Books in Biology (sorted by popularity)
- Darwinism (1889) Alfred Russel Wallace 148 downloads
- Lamarck, the Founder of Evolution: His Life and Work A. S. Packard 144 downloads
- Life History of the Kangaroo Rat Charles Taylor Vorhies and Walter P. Taylor 142 downloads
- Form and Function: A Contribution to the History of Animal Morphology E. S. Russell 141 downloads
- The Human Side of Animals Royal Dixon 136 downloads
- Darwin and Modern Science A. C. Seward 130 downloads
- Ducks at a Distance: A Waterfowl Identification Guide Bob Hines 128 downloads
- The Story of the Living Machine H. W. Conn 125 downloads
- De l'origine des espèces (French) Charles Darwin 117 downloads
- The Minds and Manners of Wild Animals: A Book of Personal Observations William T. Hornaday 114 downloads
- Nouveaux souvenirs entomologiques - Livre II (French) Jean-Henri Fabre 112 downloads
- "Wee Tim'rous Beasties": Studies of Animal life and Character Douglas English 112 downloads
- Text Book of Biology, Part 1: Vertebrata H. G. Wells 111 downloads
- On the Reception of the 'Origin of Species' Thomas Henry Huxley 108 downloads
- Darwin, and After Darwin, Volumes 1 and 3 George John Romanes 107 downloads
- My Studio Neighbors W. Hamilton Gibson 106 downloads
- Nature Near London Richard Jefferies 105 downloads
- Evolution, Old & New Samuel Butler 103 downloads
- The Origin of Species Thomas Henry Huxley 101 downloads
- Love's Meinie: Three Lectures on Greek and English Birds John Ruskin 100 downloads
- Souvenirs entomologiques - Livre I (French) Jean-Henri Fabre 100 downloads
- Species and Varieties, Their Origin by Mutation Hugo de Vries 99 downloads
- Concerning Animals and Other Matters Edward Hamilton Aitken 97 downloads
- Anecdotes of the Habits and Instinct of Animals Mrs. R. Lee 91 downloads
- Facts and Arguments for Darwin Fritz Müller 91 downloads