Oskar Hertwig

Oscar Hertwig
Oscar Hertwig by Nicola Perscheid
Born	21 April 1849 Friedberg, Hesse
Died	25 October 1922 (1922-10-26) (aged 73) Berlin
Nationality	German
Fields	zoology
Known for	protists

Oscar Hertwig (21 April 1849 in Friedberg – 25 October 1922 in Berlin) was a German zoologist and professor, who also wrote about the theory of evolution circa 1916, over 55 years after Charles Darwin's book The Origin of Species. He 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 1879–1883, 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 1885–1925, at Ludwig Maximilians Universität, where he served the last 40 years of his 50-year career as a professor at 4 universities.

Richard's research focused on protists (the relationship between the nucleus and the plasm = "Kern-Plasma-Relation"), as well as on developmental physiological studies on sea urchins and frogs. He also wrote a leading Zoology textbook.