For ten years he worked in Breslau (now Wroclaw), becoming director of his own Institute of Embryology in 1879. He was professor at Innsbruck, Austria from 1889–95, then accepted a professorial chair at the Anatomical Institute of the University of Halle, a post he retained until 1921.
Roux's research was based upon the notion of Entwicklungsmechanik or developmental mechanics. His methodology was to interfere with developing embryos and observe the outcome. Roux's investigations were performed mainly on frogs' eggs to research the earliest structures in amphibian development. His goal was to show Darwinian processes at work on the cellular level.
In 1888, Roux published the results of a series of defect experiments in which he took 2 and 4 cell frog embryos and killed half of the cells of each embryo with a hot needle. He reported that they grew into half-embryos and surmised that the separate function of the two cells had already been determined. This led him to propose his "mosaic" theory: after a few cell divisions the embryo would be like a mosaic, each cell playing its own unique part in the entire design.
After a few years Roux's theory was refuted by the studies of his colleague Hans Driesch and later, with more precision, Hans Spemann showed that, as a rule, Driesch's conclusions were correct, but that results like Roux's may be obtained after intervention in certain planes. Despite this early lapse Roux's pioneering mechanical methodology was to prove most fruitful in 20th century biology.
In a remarkable paper, Roux realised the significance of the linear structure of chromosomes. Their splitting into two equal longitudinal halves assured each daughter cell got the same chromosome complement. Therefore, chromosomes were the bearers of heredity. This was a significant event in cytogenetics.
- Der Kampf der Teile im Organismus (1881)
- Über die Entwicklungsmechanik der Organismen (1890)
- Geschichtliche Abhandlung über Entwicklungsmechanik (two volumes, 1895)
- Die Entwicklungsmechanik (1905)
- Terminologie der Entwicklungsmechanik (1912).
- Hamburger, V (1997), "Wilhelm Roux: visionary with a blind spot.", Journal of the history of biology, 30 (2), pp. 229–38, doi:10.1023/A:1004231618837, PMID 11619471
- Ribatti, Domenico (2002), "A milestone in the study of the vascular system: Wilhelm Roux's doctoral thesis on the bifurcation of blood vessels.", Haematologica (published 2002 Jul), 87 (7), pp. 677–8, PMID 12091116 Check date values in:
- Roux W. 1883. Uber die Bedeutung der Kerntheilungsfiguren. Engelmann, Leipzig.
- Harris, Henry 1995. The cells of the body: a history of somatic cell genetics Cold Spring Harbor Laboratory, Plainview N.Y.