Habitat dioramas depicting ecological relations between organisms and their natural environments have become the preferred mode of museum display in most natural history museums in North America and Europe. Dioramas emerged in the late nineteenth century as an alternative mode of museum installation from taxonomically arranged cases. We suggest that this change was closely connected to the emergence of a biogeographical framework rooted in evolutionary theory and positing the existence of distinct biogeographical zones. We tie the history of dioramas to (...) earlier visual resources such as the thematic images that Wallace introduced to illustrate his 1876 Geographical Distribution of Animals. These images were unique in their time because each of them simultaneously depicted animals from several different taxa, rather than only one, as well as the ecological relations between animals and their habitats. Both, visually and with respect to their function within biogeography, these images presaged the habitat dioramas that came shortly afterwards. Not coincidentally, Wallace explicitly advocated the use of dioramas for museum display in ongoing debates on museum reform. Wallace 's suggestions were put into practice by committed evolutionists such as Gottlieb von Koch who pioneered the diorama installation in the Grand Ducal Museum in Darmstadt in 1906. As in Wallace 's illustrations, Koch's dioramas were designed to respresent biogeographical zones. This paper explores the function of these visual displays of biogeographical relations. It argues that, in both the scientific and public realms, biogeogaphical zones were defined and constructed by visual means; recourse to visual representation was more than a method of communication. (shrink)