Born Apr. 21, 1849, in Friedberg; died Oct. 25, 1922, in Berlin. German biologist. Founder and director of the Anatomical Institute of the University of Berlin (1888-1921).
Hertwig’s principal works were in the fields of the morphology of invertebrates, cytology, and embryology. He studied the development of sex cells (established a single scheme for the maturation of ova and spermatozoa) and the phenomenon of fertilization. In collaboration with his brother Richard, Hertwig studied the origin and fate of the middle germ layer in embryonic development and advanced a theory on the formation of the coelom, the secondary body cavity. Hertwig was a pioneer in the use of the experimental method in embryology. Concerning the theory of evolution, he spoke out against certain propositions of C. Darwin, in particular against the recapitulation of ancestors’ characteristics in individual development.
WORKSHandbuch der vergleichenden und experimentellen Entwicklungslehre der Wirbeltiere, vols. 1-3. Jena, 1901-06.
In Russian translation:
Obshchaia biologiia: Kletka i tkani. St. Petersburg, 1911.