DARWIN, Mr., his principle of utility, 47; on cause of colour in flowers, 127, 262; on colours of caterpillars, 118; on sexual colouration, 260; his metaphors liable to misconception, 269; criticism of, in _North British Review_, 291. DESERT animals, colours of, 49, 50. DIADEMA, species of, mimic Danaidae, 86, 87; female with male colouration, 112. _Diadema misippus_, 112; _D. anomala_, 113. _Diaphora mendica_, 89. DICNYODONTIA, 299. DICROURUS, 253. _Diloba coeruleocephala_, 120. DIMORPHISM, 145; in beetles, 155; in birds, 155; illustrated, 157. DINOSAURIA, 298. DIPTERA mimicking wasps and bees, 97. _Doliops curculionides_, 94. DOMESTICATED animals, their essential difference from wild ones, 38-41. DOTTERELL, 251. DRUSILLA, mimicked by three genera, 181. _Drusilla bioculata_, 180. DYTISCUS, dimorphism in, 155. EGYPTIAN architecture, introduced, 225. _Elaps fulvius_, _E. corallinus_, _E. lemniscatus_, 101; _E. mipartitus_, _E. lemniscatus_, _E. hemiprichii_, 102. ENODES, 196. ENNOMUS, autumnal colours of this genus, 62. _Eos fuscata_, dimorphism of, 155. EQUUS, 299. _Eronia tritaea_, 172; _valeria_, 172. _Eroschema poweri_, 93. ERYCINIDAE mimic Heliconidae, 84. _Erythroplatis corallifer_, 92. ESTRELDA, sexual colouring and nidification of, 243. EUCNEMIDAE, mimicking a Malacoderm, 93. _Eudromias morinellus_, 251. _Euglossa dimidiata_, 98. EUMORPHIDAE, a protected group 72; imitated by Longicorns, 92. EUPLOEA, local modifications of colour in, 173. _Euploea midamus_, 87-113, 179; _E. rhadamanthus_, 87, 179. _Eurhinia megalonice_, 172; _polynice_, 172. EURYLAEMIDAE, sexual colouring and nidification of, 243. EXTINCT animals, intermediate forms of, 298. EXTINCTION of lower races, 318. FEMALE birds, colours of, 114; sometimes connected with their mode of nidification, 240; more exposed to enemies than the males, 248. FEMALE butterflies generally dull-coloured, 259. FEMALE insects, mimicry by, 110, 259; colours of, 113. FEMALE sex, has no incapacity for as brilliant colouration as the male, 247; in some groups requires more protection than the male, 258. FISHES, protective colouring of, 55. FISSIROSTRAL birds, nests of, 238. FLOWERS, causes of colour in, 127. FLYCATCHERS, genera of, absent from Celebes, 177. FORBES, EDWARD, objections to his theory of Polarity, 17-23. FORCE is probably all Will-force, 366. GALAPAGOS, 10. GALTON, Mr., on range of intellectual power, 339. GANOCEPHALA, 298. _Gastropacha querci_, protective colour and form of, 62. GAUDRY, M., on fossil mammals of Greece, 299. GEOGRAPHICAL distribution, dependent on geologic changes, 1; its agreement with law of introduction of new species, 9; of allied species and groups, 12.