Encyclopedia of Earth
Encyclopedia of Earth: On the Origin of Species (Historical E Book)
The complete original text of On the Origin of Species by Charles Darwin.
American Museum of Natural History
American Museum of Natural History: Darwin Manuscripts Project
Background information and slideshow presentation on creating the Origin of Species scientific manuscripts.
Other
The Rise of Evolutionary Biology: Darwin's Ideas
These pages are part of a site called "Evolution," that accompany a textbook by the same name. Mark Ridley is the author. This section is about Darwin, his travels, and his observations that led to "On The Origins Of Species."