A.
Aberrant groups, 429.
Abyssinia, plants of, 375.
Acclimatisation, 139.
Affinities of extinct species, 329.
—— of organic beings, 411.
Agassiz on Amblyopsis, 139.
—— on groups of species suddenly appearing, 302, 305.
—— on embryological succession, 338.
—— on the glacial period, 366.
—— on embryological characters, 418.
—— on the embryos of vertebrata, 439.
—— on parallelism of embryological development and geological succession, 449.
Algæ of New Zealand, 376.
Alligators, males, fighting, 88.
Amblyopsis, 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.
Analogy of variations, 159.
Ancylus, 386.
Animals, not domesticated from being variable, 17.
——, domestic, descended from several stocks, 19.
————, acclimatisation of, 141.
—— of Australia, 116.
—— with thicker fur in cold climates, 133.
——, blind, in caves, 137.
——, extinct, of Australia, 339.
Anomma, 240.
Antarctic islands, ancient flora of, 399.
Antirrhinum, 161.
Ants attending aphides, 210.
——, slave-making instinct, 219.
——, neuter, structure of, 236.
Aphides, attended by ants, 210.
Aphis, development of, 442.
Apteryx, 182.
Arab horses, 35.
Aralo-Caspian Sea, 339.
Archaic, M. de, on the succession of species, 325.
Artichoke, Jerusalem, 142.
Ascension, plants of, 389.
Asclepias, pollen of, 193.
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 flies destroying cattle, 72.
Azores, flora of, 363.
B.
Babington, Mr., on British plants, 48.
Balancement of growth, 147.
Bamboo with hooks, 197.
Barberry, flowers of, 98.
Barrande, M., on Silurian colonies, 313.
—— on the succession of species, 325.
—— on parallelism of palæozoic formations, 328.
—— on affinities of ancient species, 330.
Barriers, importance of, 347.
Batrachians on islands, 393.
Bats, how structure acquired, 180.
——, distribution of, 394.
Bear, catching water-insects, 184.
Bee, sting of, 202.
——, queen, killing rivals, 202.
Bees fertilising flowers, 73.
——, 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.
Bentham, Mr., on British plants, 48.
——, on classification, 419.
Berkeley, Mr., on seeds in salt-water, 358.
Bermuda, birds of, 391.
Birds acquiring fear, 212.
—— annually cross the Atlantic, 364.
——, colour of, on continents, 132.
——, footsteps and remains of, in secondary rocks, 304.
——, fossil, in caves of Brazil, 339.
—— of Madeira, Bermuda, and Galapagos, 391.
——, song of males, 89.
—— transporting seeds, 361.
——, waders, 385.
——, with traces of embryonic teeth, 450.
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, 254.
Boar, shoulder-pad of, 88.
Borrow, Mr., on the Spanish pointer, 35.
Bory St. Vincent on Batrachians, 393.
Bosquet, M., on fossil Chthamalus, 305.
Boulders, erratic, on the Azores, 363.
Branchiæ, 190.
Brent, Mr., on house-tumblers, 214.
——, on hawks killing pigeons, 362.
Brewer, Dr., on American cuckoo, 217.
Britain, mammals of, 396.
Bronn on duration of specific forms, 294.
Brown, Robert, on classification, 415.
Buckman on variation in plants, 10.
Buzareingues on sterility of varieties, 270.
C.
Cabbage, varieties of, crossed, 99.
Calceolaria, 251.
Canary-birds, sterility of hybrids, 252.
Cape de Verde islands, 398.
Cape of Good Hope, plants of, 110, 375.
Carrier-pigeons killed by hawks, 362.
Cassini on flowers of compositæ, 145.
Catasetum, 424.
Cats, with blue eyes, deaf, 12.
——, variation in habits of, 91.
—— curling tail when going to spring, 201.
Cattle destroying fir-trees, 72.
—— destroyed by flies in La Plata, 72.
——, breeds of, locally extinct, 111.
——, fertility of Indian and European breeds, 254.
Cave, inhabitants of, blind, 137.
Centres of creation, 352.
Cephalopodæ, development of, 442.
Cervulus, 253.
Cetacea, teeth and hair, 144.
Ceylon, plants of, 375.
Chalk formation, 322.
Characters, divergence of, 111.
——, sexual, variable, 156.
——, adaptive or analogical, 426.
Charlock, 76.
Checks to increase, 67.
—— ——, mutual, 71.
Chickens, instinctive tameness of, 216.
Chthamalinæ, 289.
Chthamalus, cretacean species of, 305.
Circumstances favourable to selection of domestic products, 40.
—— —— to natural selection, 102.
Cirripedes capable of crossing, 101.
——, carapace aborted, 148.
——, their ovigerous frena, 192.
——, fossil, 304.
——, larvæ of, 440.
Classification, 413.
Clift, Mr., on the succession of types, 339.
Climate, effects of, in checking increase of beings, 68.
——, adaptation of, to organisms, 139.
Cobites, intestine of, 190.
Cockroach, 76.
Collections, palæontological, poor, 288.
Colour, influenced by climate, 132.
——, in relation to attacks by flies, 198.
Columba livia, parent of domestic pigeons, 23.
Colymbetes, 386.
Compensation of growth, 147.
Compositæ, outer and inner florets of, 144.
——, male flowers of, 451.
Conclusion, general, 480.
Conditions, slight changes in, favourable to fertility, 267.
Coot, 185.
Coral-islands, seeds drifted to, 361.
—— reefs, indicating movements of earth, 310.
Corn-crake, 186.
Correlation of growth in domestic productions, 11.
Cowslip, 49.
Creation, single centres of, 352.
Crinum, 250.
Crosses, reciprocal, 258.
Crossing of domestic animals, importance in altering breeds, 20.
——, advantages of, 96.
—— unfavourable to selection, 102.
Crustacea of New Zealand, 376.
Crustacean, blind, 137.
Cryptocerus, 239.
Ctenomys, blind, 137.
Cuckoo, instinct of, 216.
Currants, grafts of, 262.
Currents of sea, rate of, 360.
Cuvier on conditions of existence, 206.
—— on fossil monkeys, 304.
——, Fred., on instinct, 208.
D.
Dana, Prof., on blind cave-animals, 139.
——, on relations of crustaceans of Japan, 372.
——, on crustaceans of New Zealand, 376.
De Candolle on struggle for existence, 62.
—— on umbelliferæ, 146.
—— on general affinities, 430.
——, Alph., on low plants, widely dispersed, 406.
——, ——, 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.
——, ——, on insular plants, 389.
Degradation of coast-rocks, 282.
Denudation, rate of, 285.
—— of oldest rocks, 308.
Development of ancient forms, 336.
Devonian system, 334.
Dianthus, fertility of crosses, 256.
Dirt on feet of birds, 362.
Dispersal, means of, 356.
—— during glacial period, 365.
Distribution, geographical, 346.
——, means of, 356.
Disuse, effects of, under nature, 134.
Divergence of character, 111.
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.
——, —— of crosses, 268.
——, proportions of, when young, 444.
Domestication, variation under, 7.
Downing, Mr., on fruit-trees in America, 85.
Downs, North and South, 286.
Dragon-flies, 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.
E.
Earl, Mr. W., on the Malay Archipelago, 395.
Ears, drooping, in domestic animals, 11.
——, rudimentary, 454.
Earth, seeds in roots of trees, 361.
Eciton, 238.
Economy of organisation, 147.
Edentata, teeth and hair, 144.
——, fossil species of, 339.
Edwards, Milne, on physiological divisions of labour, 115.
——, on gradations of structure, 194.
——, on embryonical characters, 418.
Eggs, young birds escaping from, 87.
Electric organs, 192.
Elephant, rate of increase, 64.
—— of glacial period, 141.
Embryology, 438.
Existence, struggle for, 60.
——, conditions of, 206.
Extinction, as bearing on natural selection, 109.
—— of domestic varieties, 111,
——, 317.
Eye, structure of, 187.
——, correction for aberration, 202.
Eyes reduced in moles, 137.
F.
Fabre, M. on parasitic sphex, 218.
Falconer, Dr., on naturalisation of plants in India, 65.
—— on fossil crocodile, 313.
—— on elephants and mastodons, 334.
—— and Cautley on mammals of sub-Himalayan beds, 340.
Falkland Island, wolf of, 394.
Faults, 285.
Faunas, marine, 348.
Fear, instinctive, in birds, 212.
Feet of bird, young molluscs adhering to, 385.
Fertility of hybrids, 249.
—— from slight changes in conditions, 267.
—— of crossed varieties, 268.
Fir-trees destroyed by cattle, 72.
—— ——, pollen of, 203.
Fish, flying, 182.
——, teleostean, sudden appearance of, 305.
——, fresh-water, distribution of, 384.
Fishes, ganoid, now confined to fresh water, 107.
——, electric organs of, 192.
——, ganoid, living in fresh water, 321.
—— of southern hemisphere, 376.
Flight, powers of, how acquired, 182.
Flowers, structure of, in relation to crossing, 97.
—— of compositæ and umbelliferæ, 144.
Forbes, E., on colours of shells, 132.
—— on abrupt range of shells in depth, 175.
—— on poorness of palæontological collections, 288.
—— on continuous succession of genera, 316.
—— on continental extensions, 357.
—— on distribution during glacial period, 366.
—— on parallelism in time and space, 409.
Forests, changes in, in America, 74.
Formation, Devonian, 334.
Formations, thickness of, in Britain, 284.
——, intermittent, 290.
Formica rufescens, 219.
—— sanguinea, 219.
—— flava, neuter of, 240.
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.
Fur, thicker in cold climates, 133.
Furze, 439.
G.
Galapagos Archipelago, birds of, 390.
Galeopithecus, 181.
Game, increase of, checked by vermin, 68.
Gärtner on sterility of hybrids, 247, 255.
——, on reciprocal crosses, 258.
——, on crossed maize and verbascum, 270.
——, on comparison of hybrids and mongrels, 272.
Geese, fertility when crossed, 253.
——, upland, 185.
Genealogy important in classification, 425.
Geoffroy St. Hilaire on balancement, 147.
—— —— on homologous organs, 434.
—— ——, Isidore, on variability of repeated parts, 149.
—— ——, on correlation in monstrosities, 11.
—— ——, on correlation, 144.
—— ——, on variable parts being often monstrous, 155.
Geographical distribution, 346.
Geography, ancient, 487.
Geology, future progress of, 487.
——, imperfection of the record, 279.
Giraffe, tail of, 195.
Glacial period, 365.
Gmelin on distribution, 365.
Gnathodon, fossil, 368.
Godwin-Austen, Mr., on the Malay Archipelago, 300.
Goethe on compensation of growth, 147.
Gooseberry, grafts of, 262.
Gould, Dr. A., on land-shells, 397.
——, Mr., on colours of birds, 132.
——, on birds of the Galapagos, 398.
——, on distribution of genera of birds, 404.
Gourds, crossed, 270.
Grafts, 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.
——, Dr. J. E., on striped mule, 165.
Grebe, 185.
Groups, aberrant, 429.
Grouse, colours of, 84.
——, red, a doubtful species, 49.
Growth, compensation of, 147.
——, correlation of, in domestic products, 11.
——, correlation of, 143.