Absolute perfection. See Perfection, absolute. 

Abyssinia, plants of, 375 

Acclimatisation, 139 

Accumulation (of small changes), 32 

Acquired characters, 15, 209 

Adaptation, 139, 141, 169; special, 440; of forms, 469 

Adaptive perfection, 186 

Adult: as advanced stage, 449; modifications in, 86 

Affinities of extinct species, 329; of organic beings, 411 

Agassiz on amblyopsis, 139; on groups of species suddenly appearing, 302, 305; 
embryological succession, 338; on the glacial period, 366; on embryological 
characters, 418; on the embryos of vertebrata, 439; on parallelism of embryoloical development and geological succession, 449 

Albinism, 13, 275 

Algae of New Zealand, 376 

Alligators, males, fighting, 88 

Arnblyopsis, blind fish, 139 

America, North, productions allied to those of Europe, 371; boulders and glaciers of, 373; South, no modern formations on west coast, 290

Ammonites, sudden extinction of, 321 

Anagallis, sterility of, 247 

Anagenesis, 420 

Analogy of variations, 159 

Ancestor, common, 280, 351 

Ancon sheep. See Sheep, ancon. 

Ancylus, 386 

Animals, not domesticated from being variable, 17; domestic, descended from several stocks, 19; of Australia, 116; with thicker fur in cold climates, 133; blind in caves, 137; acclimatisation of, 141; lower, 338, see also Nature, scale of; extinct, of Australia, 339 

Animals and plants, difference, 48 

Anomma, 240 

Antarctic islands, ancient flora of, 399 

Anti-creation argument, 390, 394, 398, see also Creation. 

Antirrhinum, 161 

Ants: attending aphides, 209-211; slave-making instinct, 219; neuter, structure of, 236; division of labor, 242 

Aphides attended by ants, 211 

Aphis, development of, 442 

Apteryx, 182 

Arab horses, 35 

Aralo-Caspian Sea, 339 

Archetype, 435 

Archiac, M. de, on the succession of species, 325 

Artichoke, Jerusalem, 142

Ascension, plants of, 389 

Asclepias, pollen of, l93 

Asparagus, 359 

Aspicarpa, 417 

Asses, striped, 163 

Ateuchus, 135 

Audubon on habits of frigate-bird, 185; on variation in birds'-nests, 212; on heron eating seeds, 387 

Australia, animals of, 116; dogs of, 215; extinct animals of, 339; European plants in, 375 

Azara on flied destroying cattle, 72 

Azores, flora of, 363

Bakewell, Mr., 35, 36 

Balancement of growth, 147 

Bamboo with hooks, l97 

Barberry, flowers of, 98 

Barnacles (from Cuvier), 440 

Barrande, M., on Silurian colonies, 307, 313; catastropic belief of, 317; on the succession of species, 325; on parallelism of palaeozoic formations, 328; on affinities of ancient species, 330 

Barriers, importance of, 347 

Batrachians on islands, 393 

Bats, now structure acquired, 180; distribution of, 394, 404 

Beagle, H. M. S., 1, 386 

Bear, catching water-insects, 184 

Bees, queen (killing rivals), 202; sting of, 202, also see Humble-bee, and Hive-bee. Bees, fertilising flowers, 73 

Bees, hive, not sucking the red clover, 95; cell-making instinct, 224; humble, cells of, 225; parasitic, 218

Beetles, wingless, in Madeira, 135; with deficient tarsi, 135

Behavior. See Instinct. 

Bentham, Mr., on British plants, 48; on classification, 419 

Berkeley, Mr., on seeds in salt-water, 358 

Bermuda, birds of, 391

Biographic generalizations, 346 

Birch, Mr., on pigeons, 27 

Birds, song of males, 89; colour of, on continents, 132; wingless, 134, 182; acquiring fear, 212; fossil, in caves of Brazil, 339; transporting seeds, 361; annually cross the Atlantic, 364; waders, 386; of Madeira, Bermuda, and Galapagos, 390; with traces of embryonic teeth, 451 

Bizcacha, 349; affinities of, 429 

Bladder for swimming in fish, 190 

Blindness of cave animals, 137 

Blyth, Mr., on distinctness of Indian cattle, 18; on striped Hemionus, 163; on crossed geese, 253 

Boar; shoulder-pad of, 88 

Borrow, Mr., on the Spanish pointer, 35 

Bory St . Vincent on Batrachians, 393 

Bosquet, M., on fossil Chthamalus, 304 

Boulders, erratic, on the Azores, 363 

Branchiae, 190 

Branching, 317 

Breeders, reference to, 11, 29, 30, 31, 112, 443 

Brent, Mr., on house-tumblers, 214; on hawks killing pigeons, 362 

Brewer, Dr., on American cuckoo, 217 

Britain, mammals of, 395 

Bronn, on duration of specific forms, 293, 312 

Brown, Robert, on classification, 414, 416

Buch, L. v, 301

Buckland, Mr., on fossils, 329

Buckley, Mr., Leichester sheep, 36

Buckman on variation in plants, 10

Bumble-bees. See Humble-bees.

Burgess, Mr., Leichester sheep, 36

Buzareingues on sterility of varieties, 270

Calceolaria, 251 

Canary-birds, sterility of hybrids, 252 

Cape de Verde Archipelagos, 398, 478 

Cape of Good Hope, plants of, 110, 375 

Carrier-pigeons killed by hawks, 362 

Cassini on flowers of compositae, 145 

Catasetum, 424 

Catastrophes, 317, 487 

Cats, with blue eyes, deaf, 12; variation in habits of, 91; curling tail when going to spring, 201

Cattle destroying fir-trees, 71; destroyed by flies in La Plata, 72; breeds of, locally extinct, 111; fertility of Indian and European breeds, 254 

Cautley, Mr., on discoveries in India, 340 

Cave, inhabitants of, blind, 137 

Centers of creation, 352 

Cephalopodae, development of, 442 

Cervulus, 253 

Cetacea, teeth and hair, 144 

Ceylon, plants of, 375 

Chalk formation, 322 

Chance variation, 131, also see Variation. 

Changes, monogenetic versus genetic, 11; climatic, 353; geographical, 353 

Characters, 45, 103, 154-155, 162, 413-414, 417-418, 425-426; divergence, 111, 127-128; specific, 154, 156, 168; generic, 155-156, 168; sexual, 156; slight, l94-195; acquired, 209; functional significance, 415; correlated, 418; adaptive or analogical, 427

Charlock, 76

Checks to increase, 67; mutual, 71

Chickens, instinctive tameness of, 216

Chthamalinae, 288

Chthamalus, cretacean species of, 304

Circumstances favourable to selection of domestic products, 40; to natural selection, 101

Cirripedes capable of crossing, 101; carapace aborted, 148; their ovigerous frena, l92; fossil, 304; larvae of, 440

Cladogenesis, 420

Classification: genetic criterion, 16, 154-155, 413, 419; natural system, 329, 411, 413, 415, 417, 420, 425, 426, 431, 456, 486; Darwin's system, 425

Clift, Mr., on the succession of types, 339

Climate, 17, 69, 132-133, 141; effects of, in checking increase of beings, 68, 353; and fur, 133; adaptation of, to organisms, 139

Co-adaptations, 61, 132; disorganization of, 266

Cobites, intestine of, 190

Cockroach, 76

Coexistence, 52

Collectioils, palaeontological, poor, 287

Collins, Mr., 35

"Colonies," of M. Barrande, 313

Colour, influenced by climate, 132; in relation to attacks by flies, 198

Columba livia, parent of domestic pigeons, 23

Colymbetes, 386

Common ancestor, 280, 35; reconstruction of, 436

Common progenitor. See Progenitor, common.

Compensation of growth, 147, 455

Competition, 62, 68, 69, 75-78, 106, 110, 121, 139-140, 172, 175, 205-206, 281, 314, 320, 337, 351, 402, 408, 412, 429, 472; experiment on, 68; as cause of extinction, 109; reduced, 139; among close relatives, 402

Compositae, outer and inner florets of, 144; male flowers of, 451

Conclusion, general, 480

Conditions, slight changes in, favourable to fertility, 267; of existence, see Existence, conditions of .

Convergence, 193-194, 427, 430

Coot, 185

Coral-islands, reefs, indicating movements of earth, 309; seeds drifted to, 360

Corn-crake, 185

Correlated characters, 418

Correlated effects, 143, 144, 146, 147, 150, 159, 168, 265

Correlation of growth in domestic productions, 11; of growth, 33, 143, 198, 466

Cowslip, 49

Creation, act of, 315, 437, 469, 483, 487

"Creation, plan of, " 482, 486 

"Creation, single centers of," 352, 356

Creation, theory of independent (reference to), 355, 393-394, 456, 472, 474, 478

Creator, the, reference to, 186, 188-18g, 413, 435, 488

Crinum, 250

Crosses, first, of hybrids, 255, 272, 276-277; reciprocal, 258

Crossing, 257; of domestic animals, importance in altering breeds, 20; advantages of, 96; unfavourable to selection, 102

Crustacea of New Zealand, 376

Crustacean, blind, 137

Cryptocerus, 238

Ctenomys, blind, 137

Cuckoo, instinct of, 216

Currants, grafts of, 262

Currents of sea, rate of, 359

Cuvier on conditions of extistence, 206; on fossil monkeys, 303; on ranking of Ruminants and Pachyderms, 329; on barnacles, 440; Fred., on instinct, 208

Darwin: as experimentor, 67, 97, 99, 142, 228, 358, 361, 386, 445; as ecologist, 68, 73; as anticreationist, 95, 129, 135, 167, 352, 355, 390, 394, 396, 398, 411-458, 473, 478; as writer, 130, 310-311, 489-490; as antisoltationist, l94

Dawson, Mr., on carboniferous beds, 296

De Beaumont, Elie, catastrophist, 317

De Candolle on struggle for existence, 62; on umbelliferae, 146; on general affinities, 430

De Candolle, Alph., on widely-ranging plants being variable, 53; on naturalisation, 115; on winged seeds, 146; on Alpine species suddenly becoming rare, 175; on distribution of plants with large seeds, 360; on vegetation of Australia, 379; on fresh-water plants, 386-387; on insular plants, 389; on distinct species, 402; on low plants, widely dispersed, 406; transportation of seeds, 406

Degradation of coast-rocks, 282

Denudation, rate of, 285; of oldest rocks, 308

Descent: diagrom of, 117; with modification, 123, 340, 430-431, 433, 456; unity of, 206; principle of, 331, 333, 336, 426, 475; community of, 425, 426, 449; in classification, 425; assumption of, 433; as key to natural system, 449; from common parent, 458

"Design, unity of, " 482 

Development of ancient forms, 336 

Deviation of structure, 132 

Devonian systern, 334 

Dianthus, fertility of crosses, 256 

Differences. See Variation. 

Differences, innate, 143

Differentiation, 169 

Diffusion, process of, 326 

Dirt on feet of birds, 362 

Discontinuities, 27g; distributional, 353 

Dispersal: gene flow, 102, 356; migration, 293, 350, 35i, 353, 356, 365, 388, 396, 408; land bridges, 356; means of 356, 360; islands as stepping stones, 357; experimental, 358, 362, during glacial period, 365

Distribution, geographical, 314, 346, 408, 419, 427, 461, 476; means of, 356

Distribution of organic beings. See Organic beings, distribution of.

Disuse, 11, 135, 138, 168, 182, 216, 454-455, 479-480; effects of, under nature, 134

Disuse and Use, combined reference. See Use and Disuse.

Divergence of character, 53, 57, 111, 116, 127-128, 129, 332, 433

Divergence, principle of, 112, 331; among specially adopted larvae, 440

Divergent forms, 303

Diversification (of regional plants) advantage of, 115, 116 

Division, physiological, of labour, 115 

Dogs, hairless, with imperfect teeth, 12; descended from several wild stocks, 18; domestic instincts of, 213; inherited civilisation of, 215; fertility of breeds together, 254; fertility of crosses, 268; proportions of, when young, 444 

Domestication, 212-213, 253-254, 467; variation under, 7 

Domestic instinct. See Instinct, domestic. 

Dominant groups, 428 

D'Orbigny, Mr., conchologist, 297 

Downing, Mr., on fruit-trees in America, 85 

Downs, North and South, 285 

Dragon-flied, intestines of, 190 

Drift-timber, 360 

Driver-ant, 240 

Drones killed by other bees, 202 

Duck, domestic, wings of, reduced, 11; logger-headed, 182 

Duckweed, 385 

Dugong, affinities of, 414 

Dung-beetles with deficient tarsi, 135 

Dyticus, 386

Ears, drooping, in domestic animals, 11; rudimentary, 454 

Earth, seeds in roots of trees, 361 

Eciton, 238 

Economy of nature. See Nature, economy of. 

Economy of organisation, 147; principle of, 455 

Ecotypes, 132 

Edentata, teeth and hair, 144; fossil species of, 339 

Edwards, Milne, on physiological divisions of labour, 115; on gradations of structure, 194; on embryological characters, 418; on group types, 433 

Edwards, Mr. W. W., 164 

Eggs, young birds escaping from, 87 

Electric organs. See Organs, electric. 

Elephant, rate of increase, 64; of glacial period, 141 

Elliot, Hon. W., 20 Embryology, 439 

Embryonic structure, 449 

Embryos (embryology, larvae), 86, 338, 424, 439-442, 449, 457; conditions of existence, 339-340; resemblance, 439-440; change in organization, 441; less modified state of being, 449; picture of common parent for 450 

Environment. See Lamarck. 

Europe during later tertiary, 371 

Evolution: domestic, 30; favorable conditions, 107; evidence for, 128; slow, 199, 336; rate of, 313, 314, 316; faunal, 324; randomness, 334; progressive, 336-367; proof of, 411-458, 469-470; of parts, 437; gradual, 460

Evolutionary divergence, 260-261

Evolutionary inertia, l99, 331-332

Existence, conditions of, 206

Existence, struggle for. See Struggle for existence.

Extinction, l09 116, 127, 129, 203, 317-318, 320, 332, 433; as bearing on natural selection, 109; of domestic varieties, 111

Eye, example of adaptive perfection, 186, 187; structure of, 187; correction for aberration, 202

Eyes reduced in moles, 137

Eyton, Mr., on hybrids, 253

Falcone, Dr.,naturalisation of plants in India, 65; on fossil crocodile, 313; on elephants and mastodons, 334; and Cautley on mammals of sub-Himalayan beds, 340; on tropical heat, 378

Falkland Island, wolf of, 393

Family tree, 117, 129

Faults, 285

Faunas, rates of evolution, 324; succession of, 327; production of, 346; marine, 348; relationship of, 398, 403, 478; of oceanic islands, 403

Favoured individuals, preservation of, 467

Fear, instinctive, in birds, 212

Feet of birds, young molluses adhering to, 385

Fertility of hybrids, 249; from slight changes in conditions, 267; of crossed varieties, 267

Final causes, doctrine of, 435

First crosses of hybrids. See Crosses, first.

Fir-trees destroyed by cattle, 71; pollen of, 203

Fish, flying, 182; teleostean, sudden appearance of 305; eating seeds, 362, 387; fresh-water, distribution of, 384

Fishes, ganoid, now confined to fresh water, 107; electric organs of, l92; ganoid, living in fresh water, 321; of southern hemisphere, 376

Flight, powers of, how acquired, 182

Flora: of oceanic islands, 403; production of, 346

Flowers, structure of, in relation to crossing, 97; of compositae and umbelliferae, 144

Food, chains, 72; effects of, 85

Forbes, E ., on colours of shells, 132; on abrupt range of shells in depth, 175; on poorness of palaeontological collections, 287, 291-292; on Silurian stratum, 307; on continuous succession of genera, 316; on continental extensions, 357-358, 389; on distribution during glacial period, 366; on parallelism in time and space, 409

Forests, changes in, in America, 74

Formation, Devonian, 334

Formation, fossiliferous, 295, 300, 315, 327, 465, 487

Fomations, thickness of, in Britain, 284, intermittent, 290

Formica rufescens, 219; sanguinea, 219; flava, neuter of, 239

Fossiliferous formations. See Formation, fossiliferous.

Fossils (reference to), 130, 179, 183, 187, 291, 297-298, 333, 335-336, 341, 463, 475, 483

Frena, ovigerous, of cirripedes, 192

Fresh-water productions, dispersal of, 383

Fries on species in large genera being closely allied to other species, 57

Frigate-bird, 185

Frogs on islands, 393

Fruit-trees, gradual improvement of, 37; in United 
States, 85; varieties of, acclimatised in United States, 142 

Fuci, crossed, 258 

Function, change in, 454 

Fur, thicker in cold climates, 133 

Furze, 439

Galeopithecus, 181 

Game, increase of, checked by vermin, 68 

Gärtner, Mr. K. F., on crossing plants, 50; on pollen, 98; on sterility of hybrids, 246-247, 248, 249, 255; on reciprocal crosses, 257-258; on innate differences, 262; On blue and red pinpernel, 268; on crossed maize and verbascum, 270; on comparison of hybrids and mongrels, 272-273 

Geese, fertility when crossed, 253; upland, 185 

Genealogy important in classification, 425 

Genera, 59; distinct, 61 

Generations, 424 

Generative variability. See Variability, generative. 

Generic characters. See Characters, generic and Inheritance. 

Genesis, Book of, 34 

Genotypes, 159 

Geoffroy, St. Hilaire, 8, 11, 144 on balancement, 147; on homologous organs, 434; 

Geoffroy, Isidore, on correlation in monstrosities, 11; on correlation, 144; on variability of repeated parts, 149; on variable parts being often monstrous, 155 

Geographic, variation, 132 

Geographical distribution. See Distribution, geographical. 

Geographical races. See Races, geographical. 

Geography, ancient, 487

Geological record, imperfection of, 172, 279-280, 292, 341, 450, 464; time, 282

Geology, imperfection of the record, 279; future progress of, 487

Giraffe, tail of, 195

Glacial period, 365; dispersal during, 365

Gmelin on distribution, 365

Gnathodon, fossil, 368

God, 167; also see Creator and Creation.

Godwin-Austen, Mr., on the Malay Archipelago, 299

Goethe on compensation of growth, 147

Gooseberry, grafts of, 262

Gould, Dr. A., on land-shells, 397

Gould, Mr., on colours of birds, 132, 133 on birds of the Galapagos, 398, on distribution of genera of birds, 404

Gourds, crossed, 270

Gradation, morphological, 181-182; principle of 225, 474

Grafts, 10; 261, capacity of 261

Grasses, varieties of, 113

Gray, Dr. Asa, on trees of United States, 100; on naturalised plants in the United States, 115; on rarity of intermediate varieties, 176; on Alpine plants, 365; on identical species, 372

Gray, Dr. J. E., 163; on striped mule, 165; on maternal love of European cuckoo, 218

Grebe, 185

Grouping, not an artifact of extinction, 432; due to extinction, 489

Groups, arrangement of, 420; dominant, 428; aberrant, 429

Grouse, red, a doubtful species, 49; colours of, 84

Growth, correlation of, in domestic products, 11; correlation of, 143; compensation of, 147

Growth rings, in trees, 72

Hair and teeth, correlated, 144 

Harcourt, Mr. E. V., on the birds of Madeira, 391 

Hartung, M., on boulders in the Azores, 363 

Hazel-nuts, 359 Hearne on habits of bears, 184 

Heath, changes in vegetation, 72 

Heer, 0., on plants of Madeira, 107 

Helix pomatia, 397 

Helosciadium, 359 

Hemionus, striped, 163 

Herbert, W., on struggle for existence, 62; on sterility of hybrids, 249 

Herbert, Rev. W., on hybrids, 250-251 

Hermaphrodites crossing, 96 

Heron eating seed, 387 

Heron, Sir R., on peacocks, 89 

Heusinger on white animals not poisoned by certain plants, 12 

Hewitt, Mr., on sterility of first crosses, 264 

Higher catagories, origin, 123, 128, 171, 183, 186, 192, 194, 332, 338; change in function, 190-191; restriction of function, 190; arbitariness of, 419

Himalaya, glaciers of, 373; plants of, 375

Hippeastrum, 250 

Hive-bee, reference to, 94, 207, 209, 224, 227, 233-235 

Holly-trees, sexes of, 93 

Hollyhock, varieties of, crossed, 271 

Homeostasis, 150 

Homologous parts, 143 

Homology, 168; serial, 149, 436, 438 

Hooker, Dr ., 2, 3; on species and varieties, 53; on trees of New Zealand, 100; on acclimatisation of 

Himalayan trees, 140; on flowers of umbelliferae, 145; on glaciers of Himalaya, 373; on plants of Tierra del Fuego, 374, 378; on Australian plants, 375, 399; on algae of New Zealand, 376; on vegetation at the base of the Himalaya, 378; on relations of flora of South America, 379; on flora of the Antarctic lands, 381, 399; on Nelumbium luteum, 387; on the plants of the Galapagos, 391, 398; on orders, 429 

Hooks on bamboos, 197; to seeds on islands, 392 

Horner, Mr., on the antiquity of Egyptians, 18 

Horns, rudimentary, 454 

Horse, fossil, in La Plata, 318

Horses destroyed by flies in La Plata, 72; striped, 163; proportions of, when young, 445 

Horticulturists, selection applied by, 32

Huber on cells of bees, 230 

Huber, P., on reason blended with instinct, 208; on habitual nature of instincts, 208; on slave-making

ants, 219-221; on Melipona domestica, 225-226

Humble-bee, 234

Humble-bees, and plant fertilization, 73; compared to hive-bees, 95, 227, also see Bees and Hive-bees; cells of, 225

Humboldt, Mr., 374

Hunter, J., on secondary sexual characters, 150

Hutton, Captain, on crossed geese, 253

Huxley, Prof., on structure of hermaphrodites, 101; on embryological succession, 338; on homologous organs, 438; on the development of aphis, 442

Hybridism, 5, 141, 245, 252, 253, 274-276, 461

Hybrids, 166; sterility of, 245, 248-249, 254, 260-263, 266, 272, 276, 460; self-fertilized, 256; compared to mongrels, 272, 278

Hybrids, fertility of. See Fertility of hybrids.

Hydra, structure of, l90

Icebergs, transporting seeds, 363, 399 

Idealistic morphology, 435, 436 

Immutability of species. See Species, immutability of. 

Inbreeding, 100, 101, 248 Increase, rate of, 63 

Indeterminacy of evolution, 126 

Individuals, numbers favourable to selection, 102; many, whether simultaneously created, 356 

Inheritance, 10, 13, 61, 123, 125, 127, 129, 160, 199, 209, 243, 350, 351, 411, 426, 430, 439, 448, 455; particulate, 3; non-genetic, 11; laws of, 12; pleiotropy, 12; polygeny, 12; at corresponding ages, 14, 86; principle of, 104, 423, 457; cohesion of genotype, 143, 144, 146, 147, 150, 159, 168, 266; Homologous genes, 159; from common parent, 426 

Innate differences. See Differences, innate. 

Insect flowers, 91-92 

Insects, colour of, fitted for habitations, 84; sea-side, colours of, 132; blind, in caves, 138; luminous, 193; neuter, 236; social, 238, see also Bees and Ants. 

Instinct, 8, 91, 172, 185, 207, 209-213, 216, 224, 233, 235-236, 459, 474; definition of, 207; selective advantage of change, 209; fear as, 212; domestic, 213; natural, 215; maternal, 217; slave-making (of ants), 219

Intercrossing-interbreeding effects of, 70-71; advantages of, 96; of individuals, 96, 102-103, 107, 108

Intermediate varieties. See Varieties, transitional.

Islands, 349; oceanic, 388; difference in inhabitants, 400; inhabitants of, 396, 397

Isolating mechanisms, 9, 156, 172, 245, 248, 254, 260, 269, 460

Isolation, 42, 104, 105, 326, 351, 353; favourable to selection, 104; island populations, 106

Java, plants of, 375

Johnston's PhysicalAtlas, 359

Jones, Mr. J.M., on the birds of Bermuda, 391

Jordan's Law, 355

Juan Fernandez Islands, 478

Jussieu on classification, 417

Kerguelen-land, flora of, 381,399 

Kidney-bean, acclimatisation of, 142 

Kidneys of birds, 144 

Kirby on tarsi deficient in beetles, 135 

Knight, Andrew, on cause of variation,7; on reproduction, 96 

Kölreuter on the barberry, 981 on sterility of hybrids, 246, 247,249; on reciprocol crosses, 258; on crossed varieties of nicotiana, 271; opposed to G_rtner, 274; on crossing male and hermaphrodite flowers, 451.

Land bridges, arguments against, 358 

Land-shells, distribution of, 397 

Land of Madeira, naturalised, 402 

Languages, classification of, 422 

Lapse, great, of time, 282 

Larvae, 440 

Larval stages. See Embryos. 

Laurel, nectar secreted by the leaves, 92 

Laws of variation, 131 

Leech, varieties of, 76 

Leguminosae, nectar secreted by glands, 92 

Lepidosiren, 107, 330 

Lepsius, Professor, 27 

Le Roy, Mr., on natural instincts, 214 

Life, struggle for, 60 

Lingula, Silurian, 306 

Linnaeus: on potential of Plant Populations, 64; aphorism of, 413, 417; on homopterous insects, 427 

Linnean Society, 2 

Lion, mane of, 88; young of, striped, 439 

Livingstone, Dr., on African domestic breeds, 34 

Lobelia fulgens, 73, 98

Lobelia, sterility of crosses, 250

Loess of the Rhine, 384

London Catalogue of Plants, (4th edition), 58 

Lowness of structure connected with variability, 149

Lowness, related to wide distribution, 406

Lubbock, Mr., on the nerves of coccus, 46; on the camera lucida, 241

Lucas, Dr. P., on inheritance, 12; on resemblance of child to parent, 275

Lund and Clausen on fossils of Brazil, 339

Lyell, Sir Charles, 2, 292; on the struggle for existence, 62; on modern changes of the earth, 95; on measure of denudation, 283; on a carboniferous land-shell, 289; on fossil whales, 303; on strata beneath Silurian system, 307; on the imperfection of the geological record, 310; on the appearance of species, 312; on Barrande's colonies, 313; on tertiary formations of Europe and North America, 323; on parallelism of tertiary formations, 328; on transport of seeds by icebergs, 363; on great alternations of climate, 382; on the distribution of fresh-water shells, 385; on land-shells of Madeira, 402.

Lyell, Sir Charles, his Principles of Geology, 282

Lyell, Sir Charles, (his 'Manual'), 304

Lyell, Sir Charles, on means of dispersal, 356

Lyell and Dawson on fossilized trees in Nova Scotia, 296.

Madeira, plants of, 107; beetles of, wingless, 135; fossil land-shells of, 339; birds of, 390 

Magpie tame in Norway, 212 

Mainlands (continents) once connected, 357 

Maize, crossed, 270 

Malay Archipelago, 2, 299, 305, 395; compared with Europe, 299; mammals of, 395 

Malconformations, 143-144 

Malpighiaceae, 417 

Malthus, T. R., (doctrine of), 4-5, 63 

Mammae, rudimentary, 451 

Mammals, fossil, in secondary formation, 303; insular, 393 

Man -  Origin of races, 199; as agent of variability, 466-467 

Manatee, rudimentary nails of, 454 

Man-Nature, 83 

'Manual' (of Sir Charles Lyell), 304 

Marshall, Mr., on sheep, 41; horns on cattle, 423 

Marsupials of Australia, 116; fossil species of, 339 

Martens, M., experiment on seeds, 360 

Martin, Mr. W. C., on striped mules, 165 

Maternal instinct. See Instinct, maternal. 

Matteuchi on the electric organs of rays, 193 

Matthiola, reciprocal crosses of, 258 

Means of dispersal, 356 

Melanism, 275 

Melipona domestica, 225

Memoirs (of Mr. Prestwich), 328 

Metamerism, 437 

Metamorphism of oldest rocks, 308 

Mice destroying bees, 74; acclimatisation of, 141 

Migration: 293, 351, 353, 380, 384, 404, 407-410, 462, 477; bears on first appearance of fossils, 296; obstacles to 347; see also Dispersal. 

Miller, Hugh, Geologist, 283 

Miller, Prof., on the cells of bees, 226 

Mirabilis, crosses of, 258 

Missel-thrush, 76 

Misseltoe, complex relations of, 3 

Mississippi, rate of deposition at mouth, 284 

Mocking-thrush of the Galapagos, 402 

Modification, 85, 106, 120-3, 125, 128, 143, 169, 170, 173, 176, 205, 237, 314, 327, 355, 381, 420, 425, 457, 466; of simpler instincts, 235; process of, 343, 356; of species, how far applicable, 483 

Moles, blind, 137 

Mongrels compared to hybrids. See Hybrids compared to mongrels. Mongrels, fertility and sterility of, 267; and hybrids compared, 272 Monkeys, fossil, 303 

Monocanthus, 424 

Mons, Van, on the origin of fruit-trees, 29, 39 

Monsters, 424, see also 

Monstrosities. Monstrosities (individual anomalies), 155, 443, 452

Moquin-Tandon on sea-side plants, 132 

Moreton, Lord, hybrid horses, 165 

Morphology, 434-439, 456-458; heritage of idealistic, 435, 436 

Mozart, musical powers of, 209 

Mud, seeds in, 386 

Mules, striped, 165

Muller, Dr. F., 10; on Alpine Australian plants, 375 

Murchison, Mr., on the formations of Russia, 389; on axoic formations, 307; catashophist, 317; on extinction, 317 

Murray, Hon. C., 20 

Mustela vison, 179 

Mutation, 320, 325, 336, 480 

Mutilation, 135 

Myanthus, 424 

Myrmecocystus, 238 

Myrmica, eyes of, 240

Natural economy. See Nature, economy of.

Natural history, selection, 80; system, 413; future progress of, 484; revolution in, 484

Natural instincts. See Instincts, natural.

Naturalisation of plants, 114-115; of forms distinct from indigenous species, 115; in New Zealand, 201

Natural selection, 6, 15, 30, 32, 38, 45, 46, 60, 61, 79, 80, 81, 82, 84, 95, 104, 108, 116, 121, 123, 127-129, 133-134, 136, 138, 141, 143, 147, 149, 152-153, 156, 158, 161, 169, 171, 172, 177, 179, 181, 186, 190, 191, l92, 194, 200-201, 209, 211, 224, 233, 235, 237, 239, 242, 281, 317, 320, 325, 343, 345, 351, 382, 392, 401, 433, 435, 437, 454_456, 460, 467, 469, 471-472, 475, 478, 489; difficulties, 5, 235, 242, 465; definition, 61, 87, 109, 470; selective value, 61, 145, 209; emphemistic description, 79; by-products, 86; sexual, 87, 156, 468; stabilizing selection, 104, 127, 474; slowness and intermittency, 108, 282; alternatives, 196; deleterious characters, 201; relativity, 202

Natural System, 413, 422, 433, 449, 456, 478-479; founded on descent with modification, 420

"Natura non facit saltum, " 243, 460, 471

Nature, economy of, 62, 76, 81, 102, 104, 122, 158, 331, 412, 414, 418, 455, see also Nature, polity of.

Nature-man. See Man-nature. 

Nature-nurture, 133, 

"Nature of Limbs, " by Prof. Owen, 435 

Nature, polity of, 108, 109, 112, 119, 121, 126, see also Nature, economy of. 

Nature, scale of, 88, 149, 235, 313, 345, 468 

Nature, war of, 79, 490 

Nautilus, Silurian, 306 

Nectar of plants, 92 

Nectaries, how formed, 92 

Nelumbium luteum, 387 

Nests, variation in, 212 

Neuter insects, 236 

New forms, 320 

Newman, Mr., on humble-bees, 74 

New systematics, 298 

New Zealand, productions of, not perfect, 201; naturalised products of, 337; fossil birds of, 339; glacial action in, 373; crustaceans of, 376; algae of, 376; number of plants of, 389; flora of, 399 Nicotiana, certain species very sterile, 257; crossed varieties of, 271 Noble, Mr., on fertility of Rhododendron, 251 

Nodules, phosphatic in azoic rocks, 307

Onites apelles, 135 

Orchis, pollen of, 193 

Organic beings, distribution of, 47 

Organic chain, 280 

Organis of extreme perfection, 186; electric, of fishes, 192-193; of little importance, 194; classificatory importance of, 415; homologous, 434; rudiments of, 450 

Origin of species, 1, 2, 6, 484 

Ornithorhynchus, 107, 416 

Ostrich not capable of flight, 134; habit of laying eggs together, 218; American, two species of, 349 

Otter, habits of, how acquired, 179 

Ouzel, water, 185 

Owen, Prof., on birds not flying, 134; on vegetive repetition, 149; on variable length of arms in ouran-outang, 150; on the swim-bladder of fishes, 191; on electric organs, 192; on fossil horse of La Plata, 319; on relations of ruminants and pachyderms, 329; on fossil birds of New Zealand, 339; on succession of types, 339; on affinities of the dugong, 414; on fish and reptiles, 416; on homologous organs, 435; on skulls of birds, 437; on the metamorphosis of cephalopods and spiders, 442; on leg bones, 452

Palaeontology, of Prof. Pictet, 305

Paley on no organ formed to give pain, 201

Pallas on the fertility of the wild stocks of domestic animals, 253

Paraguay, cattle destroyed by flies, 72

Parasites, 217

Parent-form, reference to, 91, 134, 179, 187, 273-274,

280-281, 298, 301, 303, 315, 424, 429, 466

Parent-species, reference to, 7, 16, 57, 121, 124, 249, 255, 281-282, 297, 320, 433, 446

Parent- stocks, 19, 2 3

Partridge, dirt on feet, 362

Parts greatly developed, variable, 150; degrees of utility, of, 201

Parus major, 183

Passiflora, 251

Peaches in United States, 85

Pear, grafts of, 261

Pelargonium, flowers of, 145; sterility of, 251

Pelvis of women, 144

Peloria, 145

Perfection, absolute, impossible through natural selection, 202; progress towards (through natural selection), 489

Period, glacial, 365

Petrels, habits of, 184

Phasianus, fertility of hybrids, 253

Pheasant, young, wild, 216

Phenotype: constancy of, 134; incidental by-products of, 146 

Philippi on tertiary species in Sicily, 312 

Phylogenetic tree, 332 

PhysicalAtlas, Johnston's, 359 

"Physiological division of labor," 93 

Pictet, Prof., on groups of species suddenly appearing, 302, 305; his Palaeontology, 303: on rate of organic change, 313; on continuous succession of genera, 316 on close alliance of fossils in consecutive formations, 335; on embryological succession, 338 

Pierce, Mr., on varieties of wolves, 9l 

Pigeons, with feathered feet and skin between toes, 12; breeds described, and origin of 20; domestic, 20; breeds of, how produced, 39, 42; tumbler, not being able to get out of egg, 87; reverting to blue colour, 160; instinct of tumbling, 214; carriers, killed by hawks, 362, young of, 445 

Pistil, rudimentary, 451 

Plants, poisonous, not affecting certain coloured animals, 12; selection applied to, 32; gradual improvement of, 37; not improved in barbarous countries, 38; destroyed by insects, 67; in midst of range, have to struggle with other plants, 77; nectar of, 92; fleshy, on sea-shores, 132; fresh-water, distribution of, 386; low in scale, widely distributed, 406 

Pliny, reference to, 34, 37 

Pliocene period, 370-371

Plumage, laws of change in sexes of birds, 89

Plums in the United States, 85

Pointer dog, origin of, 35; habits of, 213

Poison not affecting certain coloured animals, 12

Poison, similar effect of, on animals and plants, 484

Polity of Nature. See Nature, polity of.

Pollen of fir-trees, 203

Polyphenism, 241

Poole, Col., on striped hemionus, 163-164, 166

Population, 81, 102, 105, 212, 240, 459; allopatric, 51

Potamogeton, 387

Precambrian life, 307

Predation, 67

Preservation, 125

Prestwich, Mr., on English and French eocene formations, 328,

Primative organisms, 313

Primrose, 49; sterility of, 247

Primula, varieties of, 49

PrinciplesofGeology, (of Sir Charles Lyell), 282

Progenitor, common, 157-158

Proteolepas, 148

Proteus, 139

Psychology, future progress of, 488

Quantitative approach, 445

Quince, grafts of, 261

Races, domestic, 15; geographical, 48

Race-horses, Arab, 35; English, 356

Radiation, adaptive, 303

Ramond on plants of Pyrenees, 368

Ramsay, Prof ., on thickness of the British formations, 284; on faults, 285

Range, restricted, 470

Rate of evolution, 183, 266; factors controlling, 313-314; of taxa, 316

Ratio of increase, 63

Rats, supplanting each other, 76; blind in cave, 137; acclimatisation of, 141

Rattle-snake, 201

Reason and instinct, 208

Recapitulation, general, 459

Reciprocity of crosses, 258

Record, geological, imperfect, 279

Relationship, faunal, 398, 403, 478; in time and space, 410

Rengger on flies destroying cattle, 72

Reproduction, 10, 43, 65, 81, 100, 134, 260, 460; rate of 63

Resemblance to parents in mongrels and hybrids, 273

Reversion, law of inheritance, 14, 153, 158, 160-162, 169, 199; in pigeons to blue colour, 160

Rhododendron, sterility of, 2 51

Richard, Prof., on Aspicarpa, 417

Richardson, Sir J., on structure of squirrels, 180; on fishes of the southern hemisphere, 376 

Robinia, grafts of, 262 

Rodents, blind, 137 

Rollin, Mr., on mules, 165 

Rudimentary organs (or parts) 149, 161, 168, 416, 450, 451, 454, 455, 457; origin of, 454 

Rudiments important for classification, 416

Sageret on grafts, 262 

Salmons, males fighting, and hooked jaws of, 88 

Salt-water, how far injurious to seeds, 358 

Saurophagus sulphuratus, 183 

Scale of nature. See Nature, scale of. 

Schiodte on blind insects, 138 

Schlegel on snakes, 144 

Sea-water, how far injurious to seeds, 358 

Sebright, Sir John, 31; on crossed animals, 20; on selection of pigeons, 31 

Secondary sexual characters, 150-151, 156, 169 

Sedgwick, Prof., on groups of species suddenly appearing, 302 Seedlings destroyed by insects, 67 

Seeds, nutriment in, 77; winged, 146; power of resisting salt-water, 358; in crops and intestines of birds, 361; eaten by fish, 362, 387; in mud, 386: hooked, on islands, 392 

Selection of domestic products, 29; accumulative ( in domestic animals), 30; principle not of recent origin, 33; unconscious, 34, 36; natural, 80; sexual, 87, 88, 89, 127, 156, 158, 196, 199; natural, circumstances favourable to, 101; artificial, 109 

Self-fertilization, 98-100 

Self-fertilization (of hybrids). See Hybrids, self-fertilized. 

Series, morphological vs. phylogenetic, 330 

Sexes, relations of, 87

Sexual selection, 87; characters variable, 156

Sheep, ancon, example of mutation, 30; Merino, their selection, 31; two sub-breeds unintentionally produced, 36; mountain, varieties of, 76

Shells, colours of, 132; littoral, seldom embedded, 288; fresh-water, dispersal of, 385; of Madeira, 391; land, distribution, 397

Silene, fertility of crosses, 257

Silliman, Prof., on blind rat, 137

Similarity, 425-427

Slave-making instinct (of antsl. See instincts, slavemaking.

Small changes, accumulation of. See Accumulation of small changes.

Smith, Col. Hamilton, on gtriped horses, 164

Smith, Mr. Fred., on slave-making ants, 219; on neuter ants, 239-240

Smith, Mr., of Jordan Hill, on the degradation of coastrocks, 283

Snap-dragon, 161

Social insects. See:Insects, social; Bees; and Ants.

Somerville, Lord, on selection of sheep, 31

Sorbus, grafts of, 262

Spaniel, King Charles's breed, 35

Specialization, 105, 110, 111, 174, 302, 326, 399-400; sympatric, 52, 103, 114, 120, 128, 174, 177; geological, 302-303, 457

Species, 29, 48, 52, 58, 59, 133-134, 171, 177, 248, 268, 293, 299, 321, 326, 404, 469, 484; independently created, 6, see also Creation; distinct, 29, 61, 159, 302, 354; definition, 44, 47, 52, 56-57, 248, 296-297, 424; polymorphic, 46; species-variety, problem of, 47, 49, 59, 278, 297; incipient, 52, 53-55, 61, 111, 125, 169, 325, 470; common, variable, 53; dominant, 53, 326, 343, 470; in large genera variable, 54; differences between, 111, 128; domestic, 253-254; distinction between 299; groups of, suddenly appearing, 302, 306; beneath Silurian formations, 306; immutability of, 310, 312; successively appearing, 312; rare, 31g; changing simultaneously throughout the world, 322; extinct, 329; affinity of 329, 397; common, 350, closely allied, 404 

Species area, 102, 105-108, 174-175, 205, 350, 353, 470 

Specific characters. See Characters, specific. 

Spencer, Lord, on increase in size of cattle, 35 

Sphex, parasitic, 218 

Spiders, development of 442 

Spitz-dog crossed with fox, 268 

Sports, in plants, 9, 132

Sprengel, C. C., on crossing, 98; on ray-florets, 145 

Squirrels, gradations in structure, 180 

Stabilization, phenotypic, 149 

Staffordshire, heath, changes in, 72 

Stag-beetles, fighting, 88 

Sterility from changed conditions of life, 9; of hybrids, 246; laws of, 254; causes of, 263; from unfavourable conditions, 265; of certain varieties, 269; see also Isolating mechanisms. 

Sterility of hybrids. See Hybrids, sterility of. 

St. Helena, productions of, 389 

St. Hilaire, Aug., on classification, 418 

St. John, Mr., on habits of cats 91 

Sting of bee, 202 

Stocks, aboriginal, of domestic animals, 18 

Strata, thickness of, in Britain, 284 

Stripes on horses, 163 

Structure, degrees of utility of, 201 

Struggle for existence, 53, 60, 61, 62, 63, 68, 78, 110, 125, 186, 235, 344, 433, 467, 480 Struggle for life, 405 

Succession, geological, 312; of types in same areas, 338 

"Succession of type, " law of, 339 

Survival, 81 

Swallow, one species supplanting another, 76 

Swim-bladder, 190 

Sympatry, 402 

System, natural, 413; see also Classification and Natural system. 

Systematics, systematists, 45, 268, 298, 426, 427; empiracal findings of, 466; see also Classification.

Tapir, 281 Tarsi deficient, 135 

Tausch on umbelliferous flowers, 146 

Taxonomic characters, 154 

Teeth and hair correlated, 144; rudimentary, im embryonic calf, 450, 480; embryonic, traces of, in birds, 451 

Tegetmeier, Mr., on cells of bees, 228, 233 

Temminck on distribution aiding classification, 419 

Tertiary, later, 371 

Thouin on grafts, 262 

Thrush, aquatic species of, 185; mocking, of the Galapagos, 402; young of, spotted, 439; nest of, 243 

Thuret, M., on crossed fuci, 258, 264 

Thwaites, Mr., on acclimatisation, 140 

Tierra del Fuego, dogs of, 215; plants of, 374, 378 

Timber-drift, 360 

Time, lapse of, 282; geological, 282 

Titmouse, 183 

Toads on islands, 393 

Tobacco, crossed varieties of 271 

Tomes, Mr., on the distribution of bats, 394 

Transmitionsal forms, 173, 17g, 183, see also Varieties, transmitional. 

Transmitional structures, 180 

Transitional varieties. See Varieties, transitional.

Transitions in varieties rare, 172 

Transport, accidental, (of seeds), 365 

Tree of life, 130 

Trees, with separated sexes, 99; on islands belong to peculiar orders, 392 

Trifolium pratense, 73, 94; incarnatum, 94 

Trigonia, 321 

Trilobites, 306; sudden extinction of, 321 

Troglodytes, 243 

Tucutucu, blind, 137 

Tumbler pigeons, habits of, hereditary, 214, young of, 446 

Turkey-cock, brush of hair on breast, 90 

Turkey, naked skin on head, l97; young, wild, 216 

Turnip and cabbage, analogous variations of, 159 

Type, unity of, 206 

Types, succession of, in same areas, 338 

Typology, 104, 206, 438

Ulex, young leaves of, 439

Umbelliferae, outer and inner florets of, 144

Unconscious selection. See Selection, unconscious.

"Unity of design." See Design, unity of.

Unity of Type. See Type, unity of.

Use, 133, 148, 199; effects of, under domestication, 11; effects of, in a state of nature, 134; see also Disuse; and Use and Disuse.

Use and Disuse (combined reference), 43, 134, 137, 143, 243, 466, 472, 486

Utility, how far important in the construction of each part, 199

Variability, reference to, 8, 19, 43, 82, 118, 134, 150-151, 156, 314, 351, 466, generative, 154; of mongrels and hybrids, 274; see also Variation .

Variation, 4, 7, 32, 44, 45, 46, 80, 81, 110, 127, 133, 149, 152, 153, 154-155, 158, 162, 167, 169, 177, 198, 204, 209-212, 272, 297, 314, 443, 444, 447, 455; under domestication, 4, 7; cause of, 7, 43, 82, 466-467; caused by reproductive system being affected by conditions of life, 8; non-inherited, 12; drastic, 32, 325, 336; induced, 43; under nature, 44; polymorphism, 46, 91; geographical, 51, 132, 212, 298, 342; laws of, 131; rules of geographic, 132; homologous, 159; successive (principle of ) 479

Variations appear at corresponding ages, 14, 86; analogous in distinct species, 159

Varieties or incipient species, natural, 44; struggle between, 75; domestic, extinction of, 111; transitional, rarity of, 172; when crossed, fertile, 267; when crossed, sterile, 269; intermediate, 299; similarity of, 350; classification of, 423; see also Incipient species.

Varieties, transitional, (varieties, intermediate), 172, 174, 203, 280, 297-299, 463

Variety, reference to, 30, 44, 48, 51, 52, 54, 55, 58, 59, 91, 103, 111, 119, 169, 176, 247-248, 267-268, 280, 325, 350, 404, 457, 459

Variety-species, problem of. See Species-variety. 

"Vegetative repetition," 149 

Verbascum, sterility of, 251; varieties of, crossed, 270 

Verneuil, M. de, on the succession of species, 325 

"Vestiges of Creation," author of (R. Chambers not designated) Viola tricolor, 73 

Volcanic islands, denudation of, 284 

Vulture, naked skin on head, 197

Wallace, Mr., on origin of species, 2; on law of geographical distrobution, 355; on the Malay Archipelago, 395

War of nature. See Nature, war of.

Wasp, sting of, 202

Water, fresh, productions of, 383

Water-hen, 185

Waterhouse, Mr., on Australian marsupials, 116; on greatly developed parts being variable, 150, 151; on the cells of bees, 225; on general affinities, 429

Water-ouzel, 185

Watson, Mr..H.C., on British plants, 48; on species and varieties, 53; on range of varieties of British plants, 58; on acclimatisation, 140; on rarity of intermediate varieties, 176; on flora of Azores,363; on Alpine plants, 367,376

Weald, denudation of, 285

Web of feet in water-birds, 185

West Indian islands, mammals of, 395

Westwood on species in large gerera being closely allied to others, 57; on the tarsi of Engidae, 157; on the antennae of hymenopterous insects, 416

Whales, fossil, 303

Wheat, varieties.of, 113

White Mountains, flora of, 365

Wings, reduction of size, 134

Wings of insects homologous with branchiae, 191; rudimentary, in insects, 451

Wolf, crossed with dog, 214; of Falkland Isles, 393

Wollaston, Mr., on varieties of insects, 48; on fossil varieties of land-shells in Madeira, 52; on colors of insects on sea-shore, 132; on wingless beetles, 135, 136; on rarity of intermediate varieties, 176; on insular insects, 389; on land-shells of Madeira, naturalised, 402

Wolves, varieties-of, 90

Woodpecker, habits of, 184; green color of, 197

Woodward, Mr., on the duration of specific forms, 293; on the continuous succession of genera, 316; on the succession of types, 339

World, species changing simultaneously throughout, 322

Wrens, nest of, 243

Zebra, stripes on, 163