Background
Félix Mesnil was born on December 12, 1868, in Omonville-la-petite, Basse-Normandie, France. His family had been farmers in Normandy for several generations.
45 Rue d'Ulm, 75005 Paris, France
At the age of eighteen, Mesnil was accepted by both the École Polytechnique and the École Normale Supérieure; he chose the latter because of the interest in natural history he had developed during his boyhood. He passed the agrégation in the natural sciences in 1891 and obtained his doctorate in 1895 with a work on the resistance of lower vertebrates to microbial invasions. After passing the agrégation he spent several months at universities in central Europe.
44 Boulevard Saint-Michel, 75006 Paris, France
Mesnil studied at the Lycée Saint-Louis in Paris.
45 Rue d'Ulm, 75005 Paris, France
At the age of eighteen, Mesnil was accepted by both the École Polytechnique and the École Normale Supérieure; he chose the latter because of the interest in natural history he had developed during his boyhood. He passed the agrégation in the natural sciences in 1891 and obtained his doctorate in 1895 with a work on the resistance of lower vertebrates to microbial invasions. After passing the agrégation he spent several months at universities in central Europe.
Félix Mesnil was a member of the French Academy of Sciences.
Félix Mesnil was a member of the Zoological Society of France.
Félix Mesnil was a member of the National Academy of Medicine.
Félix Mesnil was a member of the Académie des Sciences Coloniales.
Félix Mesnil was a member of the Société de Pathologie Exotique.
biologist Botanist mycologist scientist Zoologist algologist
Félix Mesnil was born on December 12, 1868, in Omonville-la-petite, Basse-Normandie, France. His family had been farmers in Normandy for several generations.
Mesnil attended the school in his village. One of his uncles, a physician in the navy, recognized Mesnil’s exceptional ability and arranged for him to enter the lycée in Cherbourg and then the Lycée Saint-Louis in Paris. At the age of eighteen, he was accepted by both the École Polytechnique and the École Normale Supérieure; he chose the latter because of the interest in natural history he had developed during his boyhood. He passed the agrégation in the natural sciences in 1891 and obtained his doctorate in 1895 with a work on the resistance of lower vertebrates to microbial invasions. After passing the agrégation he spent several months at universities in central Europe.
Upon returning from Central Europe, Félix Mesnil entered the Institut Pasteur and remained there throughout his career. While serving as assistant and secretary to Pasteur, he began to work in Metchnikoff’s laboratory, where he acquired experimental technique. Mesnil became agrégé préparateur in 1892, laboratory director in 1898, and professor in 1910.
Mesnil’s work was varied, much of it oriented toward general biology; important memoirs dealt with systematic, ecological, and ethological zoology. For more than thirty years, during summer vacations Mesnil had the opportunity to study - first alone and then, beginning in 1914, with his brother-in-law Caullery - the fauna of St. Martin Cove, near the Cap de la Hague, and of the neighboring coasts. This research resulted in the description of many new genera and species of annelids, crustaceans, enteropneusts, turbellarians, Orthonectida, and protozoans. A great number of investigations were devoted to the annelid polychaetes - to their morphology, in order to establish their phylogenetic relationships; to their sexual maturity (epitokous forms); and to their asexual reproduction (schizogenesis, regeneration). Mesnil, who was interested in parasitism, discovered that condition in the Monstrillidae. With Caullery, he described Xenocoeloma brumpti, a parasite of Polycirrus arenivorus; the two scientists furnished a precise analysis of its morphology, of the penetration of the larva into the annelid, and of its complex development. They also studied isopod parasites of sea acorns and spheromes; Fecampia (turbellarian rhabdocoeles that are internal parasites of crustaceans); and the Orthonectida and their life cycle.
Alone or with Caullery and A. Laveran (the latter discovered the hematozoon of malaria), Mesnil examined the parasitic protozoans: gregarines, coccidia, Myxosporidia, Microsporidia, infusoria, and flagellates. From 1900 to 1916 Mesnil was concerned especially with the trypanosomes and trypanosomiases; chemotherapy, determination of the species, experimental constitution of heritable strains, infectious power and virulence, reactions of the organism, and the resistance of certain strains to medicines and serums. He was also interested in natural and acquired immunity. He and Laveran devised the test that bears their names for detecting the specific identity of the trypanosomes.
Mesnil reported on many works in microbiology and general biology for various French journals. With G. Bertrand, A. Besredka, Amédée Borrel C. Delezenne, and A. C. Marie he founded the Bulletin de l’Institut Pasteur and he was also its editor.
Among Mesnil’s students were E. Roubaud, E. Chalton, A. Lwof, and S. Volkonsky.
Mesnil belonged to the Académie des Sciences (1921), the Académie de Médecine, and (as a founding member) the Académie des Sciences Coloniales. In 1907 he participated in founding the Société de Pathologie Exotique, of which he was secretary-general (1908-1920), then vice-president and president (1924-1927).
Kind and easily approachable, Mesnil gave advice and support to everyone.
There is no information on whether Félix Mesnil was ever married or had any children.