The Origin of Species Chapter 13 - Geological Distribution Continued

In which the curious distribution of fresh-water species and the peculiar inhabitants of oceanic islands are examined with a delicate attention to the interplay of dispersal, modification, and the barriers imposed by land and sea. The narrative gently unfolds the nuances of species affinity to nearest mainlands, the absence of certain orders on islands, and the profound influence of migration and natural selection upon the forms we encounter in these isolated realms.