INDEX 



431 



Ether-particles, metaphysical, 395 



Ethics^ 419 



Evolution, the theory of, 37 

 *'~~~~- a slow process, 360 



based on prpbabilities,4Oi 

 nature of evidence for, 400 

 not a purposive process, 



373 



Evolution of life-forms, 318 

 External influence on organisms, 340 

 jExtjpction, of species, causes of, 



125-31 



FAKIR, sham death of the, 233 



Falcon, the, 98 



Feathers, origin of, 136 



Feeling in the mammal and the bird, 



Female choice, 81-7 

 Fertilisation of plants, 197-9 

 Fertility of animals, 26, 58 

 Fibula, the, 168 



Field-cricket, apparatus of the, 209 

 Field-mouse, the, 43 

 __ Final causes, 364 

 '"Fingers of the bird, 157 

 Fins, evolution of the, 154 

 Fishes, eggs of the, 59 

 Fitchet-weasel, the, 57 

 Flagellates, 292 

 Flea, the, 202, 270 

 Flesh-eating, beginning of, 238 

 Flight, instinct of, 66, 215 

 Flowers and insects, relation of, 197 

 Fluke, the, 282 

 Flying fish, the, 137 



squirrel, the, 137 

 Flying muscles of birds, 100 

 Food instincts, 66-8 

 Forestry and birds, 47 

 Formative energy in organisms, 344 

 Forms of living things, 352 

 Fossils, absence of early, 122-3 



,, formation of, 123 



,, scarcity of, 123-4 

 Fox, the, 23, 28 

 Free will, 423 



Freedom, sense of, in play and art, 73 

 Frog, the, 21 



adaptations in the, 145 

 Frog-spawn, 145 

 Fiindulus heteroclitus , 177 

 Fungi, 235, 238 



Future society, the Nietzschean 

 forecast, 419 



GALL-FLY, the 254 

 Galleries of ancestors, 402 



Game, injuries done by, 43 



Games, nature of, 60377 



Gatke, H., 79 



on speed of migration, 98, 

 101 



Genealogical trees, 359 



General concepts, 379 

 terms, use of, 392 



Generic names, 393 



Geology, evidence of, 35 



Geological succession of animals, 

 35-6 



Geometer-moth caterpillars, 193 



Germ-cells, 255, 297 



not Ideological, 366 

 ,, selection in the, 333 



Germ-plasm theory, the, 296 



Germinal selection, 333-40 



Ideological, 371 



Gill-clefts in the human embryo, 171 



Gills, evolution of the, 156 

 of snails, 244 



Good and bad, meaning of, 375 

 " Gordius aquaticus, 268 



Gourd-worm, the, 274, 283 



Graeser, Kurt, on migration, 105 



Grant Allen on heredity, 306 



Grasshopper, the, 137, 185, 187 



Groos, Professor, on animal play, 60 



Growth of insects, 186 



Glyptodont, the, 126-8 



HAECKEL, Professor, 399 

 Haemopis vorax, 268 

 Hairy coat, disappearance of, 342 

 Hamster, winter sleep of the, 56 

 Hare, the, 23, 28, 31 

 Harmful animals, 43 

 Harmonious adaptations, 207 

 Hawk-moth caterpillar, the, 188 

 Hawks, 43 



Hearing in the fish, 176-7 

 ^Hsajrt, the, 155 

 Heliconides, the, 194 

 Heligoland, migratory birds of, 98, 



102 



Henry II., falcon of, 98 

 Hereditary disease not to be spared, 



414 



^Heredity, 41, 256 

 law of, 118 

 nature of, 298 

 Hermaphrodism, 275 



in the plant, 199 



Hermit-crab, the, 225 

 Heron, the, 212 

 Hibernating animals, 55-7 

 Highest being, man as the, 424 



