By Darwin, Charles, 1809-1882 / Gray, Asa, 1810-1888 . Genre Variation (Biology) / Domestic animals / Plants, Cultivated . Names plants / rock / flowers / fruit / animals and 4099 more

By Japp, Alexander H. (Alexander Hay), 1839-1905 / Darwin, Charles, 1809-1882 / Romanes, George John, 1848-1894 . Genre Cuckoos / Birds / Behavior / Coucous / Oiseaux and 1 more . Names life / american / idea / insects / called and 783 more

By Darwin, Charles, 1809-1882 . Genre Oligochaeta / Humus / Soil formation . Names leaves / stones / soil / grass / animals and 952 more

By Darwin, Charles, 1809-1882 . Genre Evolution / Natural selection / Heredity / Human beings / Origin and 1 more . Names animals / life / insects / animal / order and 2338 more

By Romanes, George John, 1848-1894 / Darwin, Charles, 1809-1882 . Genre Animal intelligence / Instinct / Psychology, Comparative . Names animals / animal / life / insects / order and 2548 more

By Poulton, Edward Bagnall, Sir, 1856-1943 / Darwin, Charles, 1809-1882 . Genre Darwin, Charles1809-1882 / Natural selection . Names life / animals / plants / none / animal and 645 more

By Poulton, Edward Bagnall, 1856- / Darwin, Charles, 1809-1882 . Genre Darwin, Charles1809-1882 / Natural selection . Names life / animals / plants / none / animal and 867 more