Illustration from O. Hertwig's book Lehrbuch der Entwicklungsgeschichte des Menschen und der Wirbeltiere (Textbook of developmental history of humans and vertebrates), 1906.
Oscar Hertwig (21 April 1849 in
Friedberg – 25 October 1922 in
Berlin) was a German
embryologist and
zoologist known for his research in
developmental biology and
evolution. Hertwig is credited as the first man to observe sexual reproduction by looking at the cells of sea urchins under the microscope.[1]
Biography
Hertwig was the elder brother of zoologist-professor
Richard Hertwig (1850–1937). The Hertwig brothers were the most eminent scholars of
Ernst Haeckel (and
Carl Gegenbaur) from the
University of Jena. They were independent of Haeckel's philosophical speculations but took his ideas in a positive way to widen their concepts in
zoology. Initially, between 1879 and 1883, they performed embryological studies, especially on the theory of the
coelom (1881), the fluid-filled body cavity. These problems were based on the phylogenetic theorems of Haeckel, i.e. the
biogenic theory (German = biogenetisches Grundgesetz), and the "
gastraea theory".
Within 10 years, the two brothers moved apart to the north and south of
Germany.
Oscar Hertwig later became a professor of
anatomy in 1888 in
Berlin; however, Richard Hertwig had moved 3 years prior, becoming a professor of zoology in
Munich from 1885 to 1925, at
Ludwig Maximilian University, where he served the last 40 years of his 50-year career as a professor at 4 universities.
Hertwig was a leader in the field of comparative and causal animal-developmental history. He also wrote a leading textbook. By studying
sea urchins he proved that fertilization occurs due to the fusion of a sperm and egg cell.[2][3] He recognized the role of the cell nucleus during inheritance and chromosome reduction during
meiosis: in 1876, he published his findings that fertilization includes the penetration of a spermatozoon into an egg cell.
Hermann Fol also observed this in the same year.
Hertwig's experiments with frog eggs revealed the 'long axis rule', or
Hertwig rule. According to this rule, cell divides along its long axis.[4]
In 1885 Hertwig wrote that nuclein (later called
nucleic acid) is the substance responsible not only for fertilization but also for the transmission of hereditary characteristics.[5] This early suggestion was proven correct much later in 1944 by the
Avery–MacLeod–McCarty experiment which showed that this is indeed the role of the nucleic acid
DNA.
While Hertwig was interested in developmental biology and evolution, he was opposed to chance as assumed in
Charles Darwin´s theory. His most important theoretical book was: "Das Werden der Organismen, eine Widerlegung der Darwinschen Zufallslehre" (Jena, 1916) (translation: "The Origin of Organisms – a Refutation of Darwin's Theory of Chance").
Hertwig is known as Oscar Hedwig in the book "Who discovered what when" by David Ellyard.[6] A history of the discovery of fertilization for mammals including scientists like Hertwig and other workers is given by the book "The Mammalian Egg" by Austin.[7]
^Hertwig, Oscar (1884). Das Problem der Befruchtung und der Isotropie des Eies: eine Theorie der Vererbung. Fischer.
^Gribbin, John (2002). The Scientists: A History of Science Told Through the Lives of Its Greatest Inventors. New York: Random House. p. 547 (citing original source Jenaische Zeitschrift für Medizin und Naturwissenschaft, volume 18, p.276).
ISBN978-0812967883.
^Ellyard, David (2017). Who discovered what when? : five hundred years of great scientific discoveries (2 ed.). New Holland. p. 274.
ISBN978-1921517976.
Weindling, P (1980), "Social concepts in anatomy: theories of the cell state of Oscar Hertwig (1849–1922) and Wilhelm Waldeyer (1836–1921).", The Society for the Social History of Medicine Bulletin, vol. 26 (published Jun 1980), pp. 15–7,
PMID11610800
Gras, N; Verchere, M; Santoro, J P (1975), "[The Oscar Hertwig centenary]", Revue d'Odonto-stomatologie, vol. 4, no. 2, pp. 135–40,
PMID1103253
Churchill, F B (1970), "Hertwig, Weismann, and the meaning of reduction division circa 1890.", Isis; an International Review Devoted to the History of Science and Its Cultural Influences, vol. 61, no. 4, pp. 429–57,
doi:
10.1086/350680,
PMID4942056,
S2CID46321527
Cremer, T. 1985. Von der Zellenlehre zur Chromosomentheorie. Springer Vlg., Heidelberg. This German book can be downloaded here
[1].
Krafft, F., and A. Meyer-Abich (ed.). 1970. Große Naturwissenschaftler – Biographisches Lexikon. Fischer Bücherei GmbH, Frankfurt a. M. & Hamburg.
Mol. Cell. Biol.-lecture, Heidelberg, D.-H. Lankenau. Early to recent key-discoveries: From Germline Theory to Modern Gene Modification.
Weindling, Paul. 1991. Darwinism and Social Darwinism in Imperial Germany: The Contribution of the Cell Biologist Oscar Hertwig (1849–1922). Forschungen zur Medizin- und Biologiegeschichte vol. 3, (Stuttgart: G. Fischer in association with Akademie der Wissenschaften und der Literatur Mainz, 1991).
External links
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