Geography, changes since prehistoric times, xiv, 29-30; civilization and, xv, 122-3, 128-39; defined, iii, 9-10, 379, xvi, 36; development of science of, 94, 98, 114, 123-4; genetic conception of, xiv, 3-4; history and, 10, 30-1, 191-7, 239-45, 249-50, 261-2, 279-82, 305-11 Geological Ages, iii, 19-21, xv, 71; determined by fossils, iii, 15, 18-19; estimate of lengths, xiii, 314, 322; length seen in coal formations, iii, 201; length seen in chalk deposits, 218; length shown by mosses, xiii, 306 GEOLOGY, Volume iii Geology, daily interest, xvi, 22-5; definition and scope, iii, 3, 9, 11, 12, 378, xvi, 37; history of development, 126, 168-73; mineralogy and, iii, 309 Geometry, of Greeks and Hindus, xi, 239-40; history of, xvi, 54, 68, 81, 89, 90 George, Lake, iii, 145; stream changes around, 243 Georgia, aluminum production, iii, 369; cotton of, xiii, 237; glacial period in, xiv, 376; soil of, 218 Georgian Planet, ii, 267 Geotropism, xiii, 85 Geranium Family, xiii, 200 Geraniums, fertilization, xiii, 136; killed by hot water, 299; multiples of five in, 176; turning to light, 85; petal arrangement, 190 Germanium, discovery, viii, 180; symbol and atomic weight, 383 Germans, in Alpine group, xvi, 49; grouped as Huns, xi, 22 German Silver, copper alloy, viii, 164; resistance, vi, 76, 77 Germany, aeronautical weather service, i, 304; barley growing in, xiv, 365; beet sugar production, xiii, 216; coal deposits, iii, 345; coasts of, xiv, 247; early surgery, xvi, 181; earthquakes of, xiv, 128; forest policy, xiii, 372, xiv, 238-9, 382; geological works, xvi, 170; hail insurance, i, 344; in World War (see World War); loess deposits, xiv, 72; medicine of, Muller's influence, x, 118; meteorological establishments, i, 222-3; meteorology in World War, 309, 310; military aviation development, 40; mining products, iii, 362, 364; moor fires in old, i, 56; mountains of, xiv, 96, 235; nitrogen fixation in, i, 36-7, xiv, 66; plains of, 217; potash deposits, viii, 130, 143, 144, 344, xiv, 67-8, 209; salt beds of north, iii, 204, xiv, 141; "sheep-cold", i, 363; topography of western, xiv, 87 (map), 90; unke toad of, xii, 176 Germ Cells, ix, 324-5, 327, 332, 339, x, 232, xvi, 156, 157-8; in reproduction, x, 233; source of, xii, 27 (see also Germinal Tissue, Germ Plasm) Germinal Tissue, ix, 324-5; chromosomes of, 328, 329, 339; development of germ cells in, 332, 339; heredity dependent on, 325-8; independence of, 325 (see also Germ Plasm) Germination of Seed, after low temperatures, i, 32; acacia plant of Natal, xiii, 375; ancient wheat grains, 211, ix, 16-17; bird-carried seed, xiii, 340, 341; seed in sea water, 346, 348