Oscar Hertwig

Born in 1849 in Friedberg, Hesse, Oscar Hertwig became one of Germany's leading embryologists and zoologists. He studied medicine and natural science, worked in the lively research world of Jena, and later taught anatomy and embryology at the University of Berlin.

He is best known for his studies of fertilization, especially his observation in sea urchins that the nuclei of sperm and egg unite to form a new cell. That finding was a major step in understanding sexual reproduction, and his broader research on cells, tissues, and embryonic development helped shape modern biology.

Hertwig also wrote influential scientific texts and took part in big debates about evolution, heredity, and development. He died in 1922, remembered as a careful observer whose experiments connected microscopic cell processes with the larger story of how life begins.