The early origins of the logit model

This paper describes the origins of the logistic function and its history up to its adoption in bio-assay and the beginning of its wider acceptance in statistics, ca. 1950. The function was probably first invented in 1838 to describe population growth by the Belgian mathematician Verhulst, who gave it its name in 1845; but it was rediscovered independently several times over in the next eighty years, both for this purpose and for the description of autocatalytic chemical reactions. Its adoption in an altogether different role in bio-assay has been determined decisively by the individual actions and personal histories of a few scholars: the widespread acceptance of the growth function is due to Pearl and Reed, the general recognition of Verhulst¿s primacy to Yule, and the introduction of the function in bio-assay to Berkson.