 Trautmann considers Risley, along with the philologist Max Müller, to have been leading proponents of this idea which Trautmann notes, however, that the convergence of their theories was not a deliberate collaboration.In the same year, 1891, the four volumes of "The Tribes and Castes of Bengal" were published.These contained the results of the Bengal survey, with two volumes comprising an "Ethnographical Glossary", and a further two being of "Anthropometric Data".