Carl Wilhelm Nägeli, best known in the history of genetics as the scientist whose correspondence with Gregor Mendel (1822-1884) rescued Mendel's important work on inheritance from oblivion, also added to the knowledge of cells, sperm, and hybridization. Born in Kilchberg, Switzerland, Nägeli attended the Zürich Gymnasium. Because his father, a physician, intended him for a career in medicine, he entered the University of Zürich as a medical student in 1836, but upon hearing the lectures of Lorenz Oken (1779-1851), his interests shifted toward natural science. Influential too in changing Nägeli's plans was Albert von Kölliker (1817-1905), his schoolmate at both the gymnasium and the university. Nägeli transferred to the University of Geneva to study botany under Alphonse de Candolle (1806-1893), but received his Ph.D. at Zürich in 1840 with a dissertation on the...