In the same year he busied himself with the formation of a menagerie at that institution.

In 1794, Geoffroy entered into correspondence with Georges Cuvier. Shortly after the appointment of Cuvier as assistant at the Museum d'Histoire Naturelle, Geoffroy received him into his house. The two friends wrote together five memoirs on natural history, one of which, on the classification of mammals, puts forward the idea of the subordination of characters