Books in Biology (sorted by popularity)
- Birds in Town & Village W. H. Hudson 115 downloads
- What is Darwinism? Charles Hodge 114 downloads
- The Variation of Animals and Plants under Domestication Charles Darwin 113 downloads
- Development of the Digestive Canal of the American Alligator A. M. Reese 113 downloads
- Text Book of Biology, Part 1: Vertebrata H. G. Wells 112 downloads
- Evolution, Old & New Samuel Butler 112 downloads
- The Story of the Living Machine H. W. Conn 108 downloads
- Darwin and Modern Science A. C. Seward 107 downloads
- My Studio Neighbors W. Hamilton Gibson 103 downloads
- Darwin, and After Darwin, Volumes 1 and 3 George John Romanes 102 downloads
- The Origin of Species Thomas Henry Huxley 99 downloads
- Life History of the Kangaroo Rat Charles Taylor Vorhies and Walter P. Taylor 95 downloads
- "Wee Tim'rous Beasties": Studies of Animal life and Character Douglas English 91 downloads
- Ducks at a Distance: A Waterfowl Identification Guide Bob Hines 91 downloads
- De l'origine des espèces (French) Charles Darwin 90 downloads
- Love's Meinie: Three Lectures on Greek and English Birds John Ruskin 87 downloads
- A Critical Examination of the Position of Mr. Darwin's Work, "On the Origin of Species," in Relation to the Complete Theory of the Causes of the Phenomena of Organic Nature Thomas Henry Huxley 84 downloads
- Anecdotes of the Habits and Instinct of Animals Mrs. R. Lee 83 downloads
- Parasiten der Honigbiene (German) Eduard Philibert Assmuss 82 downloads
- Contributions to the Theory of Natural Selection Alfred Russel Wallace 81 downloads
- Facts and Arguments for Darwin Fritz Müller 75 downloads
- On the Reception of the 'Origin of Species' Thomas Henry Huxley 72 downloads
- Species and Varieties, Their Origin by Mutation Hugo de Vries 71 downloads
- Essays on early ornithology and kindred subjects James Roxburgh McClymont 70 downloads
- The Minds and Manners of Wild Animals: A Book of Personal Observations William T. Hornaday 68 downloads