Imagery, 214, 215, 218, 219, 220, 221, 228, 229, 241, 243; a function of the living cerebral cortex, 221; association of, 241; cerebral, 218; concrete, 220, 221; different in different persons, 219; distributed by abnormal state of cortex, 221; motor, 214; neurographic, 243; represents only superficial and exterior properties, 219; rigid, correlated with metabolic process at work in cerebral cortex, 228, 229; rigidly proportioned underlying neurogram, 215; sensible, presupposed by thought and volition, 221; shows corresponding degrees of integrity and intensity, 229; sporadic and fragmentary, 229; tactile, 214 Imagination, 213, 221, 222, 228, 229, 231; cerebral sense, 222, 228, 229; its normal exercise depends on physiological normality of cerebral cortex, 221; organic function, 231 Imaginative activity, 229 Immortality, considered an anodyne, 358 Immunity, 57 Immutibility, 50, 52 Impenetrability, 225; of matter, law of, 225; reflection opposed to, 225 Improvised structures, 281 _note_, 283 Incubation, purposeless, 259 Independent Assortment, Law of, 27 Index fossils, 93, 94, 96, 97, 100, 104, 107, 108, 109, 110, 111, 112, 335, 339; basis of stratigraphic correlation, 93, 94; an arbitrary and elastic criterion, 94, 95; final court of appeal, 93, 96, 97, 335; in conflict with physical and stratigraphic evidence, 100, 104-112 India, 114 Indian dialects, work of philosophers, 338 Indian Ocean, 114, 115 Individuation, 220, 224; concrete, 224 Indo-Europeans, 334 Industry, Mousterian, 326, 327, 329, 330, 331; Acheulean, 331; Aurignacian, 331 Inertia, defined, 174 Infusion, 193; not supernatural, 193; of spirit into matter, not a miracle, 193 Infantilism, 294 Inference, 221, 240; mediate, 221 Infundibulum, 293 Infusoria, supposed abiogenetic origin of, 134 Inheritance, 2, 8, 9, 24, 27, 38, 40, 41, 42, 45, 56, 57, 62, 63, 64, 75, 160, 294, 320; definition of, 41; biparental, 160; chemical theory of, 57; laws of, 2, 24, 27, 42; similifying process, 40, 45 —not only one, 56 —also said to diversify, 63, 64; variable, 75 Inhibition, 242, 252 Initial vivification, 133; act, 133; of matter required a formative, 133; rather than creative, 133 Inquilines, 46 Insectivora, 275 Insects, 225, 307; evolutionary diminuendo of, 116; wingless, 307