Indian Corn, American origin, xiv, 382; history and uses, xiii, 211-13; prop roots, 20 (fig.); stem, 183 (see also Corn) Indian Meteorological Dept., i, 241 Indian Ocean, extent of, xiv, 22; monsoons of, 350-1; salt in, viii, 139; sharks of, xii, 146; tortoises on islands of, 192 Indian Pipe Plant, xiii, 99, 202 Indians, American, acuteness of vision, vi, 272-3; arrows of, xv, 196 (fig.); basket-weaving of, 248; bows of, 214 (fig.); canoe-making, 262; cattle-raising stage absent, 187, 199; chiefs, 364; color of, 37; corn-growing, xiii, 211-12, 212-13, xv, 201 (fig.); dogs used in hunting, 223; domestic animals lacking to, 199; dramatic ceremonies and plays of, 305-6, 306-7, 308; fear of pogonip, i, 96; fertilizing method of, xv, 202; guardian spirits, 348-9; hair of, 37; Happy Hunting Grounds of, 333; "hiqua" money of, xii, 74; language deficiencies, xv, 144; lodgepoles of, xiv, 374; long houses of, xv, 267; marriage practices, 283-4, 284; measles and, 48; mineral springs used by, xiv, 145; note to Jenner, x, 103; painting of faces by, xv, 256; pottery of, 250 (fig.), 252 (fig.); prairie firing, xiii, 374; prayers of, xv, 346-7; religious beliefs, xvi, 44; signal fires, xv, 165-6; sign language, 148-51; sign writing, 172, 173 (fig.); stone pestles of, 238 (fig.); tents of, 266; tomahawks of, 208; tree-felling by, 262; tribal morality of, 374; tribes in mountains, 129-30; unions among, 363; weaving of, 247 (fig.), 301 (fig.) (see also South American Indians) Indian Summer, i, 361-2, 363, 375 India-rubber, elasticity of, iv, 36; low temperature effects, i, 31 Indicators, chemical, viii, 114, 294, 378 Indigestion, causes and results, ix, 238-42; from worry, 165, 167; mental effects, xi, 369-70 Indigo (color), ix, 115; changed to indigo white, viii, 259 Indirect Lighting, vi, 277, vii, 70 Indium, symbol and atomic weight, viii, 383 Individuals, differences in, ix, 327, xi, 152-9; influence of, in history, 333; inheritance of extreme characters, xvi, 154; moral control, 48; new species from variations of, xiii, 325, 328-9; psychology in crowds, xi, 324, 325-30; transmission of acquired characters, ix, 325-6 Indo-China, food plant source, xiii, 221; python of, xii, 214 Indo-Chinese, in yellow race, xv, 37 Indo-European Languages, xv, 161, 162 Induced Currents, iv, 303-9 Induced Voltages, vii, 370 Inductance, defined, vi, 91, 166; in direct and alternating currents, 166-7, 169; flashes caused by, 102, 312; in induction motors, 248; in telephone lines, vii, 104; in wireless communication, 264, 286-7, 289, 293-5, 296-7 Inductance Coils, vii, 105, 264, 266, 267