Books in Biology (sorted by popularity)
- Darwin and Modern Science A. C. Seward 131 downloads
- The Human Side of Animals Royal Dixon 128 downloads
- The Life-Story of Insects George H. Carpenter 125 downloads
- Lamarck, the Founder of Evolution: His Life and Work A. S. Packard 125 downloads
- Darwinism (1889) Alfred Russel Wallace 124 downloads
- The Story of the Living Machine H. W. Conn 123 downloads
- Life History of the Kangaroo Rat Charles Taylor Vorhies and Walter P. Taylor 120 downloads
- Ducks at a Distance: A Waterfowl Identification Guide Bob Hines 113 downloads
- De l'origine des espèces (French) Charles Darwin 109 downloads
- Text Book of Biology, Part 1: Vertebrata H. G. Wells 104 downloads
- My Studio Neighbors W. Hamilton Gibson 102 downloads
- On the Reception of the 'Origin of Species' Thomas Henry Huxley 93 downloads
- The Origin of Species Thomas Henry Huxley 93 downloads
- "Wee Tim'rous Beasties": Studies of Animal life and Character Douglas English 92 downloads
- Species and Varieties, Their Origin by Mutation Hugo de Vries 91 downloads
- Ohio Biological Survey, Bull. 10, Vol. 11, No. 6 Bruce Fink and Leafy Jane Corrington Hilker 90 downloads
- Evolution, Old & New Samuel Butler 89 downloads
- Darwin, and After Darwin, Volumes 1 and 3 George John Romanes 85 downloads
- Nature Near London Richard Jefferies 85 downloads
- Facts and Arguments for Darwin Fritz Müller 84 downloads
- The Minds and Manners of Wild Animals: A Book of Personal Observations William T. Hornaday 84 downloads
- Nouveaux souvenirs entomologiques - Livre II (French) Jean-Henri Fabre 83 downloads
- Anecdotes of the Habits and Instinct of Animals Mrs. R. Lee 80 downloads
- Concerning Animals and Other Matters Edward Hamilton Aitken 79 downloads
- Parasiten der Honigbiene (German) Eduard Philibert Assmuss 77 downloads