Claim: Jean Casimir Félix Guyon, born on July 21, 1831, in Saint-Denis, Ile-Bourbon, a French surgeon and urologist, studied medicine in Paris, receiving his doctorate in 1858, and was later a professor of surgical pathology.
Evidence: Jean Casimir Félix Guyon (21 July 1831 – 2 August 1920) was a French surgeon and urologist born in Saint-Denis, Ile-Bourbon (Réunion). He studied medicine in Paris, receiving his doctorate in 1858. He was appointed médecin des hôpitaux in 1864, and was later a professor of surgical pathology (from 1877) and genitourinary surgery (from 1890) at the University of Paris.