Natural history History 331 Description and travel 277 Travel 134 Ecology 92 Pre-Linnean works 90 Nature in literature 83 more ... Science 74 Naturalists 70 Environmental conditions 61 Nature 54 Social life and customs 53 Human ecology 49 Knowledge and learning 48 History and criticism 47 Sciences naturelles 45 Biology 42 Zoology 40 Discovery and exploration 35 Geology 34 natural sciences 34 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 less ...