is the science and practice of caring for a patient, managing the diagnosis, prognosis, prevention, treatment, palliation of their injury or disease, and promoting their health. Medicine encompasses a variety of health care pract ...
at the University of
Prague
Prague ( ; cs, Praha ; german: Prag, ; la, Praga) is the capital and largest city in the Czech Republic, and the historical capital of Bohemia. On the Vltava river, Prague is home to about 1.3 million people. The city has a temperate ...
, graduating in 1868. Afterwards, he served in 1870–71 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
Anatomy () is the branch of biology concerned with the study of the structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old science, having its ...
at the
University of Kiel
Kiel University, officially the Christian-Albrecht University of Kiel, (german: Christian-Albrechts-Universität zu Kiel, abbreviated CAU, known informally as Christiana Albertina) is a university in the city of Kiel, Germany. It was founded in ...
. He became the director of the Anatomical Institute and stayed there until his death.
With the use of
aniline
Aniline is an organic compound with the formula C6 H5 NH2. Consisting of a phenyl group attached to an amino group, aniline is the simplest aromatic amine
In organic chemistry, an aromatic amine is an organic compound consisting of an aroma ...
dyes he was able to find a structure which strongly absorbed
basophilic
Basophilic is a technical term used by pathologists. It describes the appearance of cells, tissues and cellular structures as seen through the microscope after a histological section has been stained with a basic dye. The most common such dye i ...
dyes, which he named
chromatin
Chromatin is a complex of DNA and protein found in eukaryotic cells. The primary function is to package long DNA molecules into more compact, denser structures. This prevents the strands from becoming tangled and also plays important roles in r ...
. He identified that chromatin was correlated to threadlike structures in the
cell nucleus
The cell nucleus (pl. nuclei; from Latin or , meaning ''kernel'' or ''seed'') is a membrane-bound organelle found in eukaryotic cells. Eukaryotic cells usually have a single nucleus, but a few cell types, such as mammalian red blood cells, h ...
– the
chromosome
A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins are ...
s (meaning ''coloured bodies''), which were named thus later by German anatomist
Wilhelm von Waldeyer-Hartz
Heinrich Wilhelm Gottfried von Waldeyer-Hartz (6 October 1836 – 23 January 1921) was a German anatomist, known for summarizing neuron theory and for naming the chromosome. He is also remembered by anatomical structures of the human body which ...
(1841–1923). The Belgian scientist
Edouard Van Beneden (1846–1910) had also observed them, independently. The centrosome was discovered jointly by Walther Flemming in 1875 and
Edouard Van Beneden in 1876.
Flemming investigated the process of
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 ...
and the distribution of chromosomes to the daughter nuclei, a process he called
mitosis
In cell biology, mitosis () is a part of the cell cycle in which replicated chromosomes are separated into two new nuclei. Cell division by mitosis gives rise to genetically identical cells in which the total number of chromosomes is mainta ...
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
Studies that are ''in vivo'' (Latin for "within the living"; often not italicized in English) are those in which the effects of various biological entities are tested on whole, living organisms or cells, usually animals, including humans, and ...
'' and in stained preparations, using as the source of biological material the
fin
A fin is a thin component or appendage attached to a larger body or structure. Fins typically function as foils that produce lift or thrust, or provide the ability to steer or stabilize motion while traveling in water, air, or other fluids. Fin ...
s and
gill
A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they are ...
s of
salamander
Salamanders are a group of amphibians typically characterized by their lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults. All ten ...
s. 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'').
![Zellsubstanz-Kern-Kerntheilung](https://upload.wikimedia.org/wikipedia/commons/6/6d/Zellsubstanz-Kern-Kerntheilung.jpg)
Flemming is also known for his philanthropy. He weekly fed those who were homeless, donating every year, 20% of his salary to homeless shelters. He taught especially young children who were too poor to attend school about mathematics and science.
Flemming was unaware of the work of
Gregor Mendel
Gregor Johann Mendel, Augustinians, OSA (; cs, Řehoř Jan Mendel; 20 July 1822 – 6 January 1884) was a biologist, meteorologist, mathematician, Augustinians, Augustinian friar and abbot of St Thomas's Abbey, Brno, St. Thomas' Abbey in Brà ...
(1822–84) on
heredity
Heredity, also called inheritance or biological inheritance, is the passing on of traits from parents to their offspring; either through asexual reproduction or sexual reproduction, the offspring cells or organisms acquire the genetic inform ...
, 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.
The Science Channel
Science Channel (often simply branded as Science; abbreviated to SCI) is an American pay television channel owned by Warner Bros. Discovery. The channel features programming focusing on science related to wilderness survival, engineering, manu ...
named Flemming's discovery of mitosis and chromosomes as one of the 100 most important scientific discoveries of all time, and one of the 10 most important discoveries in
cell biology
Cell biology (also cellular biology or cytology) is a branch of biology that studies the structure, function, and behavior of cells. All living organisms are made of cells. A cell is the basic unit of life that is responsible for the living and ...
.
Flemming's name is honoured by a medal awarded by the German Society for Cell Biology (Deutsche Gesellschaft für Zellbiologie).
References
Further reading
*
*
*
*
* and Reprinted in ''J. Cell Biol.'' 25:581–589 (1965).
*Flemming, W. "Zur Kenntniss der Zelle und ihrer Theilungs-Erscheinungen". In: ''Schriften des Naturwissenschaftlichen Vereins für Schleswig-Holstein'' 3 (1878), 23–27. (Reprinted in '')''
* 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. .
External links
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.
{{DEFAULTSORT:Flemming, Walther
1843 births
1905 deaths
People from Schwerin
People from the Grand Duchy of Mecklenburg-Schwerin
19th-century German biologists
German geneticists
Cytogenetics
Members of the Royal Society of Sciences in Uppsala