[Isidore Geoffroy Saint-Hilaire (1805-1861)].

Isidore Geoffroy Saint-Hilaire studied anatomy and congenital abnormalities in humans [2] and other animals in nineteenth century France. Under the tutelage of his father, Étienne Geoffroy Saint-Hilaire, Isidore compiled and built on his father's studies of individuals with developmental malformations, then called monstrosities. In 1832, Isidore published Histoire générale et particulière des anomalies de l'organisation chez l'homme et les animaux (General and Particular History of Structural Monstrosities in Man and Animals), in which he defined the term teratology [3] as the study of birth defects [4] and deformities. Isidore Geoffroy Saint-Hilaire helped establish teratology [3] as a branch of scientific study.