ABSTRACT
When on board H. M. S. Beagle, as naturalist, author was much struck with certain facts in the distribution of the inhabitants of South America, and in the geological relations of the present to the past inhabitants of that continent. These facts seemed to throw some light on the Origin of Species that mystery of mysteries, as it has been called by one of our greatest philosophers. The author have more especially been induced to do this, as Mr Wallace, who is now studying the Natural History of the Malay Archipelago, has arrived at almost exactly the same general conclusions that author have on the Origin of Species. Sir C. Lyell and Dr Hooker, who both knew of my work the latter having read my sketch of 1844 honoured me by thinking it advisable to publish, with Mr Wallace's excellent memoir, some brief extracts from her manuscripts.
