The significance of Temminck's work on biogeography: early nineteenth century natural history in Leiden, The Netherlands.

C.J. Temminck, director of the Rijksmuseum van Natuurlijke Historie (now the National Museum of Natural History in Leiden) and a renowned ornithologist, gained his contemporary's respect thanks to the description of many new species and to his detailed monographs on birds. He also published a small number of works on biogeography describing the fauna of the Dutch colonies in South East Asia and Japan. These works are remarkable for two reasons. First, in them Temminck accurately described the species composition of poorly explored regions, like the Sunda Islands and Japan. Secondly, he formulated a new law on the geographical distribution of animals around the globe, based on the parallels he observed between the fauna from Europe, Asia and Japan. The underlying ideas that lead Temminck to this law were the type-concept, which he understood as the ideal morphological plan behind animal form, the unchanging character of the species and a strong belief in nature's divine design. During the first half of the nineteenth century, the type- and the species-concept, the origin and fixity of the species and the meaning of variations aroused heated discussions. When put in the context of his time, Temminck emerges as a scientist whose work was driven by the dominating scientific philosophy of the time in which he lived, under the influence of late eighteenth century natural history and of French empiricists, in particular, the great zoologist and paleontologist Georges Cuvier. Temminck's detailed descriptions of the Dutch East Indian fauna helped the great naturalists after him to understand nature's patterns and to propose comprehensive theories that explain its diversity.