An important early researcher in immunology, Elie Metchnikoff was born in Kharkov, Russia, on May 16, 1845. His father was an officer of the Imperial Guard. His mother was the daughter of a Jewish writer, and she encouraged her son's interest in natural sciences. After graduating from the University of Kharkov in 1864, Metchnikoff continued his studies in Germany, then returned to Russia and earned his Ph.D. from the University of St. Petersburg in 1867. Metchnikoff's early career was difficult. His first faculty positions, at the University of Odessa beginning in 1862 and at St. Petersburg in 1868, were marred by difficult working conditions and severe eyestrain. After his first wife died in 1873, Metchnikoff attempted suicide. Thanks to a happy and financially successful second marriage, Metchnikoff became financially independent and moved to Messina, Italy, in 1882 to devote himself to research. There, he made his great discovery.

In 1865, Metchnikoff had studied roundworms for the...