Natural history History 331 Description and travel 276 Travel 133 Ecology 92 Pre-Linnean works 90 Nature in literature 83 mer ... Science 74 Naturalists 70 Environmental conditions 61 Nature 54 Social life and customs 53 Human ecology 50 Knowledge and learning 48 History and criticism 47 Sciences naturelles 45 Biology 42 Zoology 40 Discovery and exploration 35 natural sciences 34 Geology 33 Indians of North America 30 Manners and customs 30 Homes and haunts 29 Natural History 28 Philosophy 28 Discoveries in geography 27 Birds 26 Intellectual life 26 Animals 25 mindre ...