Introduction

`On the Negro's Place in Nature' in Memoirs of the Anthropological Society of London, vol. 1 (1863--4)

James Hunt

`Uber den Stammbaum des Menschengeschlechts' in Gesammelte Populaere Vortraege aus dem Gebiete der Entwickelungslehre (1878)

Ernst Haeckel

`Geographie und Anthropologie als Bundesgenossen' in Verhandlungen der Gesellschaft fur Erdkunde zu Berlin (1881)

Gustav Fritsch

`The Origin of Human Races and the Antiquity of Man Deduced from the theory of ``Natural Selection''' in Journal of the Anthropological Society of London, vol. 2 (1864)

Alfred Russel Wallace

`The Aryan Question and Prehistoric Man' in The Nineteenth Century (1890)

Thomas Henry Huxley

La Varieta Umane. Principi e metodo di classificazione (1893)

Giuseppe Sergi

`Rassenbildung und Erblichkeit' in Festschrift fur Adolf Bastian (1896)

Rudolf Virchow