Dakota Sandstone Formation, iii, 114, 115 (fig.) Dalmatia, coast of, xiv, 252, 257; harbors of, 268 Dalton, John, xi, 93, xvi, 133, 160, 162 Daltonism, inheritance of, ix, 340 Damaraland, desert plant of, xiii, 380 Damascus, swords of, v, 315 Damped Waves, vii, 264, 273, 286-8, 290 Dampier, William, i, 130, xvi, 114 Damping, in meters, vii, 159 Dams, beaver, xii, 295-6; use of, v, 76, vi, 361, 364 Damsel Flies, xii, 105 Dances, Indian, xv, 305-6; primitive, 310-12, 313, 316 Dandelion, family of, xiii, 206; flower of, 49; origin, 223, 353-4; roots, 16; seed dispersal, 58-9, 344 Daniell Cell, viii, 167 Dante, skull capacity, xv, 40 Danube River, delta of, xiv, 185; historical importance, xv, 138-9; longitudinal character, xiv, 154; varied course, 155 Danzig, Poland and, xiv, 306 Darby, Abraham, v, 316 Dardanelles, important to Russia, xiv, 267 Dardanelles Expedition, i, 308 Dark Days, i, 56-7, ii, 211 Darkness, distinguishing of, by primitive animals, ix, 105; effect on plants, xiii, 72, 76, 77, 84-90; effects on plants, animals, and man, x, 253; from interferences of light, iv, 377-8; horrors of world of, 51; periodic seeking of, xi, 52-3; sleep and, 282, 288; tuberculosis germ and, x, 290, 291 Dark Segments, i, 167, 371 Darning Needles (flies), xii, 105 Darwin, Charles Robert, x, 134-6, xv, 15; book on fertilization of orchids, xiii, 145; book on restless plants, 110; epigenesis theory, xvi, 118; experiment on destruction of seedlings, xv, 21; experiment with tendrils, xiii, 112; naturalist on "Beagle," 224, x, 134-5, xvi, 142; on descent of man, xv, 56; on emotions, xi, 131-3; on expression of emotions by animals, xv, 64-5; on fossil record, xiii, 302; on Madagascar orchid, 48; on self-fertilization, 135; on sexual selection, xv, 274; on variations, 334; "Origin of Species," x, 135, xiii, 334, xvi, 148, 167, 181-2; skull capacity, xv, 40 (see also Darwinian Theory) Darwin, Erasmus, x, 134, xvi, 148 Darwin, George H., tidal friction theory, ii, 375-6, 377, 156-7 Darwinian Theory, x, 135, 136, xv, 15, 24-5, 56, xvi, 149-51, 152; Bagehot on changes wrought by, xvi, 198; Greek anticipation of, 79; horror first caused by, xv, 53; naturalism and, xvi, 111; philosophical effects of, 195 Dassies, South African, xii, 304 Dasyures, xii, 278 Date Palm Tree, xv, 125 David's Deer, xii, 316 Davos, health resort, i, 210, 325 Davy, Edmund, xvi, 190 Davy, Sir Humphry, electrical work, vi, 16, 19, xvi, 122, 189; heat studies, iv, 43, xvi, 131; laughing gas discovery, x, 123-4, 125 Day, divisions of, v, 57, xvi, 57; mean solar, iv, 15-16; periods of high and low temperatures, i, 76, xiv, 347-8; periods of highest energy, xi, 277 Day and Night Breezes, i, 131 Dayflies, xii, 104