Books in Biology (sorted by popularity)
- The Wonders of Instinct: Chapters in the Psychology of Insects Jean-Henri Fabre 175 downloads
- On the Genesis of Species St. George Jackson Mivart 158 downloads
- Darwin and Modern Science A. C. Seward 155 downloads
- Lamarck, the Founder of Evolution: His Life and Work A. S. Packard 154 downloads
- Life History of the Kangaroo Rat Charles Taylor Vorhies and Walter P. Taylor 153 downloads
- The Human Side of Animals Royal Dixon 145 downloads
- "Wee Tim'rous Beasties": Studies of Animal life and Character Douglas English 144 downloads
- Development of the Digestive Canal of the American Alligator A. M. Reese 143 downloads
- De l'origine des espèces (French) Charles Darwin 134 downloads
- Text Book of Biology, Part 1: Vertebrata H. G. Wells 134 downloads
- On the Reception of the 'Origin of Species' Thomas Henry Huxley 132 downloads
- Evolution, Old & New Samuel Butler 131 downloads
- My Studio Neighbors W. Hamilton Gibson 130 downloads
- Darwin, and After Darwin, Volumes 1 and 3 George John Romanes 127 downloads
- The Story of the Living Machine H. W. Conn 127 downloads
- Ducks at a Distance: A Waterfowl Identification Guide Bob Hines 127 downloads
- Love's Meinie: Three Lectures on Greek and English Birds John Ruskin 117 downloads
- Species and Varieties, Their Origin by Mutation Hugo de Vries 116 downloads
- Nouveaux souvenirs entomologiques - Livre II (French) Jean-Henri Fabre 115 downloads
- The Origin of Species Thomas Henry Huxley 114 downloads
- The Minds and Manners of Wild Animals: A Book of Personal Observations William T. Hornaday 111 downloads
- Nature Near London Richard Jefferies 105 downloads
- Concerning Animals and Other Matters Edward Hamilton Aitken 105 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 99 downloads
- Essays on early ornithology and kindred subjects James Roxburgh McClymont 99 downloads