Activity, food needs dependent on, ix, 295, 296, 297; mind as, xi, 12, 13, 236; temperature effects on, i, 323-4 Activity (mechanics), iv, 80 Adaptations, of eardrum to sound, xi, 100; of eye to colors, 95; of nose to odors, 80-1; of skin to pressures, 111; of tongue to tastes, 72; to warmth and cold, 113 Adaptation to Environment, xv, 16; by animals, 16-18; by man, 3, 25, 26, 28, 31, 36; by plants, xiii, 11, 12, 28-31, 89-90, 149-50, 346, 355-83, xv, 16, 18-19; between insects & plants, xiii, 144, xvi, 152-3; mental efforts at, x, 361-2; natural selection and, xv, 24-5; principle never perfect, xvi, 152-3 (see also Environment, Environmental Variation) Adder's Tongue Fern, xiii, 159 Adding Machines, v, 326-7 Addison, Thomas, x, 106, 112 Adenoids, ix, 104, 224, x, 341-2; as infection foci, 220 Adenoid Tissue, ix, 223, 224 Ader, C., v, 231 Adiabatic Changes, iv, 158-9, 381 Adipose Tissues, ix, 298 Adirondack Mountains, age, iii, 191; club mosses in, xiii, 305; erratic bowlders in, iii, 70; fault blocks in, 89; fault lines and streams, xiv, 128; granite formation, iii, 112; Grenville strata, 165, 167; ice age survivals, xiii, 321; iron district, iii, 359; lakes, how formed, 145; lightning effects, 24; Ordovician strata eroded, iii, 186; quartz & slate formations, xvi, 29 Adjutant Bird, xii, 255 Admiration, sentiment of, xi, 146-7 Adolescence, mental conditions of, x, 236-7 Adrenalin, ix, 171-2, 209, 219, xi, 137, 138, 273 Adrenals, ix, 170-1; Addison's disease of, x, 112-13; functions, xi, 60, 137; shock effects, 59 Adriatic Sea, bora, i, 133; coasts of, xiv, 252-3, 263; filling in by deltas, 53; Karst district, 150 Adsorption, viii, 316, 373 Adulteration of Food, viii, 370-1 Adults, basal metabolism in, x, 271; growth in, ix, 287, 288-9; heart rate in, x, 334; protein needs of, ix, 281-3 Advance Metal, resistance, vi, 77 Advertising, psychology of, xi, 343-9; sign & display, vii, 339-43; tied images in, xi, 221; weather considerations, i, 255-6 Ægean Sea, volcanoes, xiv, 317, 319 Æolian Tones i, 195 Aerial Echoes, i, 190, 193 Aerial Roots, xiii, 20-2; of fig tree, (illus.), 48 Aerials, iv, 314, vii, 261; Dolbear's patent, xvi, 191; in aeroplane sets, vii, 282 (see also Antennæ) Aeroclinoscope, i, 282, 365 Aerology, i, 18-19, 20-3, 89, 365-6 Aeronautical Meteorology, i, 284-305