The notion of a distinct northern European race was also rejected by several anthropologists on craniometric grounds. German anthropologist Rudolf Virchow attacked the claim following a study of craniometry, which gave surprising results according to contemporary scientific racist theories on the "Aryan race." During the 1885 Anthropology Congress in Karlsruhe, Virchow denounced the "Nordic mysticism," while Josef Kollmann, a collaborator of Virchow, stated that the people of Europe, be they German, Italian, English or French, belonged to a "mixture of various races," furthermore declaring that the "results of craniology" led to "struggle against any theory concerning the superiority of this or that European race".