ABSTRACT: This paper discusses some correspondence between Robert Schomburgk (1804–1865) and Adolphe Brongniart (1801–1876). Four letters survive, containing information about the history of Schomburgk's collection of fishes and plants from British Guiana, and his herbarium specimens from Dominican Republic and southeast Asia. A study of these letters has enabled us to confirm that Schomburgk supplied the collection of fishes from Guiana now in the Laboratoire d'Ichtyologie, Muséum National d'Histoire Naturelle, Paris. The letters of the German naturalist are an interesting source of information concerning the practice of sale and exchange of natural history collections in the nineteenth century in return for honours.