Few biological interactions have deserved so much attention from biologists during the latter part of the 20th century than host-parasite interactions. Parasites seem to throw a special light on the problems of ecology and evolution. Host-parasite interactions should be considered fine-grained biological models through which major changes in ecosystems can be monitored, e.g., global climate change [2,3]. In the following pages I will review as briefly as possible the main pathways that research on the historical biogeography of parasites has traversed ever since the American parasitologist Harold W Manter coined the term that is the subject matter of this chapter, parascript.