Books in Biology (sorted by popularity)
- Lamarck, the Founder of Evolution: His Life and Work A. S. Packard 120 downloads
- Fathers of Biology Charles McRae 116 downloads
- On the Genesis of Species St. George Jackson Mivart 111 downloads
- Development of the Digestive Canal of the American Alligator A. M. Reese 109 downloads
- Darwin and Modern Science A. C. Seward 109 downloads
- Evolution, Old & New Samuel Butler 108 downloads
- The Story of the Living Machine H. W. Conn 107 downloads
- Text Book of Biology, Part 1: Vertebrata H. G. Wells 107 downloads
- Life History of the Kangaroo Rat Charles Taylor Vorhies and Walter P. Taylor 106 downloads
- The Origin of Species Thomas Henry Huxley 104 downloads
- "Wee Tim'rous Beasties": Studies of Animal life and Character Douglas English 99 downloads
- My Studio Neighbors W. Hamilton Gibson 97 downloads
- Ducks at a Distance: A Waterfowl Identification Guide Bob Hines 94 downloads
- Darwin, and After Darwin, Volumes 1 and 3 George John Romanes 93 downloads
- De l'origine des espèces (French) Charles Darwin 93 downloads
- Love's Meinie: Three Lectures on Greek and English Birds John Ruskin 88 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 87 downloads
- Species and Varieties, Their Origin by Mutation Hugo de Vries 84 downloads
- Contributions to the Theory of Natural Selection Alfred Russel Wallace 83 downloads
- The Minds and Manners of Wild Animals: A Book of Personal Observations William T. Hornaday 82 downloads
- Facts and Arguments for Darwin Fritz Müller 82 downloads
- On the Reception of the 'Origin of Species' Thomas Henry Huxley 81 downloads
- Anecdotes of the Habits and Instinct of Animals Mrs. R. Lee 81 downloads
- Parasiten der Honigbiene (German) Eduard Philibert Assmuss 79 downloads
- A Theory of Creation: A Review of 'Vestiges of the Natural History of Creation' Francis Bowen 76 downloads