Heusinger, on white animals poisoned by certain plants, 9.
Hewitt, Mr., on sterility of first crosses, 249.
Hildebrand, Prof., on the self-sterility of Corydalis, 238.
Hilgendorf, on intermediate varieties, 275.
Himalaya, glaciers of, 335.
—, plants of, 337.
Hippeastrum, 238.
Hippocampus, 189.
Hofmeister, Prof., on the movements of plants, 197.
Holly-trees, sexes of, 73.
Hooker, Dr., on trees of New Zealand, 78.
—, on acclimatisation of Himalayan trees, 112.
—, on flowers of umbelliferæ, 116.
—, on the position of ovules, 172.
—, on glaciers of Himalaya, 335.
—, on algæ of New Zealand, 338.
—, on vegetation at the base of the Himalaya, 338.
—, on plants of Tierra del Fuego, 336.
—, on Australian plants, 337, 355.
—, on relations of flora of America, 340.
—, on flora of the Antarctic lands, 341, 354.
—, on the plants of the Galapagos, 349, 354.
—, on glaciers of the Lebanon, 335.
—, on man not causing variability, 62.
—, on plants of mountains of Fernando Po, 337.
Hooks on palms, 158.
—, on seeds, on islands, 349.
Hopkins, Mr., on denudation, 274.
Hornbill, remarkable instinct of, 234.
Horns, rudimentary, 400.
Horse, fossil in La Plata, 294.
—, proportions of, when young, 392.
Horses destroyed by flies in Paraguay, 56.
—, striped, 128.
Horticulturists, selection applied by, 23.
Huber on cells of bees, 224.
Huber, P., on reason blended with instinct, 205.
—, on habitual nature of instincts, 206.
—, on Melipona domestica, 220.
Hudson, Mr., on the Ground-woodpecker of La Plata, 142.
—, on the Molothrus, 215.
Humble-bees, cells of, 221.
Hunter, J., on secondary sexual characters, 119.
Hutton, Captain, on crossed geese, 240.
Huxley, Prof., on structure of hermaphrodites, 79.
—, on the affinities of the Sirenia, 302.
—, on forms connecting birds and reptiles, 302.
—, on homologous organs, 386.
—, on the development of aphis, 390.
Hybrids and mongrels compared, 259.
Hybridism, 235.
Hydra, structure of, 147.
Hymenoptera, fighting, 69.
Hymenopterous insect, diving, 142.
Hyoseris, 173.
Ibla, 118.
Icebergs transporting seeds, 329.
Increase, rate of, 50.
Individuals, numbers favourable to selection, 80.
—, many, whether simultaneously created, 322.
Inheritance, laws of, 10.
—, at corresponding ages, 10, 67.
Insects, colour of, fitted for their stations, 66.
—, blind, in caves, 110.
—, luminous, 151.
—, their resemblance to various objects, 181.
—, neuter, 2320.
Instinct, 205.
—,, not varying simultaneously with structure, 229.
Instincts, domestic, 209.
Intercrossing, advantages of, 76, 251.
Islands, oceanic, 347.
Isolation favourable to selection, 81.
Japan, productions of, 334.
Java, plants of, 337.
Jones, Mr. J.M., on the birds of Bermuda, 348.
Jordain, M., on the eye-spots of star fishes, 144.
Jukes, Prof., on subaërial denudation, 267.
Jussieu on classification, 367.
Kentucky, caves of, 111.
Kidney-bean, acclimatisation of, 114.
Kidneys of birds, 115.
Kirby, on tarsi deficient in beetles, 108.
Knight, Andrew, on cause of variation, 5.
Kölreuter, on intercrossing, 76.
—, on the barberry, 77.
—, on sterility of hybrids, 237.
—, on reciprocal crosses, 243.
—, on crossed varieties of nicotiana, 258.
—, on crossing male and hermaphrodite flowers, 397.
Lamarck, on adaptive characters, 373.
Lancelet, 99.
—,, eyes of, 145.
Landois, on the development of the wings of insects, 148.
Land-shells, distribution of, 353.
—, of Madeira, naturalised, 357.
—, resisting salt water, 353.
Languages, classification of, 371.
Lankester, Mr. E. Ray, on longevity, 169.
—, on homologies, 385.
Lapse, great, of time, 266.
Larvæ, 388, 389.
Laurel, nectar secreted by the leaves, 73.
Laurentian formation, 287.
Laws of variation, 106.
Leech, varieties of, 59.
Leguminosæ, nectar secreted by glands, 73.
Leibnitz’ attack on Newton, 421.
—,, limbs in a nascent condition, 398, 399.
Lewes, Mr. G.H., on species not having changed in Egypt, 169.
—, on the Salamandra atra, 397.
—, on many forms of life having been at first evolved, 425.
Life, struggle for, 49.
Lingula, Silurian, 286.
Linnæus, aphorism of, 365.
Lion, mane of, 69.
—, young of, striped, 388.
Lobelia fulgens, 57, 77.
Lobelia, sterility of crosses, 238.
Lockwood, Mr., on the ova of the Hippocampus, 189.
Locusts transporting seeds, 327.
Logan, Sir W., on Laurentian formation, 287.
Lowe, Rev. R.T., on locusts visiting Madeira, 327.
Lowness, of structure connected with variability, 118.
—, related to wide distribution, 359.
Lubbock, Sir J., on the nerves of coccus, 35.
—, on secondary sexual characters, 124.
—, on a diving hymenopterous insect, 142.
—, on affinities, 280.
Lucas, Dr. P., on inheritance, 9.
—, on resemblance of child to parent, 261.
Lund and Clausen, on fossils of Brazil, 310.
Lyell, Sir C., on the struggle for existence, 49.
—, on modern changes of the earth, 75.
—, on terrestrial animals not having been developed on islands, 180.
—, on strata beneath Silurian system, 287.
—, on the imperfection of the geological record, 289.
—, on the appearance of species, 289.
—, on tertiary formations of Europe and North America, 298.
—, on parallelism of tertiary formations, 301.
—, on transport of seeds by icebergs, 328.
—, on great alternations of climate, 342.
—, on the distribution of fresh-water shells, 345.
—, on land-shells of Madeira, 357.
Lyell and Dawson, on fossilized trees in Nova Scotia, 278.
Lythrum salicaria, trimorphic, 254.
Macleay, on analogical characters, 373.
Macrauchenia, 302.
McDonnell, Dr., on electric organs, 150.
Madeira, plants of, 83.
—, beetles of, wingless, 109.
—, birds of, 348.
Magpie tame in Norway, 209.
Males, fighting, 69.
Maize, crossed, 257.
Malay Archipelago, compared with Europe, 280.
—, mammals of, 352.
Malm, on flat-fish, 186.
Malpighiaceæ, small imperfect flowers of, 173.
Malpighiaceæ, 367.
Mammæ, their development, 189.
Mammals, fossil, in secondary formation, 283.
—, insular, 351.
Man, origin of, 428.
Manatee, rudimentary nails of, 400.
Marsupials of Australia, 90.
—,, fossil species of, 382.
—,, structure of their feet, 310.
Martens, M., experiment on seeds, 325.
Martin, Mr. W.C., on striped mules, 129.
Masters, Dr., on Saponaria, 174.
Matteucci, on the electric organs of rays, 150.
Matthiola, reciprocal crosses of, 244.
Maurandia, 197.
Means of dispersal, 323.
Melipona domestica, 220.
Merrill, Dr., on the American cuckoo, 212.
Metamorphism of oldest rocks, 287.
Mice destroying bees, 56.
—, acclimatisation of, 113.
—, tails of, 189.
Miller, Prof., on the cells of bees, 221, 224.
Mirabilis, crosses of, 243.
Missel-thrush, 59.
Mistletoe, complex relations of, 2.
Mivart, Mr., on the relation of hair and teeth, 115.
—, on the eyes of cephalopods, 151.
—, various objections to Natural Selection, 174.
—, on abrupt modifications, 201.
—, on the resemblance of the mouse and antechinus, 373.
Mocking-thrush of the Galapagos, 357.
Modification of species, not abrupt, 424.
Moles, blind, 110.
Molothrus, habits of, 215.
Mongrels, fertility and sterility of, 255.
—, and hybrids compared, 259.
Monkeys, fossil, 284, 285.
Monachanthus, 372.
Mons, Van, on the origin of fruit-trees, 21.
Monstrosities, 33.
Morphology, 382.
Morren, on the leaves of Oxalis, 197.
Moths, hybrid, 240.
Mozart, musical powers of, 206.
Mud, seeds in, 345.
Mules, striped, 129.
Müller, Adolph, on the instincts of the cuckoo, 213.
Müller, Dr. Ferdinand, on Alpine Australian plants, 337.
Müller, Fritz, on dimorphic crustaceans, 35, 233.
—, on the lancelet, 99.
—, on climbing plants, 197.
—, on the self-sterility of orchids, 238.
—, on embryology in relation to classification, 368.
—, on the metamorphoses of crustaceans, 390, 395.
—, on terrestrial and fresh-water organisms not undergoing any metamorphosis, 394.
Multiplication of species not indefinite, 101.
Murchison, Sir, R., on the formations of Russia, 272.
—, on azoic formations, 286.
—, on extinction, 293.
Murie, Dr., on the modification of the skull in old age, 149.
Murray, Mr. A., on cave-insects, 111.
Mustela vison, 138.
Myanthus, 372.
Myrmecocystus, 231.
Myrmica, eyes of, 232.
Nägeli, on morphological characters, 170.
Nails, rudimentary, 400.
Nathusius, Von, on pigs, 159.
Natural history, future progress of, 426.
—, selection, 62.
—, system, 364.
Naturalisation of forms distinct from the indigenous species, 89.
—, in New Zealand, 163.
Naudin, on analagous variations in gourds, 125.
—, on hybrid gourds, 258.
—, on reversion, 260.
Nautilus, Silurian, 286.
Nectar of plants, 73.
Nectaries, how formed, 73.
Nelumbium luteum, 346.
Nests, variation in, 208, 228, 234.
Neuter insects, 230, 231.
New Zealand, productions of, not perfect, 163.
—, naturalised products of, 309.
—, fossil birds of, 310.
—, glaciers of, 335.
—, crustaceans of, 338.
—, algæ of, 338.
—, flora of, 354.
—, number of plants of, 374.
Newman, Col., on humble-bees, 57.
Newton, Prof., on earth attached to a partridge’s foot, 328.
Newton, Sir I., attacked for irreligion, 421.
Nicotiana, crossed varieties of, 258.
—, certain species very sterile, 243.
Nitsche, Dr., on the Polyzoa, 193.
Noble, Mr., on fertility of Rhododendron, 239.
Nodules, phosphatic, in azoic rocks, 287.
Oaks, variability of, 40.
Œnonis, small imperfect flowers of, 173.
Onites apelles, 108.
Orchids, fertilisation of, 154.
—, the development of their flowers, 195.
—, forms of, 372.
Orchis, pollen of, 151.
Organisation, tendency to advance, 97.
Organs of extreme perfection, 143.
—, electric, of fishes, 150.
—, of little importance, 156.
—, homologous, 382.
—, rudiments of, and nascent, 397.
—, mammæ of, 190.
Ostrich not capable of flight, 180.
—, habit of laying eggs together, 215.
—, American, two species of, 318.
Otter, habits of, how acquired, 138.
Ouzel, water, 142.
Owen, Prof., on birds not flying, 108.
—, on vegetative repetition, 118.
—, on variability of unusually developed parts, 119.
—, on the eyes of fishes, 145.
—, on the swim-bladder of fishes, 148.
—, on fossil horse of La Plata, 294.
—, on generalised form, 301.
—, on relation of ruminants and pachyderms, 303.
—, on fossil birds of New Zealand, 310.
—, on succession of types, 310.
—, on affinities of the dugong, 365.
—, on homologous organs, 383.
—, on the metamorphosis of cephalopods, 390.
Pacific Ocean, faunas of, 317.
Pacini, on electric organs, 151.
Paley, on no organ formed to give pain, 163.
Pallas, on the fertility of the domesticated descendants of wild stocks, 241.
Palm with hooks, 158.
Papaver bracteatum, 174.
Paraguay, cattle destroyed by flies, 56.
Parasites, 215.
Partridge, with ball of dirt attached to foot, 328.
Parts greatly developed, variable, 119.
Parus major, 141.
Passiflora, 238.
Peaches in United States, 66.
Pear, grafts of, 246.
Pedicellariæ, 191.
Pelargonium, flowers of, 166.
—, sterility of, 239.
Peloria, 116.
Pelvis of women, 115.
Period, glacial, 330.
Petrels, habits of, 142.
Phasianus, fertility of hybrids, 240.
Pheasant, young, wild, 211.
Pictet, Prof., on groups of species suddenly appearing, 282.
—, on rate of organic change, 291.
—, on continuous succession of genera, 293.
—, on change in latest tertiary forms, 278.
—, on close alliance of fossils in consecutive formations, 306.
—, on early transitional links, 283.
Pierce, Mr., on varieties of wolves, 71.
Pigeons with feathered feet and skin between toes, 9.
—, breeds described, and origin of, 15.
—, breeds of, how produced, 28, 30.
—, tumbler, not being able to get out of egg, 68.
—, reverting to blue colour, 127.
—, instinct of tumbling, 210.
—, young of, 392.
Pigs, black, not affected by the paint-root, 9.
—, modified by want of exercise, 159.
Pistil, rudimentary, 397.
Plants, poisonous, not affecting certain coloured animals, 9.
—, selection, applied to, 27.
—, gradual improvement of, 27.
—, not improved in barbarous countries, 27.
—, destroyed by insects, 53.
—, in midst of range, have to struggle with other plants, 60.
—, nectar of, 73.
—, low in scale, widely distributed, 359.
Pleuronectidæ, their structure, 186.
Plumage, laws of change in sexes of birds, 70.
Plums in the United States, 66.
Pointer dog, origin of, 25.
—, habits of, 210.
Poison not affecting certain coloured animals, 9.
Poison, similar effect of, on animals and plants, 425.
Pollen of fir-trees, 164.
—, transported by various means, 154, 161.
Pollinia, their development, 195.
Polyzoa, their avicularia, 193.
Poole, Col., on striped hemionus, 128.
Potemogeton, 346.
Pouchet, on the colours of flat-fish, 188.
Prestwich, Mr., on English and French eocene formations, 300.
Proctotrupes, 142.
Proteolepas, 118.
Proteus, 112.
Psychology, future progress of, 428.
Pyrgoma, found in the chalk, 284.
Quagga, striped, 129.
Quatrefages, M., on hybrid moths, 240.
Quercus, variability of, 40.
Quince, grafts of, 246.
Rabbit, disposition of young, 211.
Races, domestic, characters of, 12.
—, English, 323.
Radcliffe, Dr., the electrical organs of the torpedo, 150.
Ramond, on plants of Pyrenees, 331.
Ramsay, Prof., on subaërial denudation, 267.
—, on thickness of the British formations, 268, 269.
—, on faults,.
Ramsay, Mr., on instincts of cuckoo, 213.
Ratio of increase, 50.
Rats, supplanting each other, 59.
—, acclimatisation of, 113.
—, blind, in cave, 110.
Rattle-snake, 162.
Reason and instinct, 205.
Recapitulation, general, 404.
Reciprocity of crosses, 243.
Record, geological, imperfect, 264.
Rengger, on flies destroying cattle, 56.
Reproduction, rate of, 50.
Resemblance, protective, of insects, 181.
—, to parents in mongrels and hybrids, 260.
Reversion, law of inheritance, 11.
—, in pigeons, to blue colour, 127.
Rhododendron, sterility of, 239.
Richard, Prof., on Aspicarpa, 367.
Richardson, Sir J., on structure of squirrels, 139.
—, on fishes of the southern hemisphere, 338.
Robinia, grafts of, 246.
Rodents, blind, 110.
Rogers, Prof., Map of N. America, 274.
Rudimentary organs, 397.
Rudiments important for classification, 367.
Rütimeyer, on Indian cattle, 14, 241.
Sageret, on grafts, 246.
Salamandra atra, 397.
Saliva used in nests, 228.
Salmons, males fighting, and hooked jaws of, 69.
Salt-water, how far injurious to seeds, 325.
—, not destructive to land-shells, 353.
Salter, Mr., on early death of hybrid embryos, 249.
Salvin, Mr., on the beaks of ducks, 184.
Saurophagus sulphuratus, 141.
Schacht, Prof., on Phyllotaxy, 173.
Schiödte, on blind insects, 110.
Schlegel, on snakes, 115.
Schöbl, Dr., on the ears of mice, 172.
Scott, Mr. J., on the self-sterility of orchids, 238.
—, on the crossing of varieties of verbascum, 258.
Sea-water, how far injurious to seeds, 325.
—, not destructive to land-shells, 325.
Sebright, Sir J., on crossed animals, 15.
Sedgwick, Prof., on groups of species suddenly appearing, 282.
Seedlings destroyed by insects, 53.
Seeds, nutriment in, 60.
—, winged, 117.
—, power of resisting salt-water, 325.
—, in crops and intestines of birds, 326, 327.
—, eaten by fish, 327, 346.
—, in mud, 345.
—, hooked, on islands, 349.
Selection of domestic products, 22.
—, principle not of recent origin, 27.
—, unconscious, 27.
—, natural, 62.
—, sexual, 69.
—, objections to term, 63.
—, natural, has not induced sterility, 247.
Sexes, relations of, 69.
Sexual characters variable, 123.
—, selection, 69.
Sheep, Merino, their selection, 23.
—, two sub-breeds, unintentionally produced, 26.
—, mountain, varieties of, 59.
Shells, colours of, 107.
—, hinges of, 154.
—, littoral, seldom embedded, 270.
—, fresh-water, long retain the same forms, 308.
—, of Madeira, 349.
—, land, distribution of, 349.
—, land, resisting salt water, 325.
Shrew-mouse, 373.
Silene, infertility of crosses, 243.
Silliman, Prof., on blind rat, 110.
Sirenia, their affinities, 302.
Sitaris, metamorphosis of, 394.
Skulls of young mammals, 159, 384.
Smith, Col. Hamilton, on striped horses, 129.
Smith, Dr., on the Polyzoa, 193.
Smith, Mr. Fred., on slave-making ants, 217.
—, on neuter ants, 231.
Snake with tooth for cutting through egg-shell, 214.
Somerville, Lord, on selection of sheep, 23.
Sorbus, grafts of, 246.
Sorex, 373.
Spaniel, King Charles’ breed, 25.
Specialisation of organs, 98.
Species, polymorphic, 35.
—, dominant, 43.
—, common, variable, 42.
—, in large genera variable, 44.
—, groups of, suddenly appearing, 282, 285.
—, beneath Silurian formations, 287.
—, successively appearing, 290.
—, changing simultaneously throughout the world, 297.
Spencer, Lord, on increase in size of cattle, 26.
Spencer, Mr. Herbert, on the first steps in differentiation, 100.
—, on the tendency to an equilibrium in all forces, 252.
Sphex, parasitic, 216.
Spiders, development of, 390.
Sports in plants, 8.
Sprengel, C.C., on crossing, 76.
Squalodon, 302.
Squirrels, gradations in structure, 139.
Staffordshire, heath, changes in, 55.
Star fishes, eyes of, 144.
—, their pedicellariæ, 192.
Sterility from changed conditions of life, 7.
—, of hybrids, 236.
—, laws of, 241.
—, causes of, 247.
—, from unfavourable conditions, 250.
—, not induced through natural selection, 247.
St. Helena, productions of, 347.
St. Hilaire, Aug., on variability of certain plants, 174.
—, on classification, 368.
St. John, Mr., on habits of cats, 209.
Sting of bee, 163.
Stocks, aboriginal, of domestic animals, 14.
Strata, thickness of, in Britain, 268, 269.
Stripes on horses, 128.
Structure, degrees of utility of, 159.
Struggle for existence, 48.
Succession, geological, 290.
—, of types in same areas, 310.
Swallow, one species supplanting another, 59.
Swaysland, Mr., on earth adhering to the feet of migratory birds, 328.
Swifts, nests of, 228.
Swim-bladder, 148.
Switzerland, lake habitations of, 13.
System, natural, 364.
Tail of giraffe, 157.
—, of aquatic animals, 157.
—, prehensile, 188.
Tanais, dimorphic, 36.
Tarsi deficient, 108.
Tausch, Dr., on umbelliferæ, 173.
Teeth and hair correlated, 115.
—, rudimentary, in embryonic calf, 397, 420.
Tegetmeier, Mr., on cells of bees, 222, 226.
Temminck, on distribution aiding classification, 369.
Tendrils, their development, 196.
Thompson, Sir W., on the age of the habitable world, 286.
—, on the consolidation of the crust of the earth, 409.
Thouin, on grafts, 246.
Thrush, aquatic species of, 142.
—, mocking, of the Galapagos, 356.
—, young of, spotted, 388.
—, nest of, 234.
Thuret, M., on crossed fuci, 243.
Thwaites, Mr., on acclimatisation, 112.
Thylacinus, 374.
Tierra del Fuego, dogs of, 211.
—, plants of, 341.
Timber-drift, 326.
Time, lapse of, 266.
—, by itself not causing modification, 81.
Titmouse, 141.
Toads on islands, 350.
Tobacco, crossed varieties of, 258.
Tomes, Mr., on the distribution of bats, 351.
Transitions in varieties rare, 134.
Traquair, Dr., on flat-fish, 188.
Trautschold, on intermediate varieties, 275.
Trees on islands belong to peculiar orders, 350.
—, with separated sexes, 78.
Trifolium pratense, 57, 75.
—, incarnatum, 75.
Trigonia, 296.
Trilobites, 286.
—, sudden extinction of, 297.
Trimen, Mr., on imitating-insects, 377.
Trimorphism in plants, 35, 252.
Troglodytes, 234.
Tumbler pigeons, habits of, hereditary, 210.
—, young of, 392.
Turkey-cock, tuft of hair on breast, 70.
—, naked skin on head, 158.
—, young of, instinctively wild, 265.
Turnip and cabbage, analogous variations of, 125.
Type, unity of, 166, 167.
Types, succession of, in same areas, 310.
Typotherium, 302.
Udders enlarged by use, 8.
Ulex, young leaves of, 388.
Umbelliferæ, flowers and seeds of, 116.
—, outer and inner florets of, 173.
Unity of type, 166, 167.
Uria lacrymans, 72.
Use, effects of, under domestication, 8.
—, effects of, in a state of nature, 108.
Utility, how far important in the construction of each part, 159.
Valenciennes, on fresh-water fish, 344.
Variability of mongrels and hybrids, 259.
Variation, under domestication, 5.
—, caused by reproductive system being affected by conditions of life, 7.
—, under nature, 33.
—, laws of, 106.
Variations appear at corresponding ages, 10, 67.
—, analogous in distinct species, 124.
Varieties, natural, 32.
—, struggle between, 59.
—, domestic, extinction of, 86.
—, transitional, rarity of, 134.
—, when crossed, fertile, 257.
—, when crossed, sterile, 256.
—, classification of, 371.
Verbascum, sterility of, 238.
—, varieties of, crossed, 258.
Verlot, M., on double stocks, 230.
Verneuil, M. de, on the succession of species, 299.
Vibracula of the Polyzoa, 193.
Viola, small imperfect flowers of, 173.
—, tricolor, 57.
Virchow, on the structure of the crystalline lens, 145.
Virginia, pigs of, 66.
Volcanic islands, denudation of, 268.
Vulture, naked skin on head, 158.
Wading-birds, 375.
Wagner, Dr., on Cecidomyia, 387.
Wagner, Moritz, on the importance of isolation, 81.
Wallace, Mr., on origin of species, 1.
—, on the limit of variation under domestication, 31.
—, on dimorphic lepidoptera, 36, 232.
—, on races in the Malay Archipelago, 37.
—, on the improvement of the eye, 145.
—, on the walking-stick insect, 182.
—, on laws of geographical distribution, 322.
—, on the Malay Archipelago, 351.
—, on mimetic animals, 377.
Walsh, Mr. B.D., on phytophagic forms, 38.
—, on equal variability, 125.
Water, fresh, productions of, 343.
Water-hen, 143.
Waterhouse, Mr., on Australian marsupials, 90.
—, on greatly developed parts being variable, 119.
—, on the cells of bees, 220.
—, on general affinities, 379.
Water-ouzel, 142.
Watson, Mr. H.C., on range of varieties of British plants, 37, 46.
—, on acclimatisation, 112.
—, on flora of Azores, 328.
—, on rarity of intermediate varieties, 136.
—, on Alpine plants, 331.
—, on convergence, 100.
—, on the indefinite multiplication of species, 101.
Weale, Mr., on locusts transporting seeds, 327.
Web of feet in water-birds, 142.
Weismann, Prof., on the causes of variability, 6.
—, on rudimentary organs, 400.
West Indian islands, mammals of, 352.
Westwood, on species in large genera being closely allied to others, 45.
—, on the tarsi of Engidæ, 124.
—, on the antennæ of hymenopterous insects, 366.
Whales, 182.
Wheat, varieties of, 88.
White Mountains, flora of, 330.
Whittaker, Mr., on lines of escarpment, 267.
Wichura, Max, on hybrids, 249, 251, 260.
Wings, reduction of size, 109.
—, of insects homologous with branchiæ, 148.
—, rudimentary, in insects, 397.
Wolf crossed with dog, 210.
—, of Falkland Isles, 351.
Wollaston, Mr., on varieties of insects, 38.
—, on fossil varieties of shells in Madeira, 42.
—, on colours of insects on sea-shore, 107.
—, on wingless beetles, 109.
—, on rarity of intermediate varieties, 136.
—, on insular insects, 347.
—, on land-shells of Madeira naturalised, 357.
Wolves, varieties of, 71.
Woodcock with earth attached to leg, 328.
Woodpecker, habits of, 141.
—, green colour of, 158.
Woodward, Mr., on the duration of specific forms, 276.
—, on Pyrgoma, 284.
—, on the continuous succession of genera, 293.
—, on the succession of types, 311.
World, species changing simultaneously throughout, 297.
Wrens, nest of, 234.
Wright, Mr. Chauncey, on the giraffe, 178.
—, on abrupt modifications, 203.
Wyman, Prof., on correlation of colour and effects of poison, 9.
—, on the cells of the bee, 22.
Youatt, Mr., on selection, 23.
—, on sub-breeds of sheep, 26.
—, on rudimentary horns in young cattle, 400.
Zanthoxylon, 174.
Zebra, stripes on, 128.
Zeuglodon, 302.