 At the end of the 19th century, proponents of scientific racism intertwined themselves with eugenics discourses of "degeneration of the race" and "blood heredity".Henceforth, scientific racist discourses could be defined as the combination of polygenism, unilinealism, social Darwinism, and eugenism.They found their scientific legitimacy on physical anthropology, anthropometry, craniometry, phrenology, physiognomy, and others now discredited disciplines in order to formulate racist prejudices.