Birds, xii, 239-69; anatomy of, 239, 247-8; appearance in eocene, xv, 71; care of young by, 275-6; carinate, xii, 250; colors of, 245-6; courtships of, xv, 274-5; embryological resemblances, 54; evolution, iii, 286, 295-7, xii, 195, 239-43; eyes of, xi, 98; fear in, 136; feathers of, xii, 243-7; flower fertilization by, xiii, 123; food of, ix, 24; game, xii, 261-3; heart of, x, 332; infectious diseases of, 206; luminous, i, 346-7; man's lessons from, xv, 206; migrations, cause, xiii, 55; monogamy of, xv, 276-7; oil-secreting organ of, x, 310; orders of, xii, 249; passerine, 268-9; phosphorus in excrement, xiv, 68; protective coloration in, xv, 17; ratite, xii, 243-49; ribs of, 184; seed dispersal by, xiii, 55, 58, 59, 340-3; sense of smell, xi, 78; singing of, iv, 209; singing organs, xii, 248-9; sleeping habits, xi, 287; teaching of young to fly, xv, 66, 275-6; temperature regulation in, ix, 306, 307, 308; used in hunting and fishing, xv, 223-4; various groups, xii, 264-7; warm-bloodedness of, ix, 305; water, xii, 250-9 Birds of Paradise, courtships of, xv, 275; plumes of, xii, 244 Birds of Prey, xii, 260-1 Birmingham Iron Region, iii, 358-9 Birs River, Jura Mountains, xiv, 94 Birth, ix, 344; body conditions and development at, 345-52; bones at, 58; freedom from germs at, x, 201; heart rate at, 334, ix, 347; muscle cells at, 48, 348; skull capacity at, xv, 40; temperature changes at, xi, 36-7; weight at, ix, 31 Births, male and female, ix, 340 Biscay, Bay of, depths, xiv, 289; sand destruction in, iii, 75 Bishop's Ring, i, 58, 183, 368 Bismarck, skull capacity, xv, 40 Bismuth, affinity strength, viii, 128; atomic weight and symbol, 383; expansion on solidifying, iv, 150; in Rose's fusible metal, 162; melting point, viii, 384; melting point, pressure effects on, iv, 163; occurrence, viii, 131; specific gravity, 384; tests for, 287-8 Bisons, xii, 329-30; formerly in Europe, xv, 76; pictured in Cro-Magnon art, 114-18 (fig.) Bitter, taste of, ix, 95, xi, 70, 71, 72 Bitterns, xii, 254-5 Bituminous Coal, beds in U.S., iii, 200-1, 346-7, 348; elements, 345; per cent carbon in, viii, (see also Soft Coal) Bituminous Strata, origin, iii, 249-50 Bivalves, xii, 58, 63 Black (color), absorption of light by, iv, 364, x, 309; produced by interference of lights, iv, 377-8; sensation of, ix, 115 Black, Joseph, chemical work, xvi, 119-20, 125, 177; discovery of respiration physiology, x, 88-9 Black Beetles, xii, 107 Blackberry, aggregate fruit, xiii, 55; in rose family, 197; origin, 224; running, 28 Blackbirds, xii, 269 Black Death, x, 163-4 "Black Earth," of Russia, xiv, 217 Blackfish, xii, 297