The Project Gutenberg eBook of On The Variation Of Species, by T. Vernon Wollaston, M.A., F.L.S.

"Still changing, yet unchanged; still doom'd to feel
Endless mutation, in perpetual rest."

FOOTNOTES:

[84] Religion of Nature Delineated, p. 103.

[85] Vide supra, p. 128.

[86] Principles of Geology, 9th edition, pp. 583, 584.

[87] Vide supra, p. 121.

[88] Indications of the Creator (London, 1845), p. 163.

INDEX.

Aberration, perhaps indicated universally, 16, 17, 18.

Aborigines, insect, unimportant for climatal modifications, 25, 26, 27.

Acalles, the Canarian type of, apparent on the Salvages and Dezertas, 124.

—— Neptunus, Woll., perhaps a state of A. argillosus, 124.

Achatina Eulima, Lowe, its extinction in Porto Santo, 131.

Achenium Hartungii, Heer, a form of A. depressum, 65.

Acherontia Atropos, Linn., its introduction into Madeira perhaps recent, 74.

Adimonia, the capture of, out at sea, 150.

Aëpus marinus, Ström., pallid hue of, 64.

—— Robinii, Lab., pallid hue of, 64.

Agabus bipustulatus, Linn., unaffected by climate, 31.

Alligators, their peculiarity to S. America, 143.

Alpine species, some peculiarly so, 40.

Altitude and latitude, sometimes reciprocal, 35, 114.

Amyeterus, its concentration in Australia, 143.

Amyot, M., his 'Méthode Mononomique,' 164.

Analogies, Lord Bacon on the importance of, 13;

why necessary to be studied, 14.

Analogy, argument from, 10, 11, 12.

Anchomenus marginatus, Linn., slightly modified in Madeira, 38.

Andes, dissimilarity of the fauna on the opposite sides of the, 146.

Anobium striatum, Oliv., unaffected by climate, 31.

Antennæ, joints of, said occasionally to vary, 96.

Anthicus bimaculatus, Illig., variability of, near the sea, 63.

—— fenestratus, Schmidt, slightly modified in Madeira, 38.

—— humilis, Germ., variability of in salt places, 63.

—— instabilis, Hoffm., pallid hue of, 64.

Anthonomus ater, Mshm, very small in Lundy Island, 58, 73.

Aphelocheirus æstivalis, Fabr., the hemelytra of, sometimes fully developed, 100.

Aphodius nitidulus, Fabr., paler in Madeira than in Europe generally, 65.

Aphodius plagiatus, Linn., usually black in England, 61;

two distinct states of, indicated, 105.

Apocyrtus, its concentration in the Philippine Islands, 143.

Apotomus, common to Madeira and Sicily, 139.

Argutor, always apterous in Madeira, 82;

trophi of, almost identical with those of Calathus, 175.

Armadillos, their peculiarity to S. America, 143.

Armitage, Mr., on Cicindela fasciatopunctata from Mount Olympus, 41.

Arrangement, a lineal one is not indicated in Nature, 163.

Atlantic continent, Prof. E. Forbes on the former existence of, 137.

Atlantis of the ancients, the impossibility of its being identified with a former Atlantic region, 140;

perhaps the New World, 141.

Atlantis, the genus, a modification of Laparocerus, 143.

Azores, the colonization of, by two Madeiran Helices, 133.

Bacon, Lord, on the importance of analogies, 13;

on the Atlantis of the ancients, 141;

on the necessity of observation for forming science, 159.

Banksias, their concentration in Australia, 142.

Barriers, natural, the difference between primary and recent, 145;

their hindrance to insect diffusion, 145.

Bembidium Atlanticum, Woll., paler in Porto Santo than in Madeira, 66;

the variations to which it is subject, 107, 108.

—— bistriatum, Dufts., paler in saline districts, 62.

—— ephippium, Mshm, pallid hue of, 64.

—— obtusum, Sturm, varies in southern latitudes, 33.

—— pallidipenne, Illig., pallid hue of, 64.

—— saxatile, Gyll., variety of, on the south coast of England, 60.

—— Schmidtii, Woll., perhaps a state of B. callosum, 66.

—— scutellare, Germ., pallid hue of, 64.

—— tabellatum, Woll., perhaps a state of B. tibiale, 66.

Berginus, common to Madeira and Sicily, 139.

Black Rat, nearly exterminated in England, 178.

Blemus areolatus, Creutz., paler in brackish places, 62.

Bolitochara assimilis, Kby, smallness of, in the Scilly Islands, 73.

Boromorphus, common to Madeira and Sicily, 139.

Brachinus crepitans, Linn., two distinct sizes of, frequently indicated, 105.

Bradycellus fulvus, Mshm, apterous in Madeira, 85.

Bread-fruit Trees, their peculiarity to the South Sea Islands, 142.

Calathus, apterous in Madeira, 82; its trophi almost identical with those of Pristonychus, 175.

—— complanatus, Koll., varies from altitude, 39;

variety of, on one of the Madeira Islands, 88.

—— fuscus, Fabr., slightly modified in Madeira, 38, 85.

Calathus melanocephalus, Linn., smallness of, in the Scilly Islands, 73.

—— mollis, Mshm, variable in its wings, 43;

lurid colour of, 64.

Calcareous soils, effect of, on the aspect of insects, 66.

Calceolarias, their concentration on the Andes, 142.

Calosoma, a species of, ten miles from shore, 147;

the genus, mergescgradually into Carabus, 175.

—— Syncophanta, Linn., its power of crossing the sea, 147.

Canary Islands, migratory direction of their insect population, 119.

Carabidæ, inconstant in their organs of flight, 43;

family of, nearly similar throughout in its oral organs, 174.

Carpophilus hemipterus, Linn., unaffected by climate, 31.

Caulotrupis conicollis, Woll., large size of, on one of the Madeira Islands, 88, 109.

—— lucifugus, Woll., varies from isolation, 90, 109.

Causes, never final ones which we investigate, 191.

Centrinus, its concentration in S. America, 143.

Ceutorhynchus contractus, Mshm, smallness of, in Lundy Island, 59, 73.

Cholovocera, common to Madeira and Sicily, 139.

Choreius ineptus, Westw., on a winged state of, 44.

Chorosoma miriforme, the development of the wings of, 100.

Chrysomela, apterous in Madeira, 82.

Chrysomelæ, vary from altitude, 41.

Chrysomelidæ, almost absent in Tierra del Fuego, 47.

Cicindela fasciatopunctata, Germ., a state of C. sylvatica 41.

Cicindelidæ, often variable, 41.

Cillenum laterale, Sam., lurid hue of, 64.

Cimex apterus, Linn., the development of the wings of, 100.

—— lectularius, Linn., on the development of the wings of, 45.

Cistela sulphurea, Linn., its variability near the sea, 60.

Clausilia deltostoma, Lowe, a Porto-Santan form of, 134.

Climatal modifications significant, although small, 42.

Climate, not important as a disturbing cause, 23, 24, 31, 32, 42.

Clouded-yellow Butterfly, unaffected by climate, 31.

Clypeaster pusillus, Gyll., differs slightly in Madeira, 65.

Coast, inconstancy of insects in the vicinity of the, 57.

Coccinella 7-punctata, Linn., unaffected by climate, 31.

Colias Edusa, Fabr., unaffected by climate, 31.

Colour, its inconstancy in insects found near the sea, 57, 58.

—— of insects, affected by isolation, 88.

Colymbetes, a species of, captured forty-five miles from shore, 149, 150.

Compensation, generally apparent when an insect is deprived of an organ or sense, 81.

Coranus subapterus, Curt., the development of the wings of, 101.

Cordillera, Mr. Darwin on the fauna of the, 145.

Corylophus, apterous in Madeira, 82.

Criomorphus, Curtis, referable to the genus Delphax, 45.

Cyclostoma lucidum, Lowe, its extinction in Porto Santo, 131.

Cynthia Cardui, Linn., unaffected by climate, 32.

Cynucus, a species of, seventeen miles from shore, 150.

Cyrtonota, its concentration in S. America, 143.

Darwin, Mr., on the fauna of the Galapagos, 23;

relative proportions of the insect tribes in the tropics, 28, 29;

on the insects of Tierra del Fuego, 47;

on the natural features of Tierra del Fuego, 50;

on the insects of Keeling Island, 55;

on the insects of St. Helena, 55;

on the insects of Ascension, 55;

on the apterous condition of insular species, 86;

on the fauna of the Cordillera, 145;

on a Calosoma captured at sea, 147;

on insects captured in the sea, 149, 150;

on the disappearance of animals before more powerful ones than themselves, 178.

Dawson, Rev. J. F., on a variety of Bembidium saxatile, 60.

Definition of the term 'species,' 4;

of the term 'variety,' 4.

Delphax, on the development of the wings of, 45.

Dermestes vulpinus, Fabr., unaffected by climate, 31.

Deucalion, its occurrence on the Salvages and Dezertas, 125.

—— Desertarum, Woll., its sedentary nature, 125, 126, 127.

Dichelus, its concentration in S. Africa, 143.

Differences, when to be regarded as specific, 6;

too exclusively studied, 12.

Diffusion, various means of, which operate on the insect tribes, 148.

Disturbing agents, Prof. Henfrey on, 8.

Ditylus, the same type of, indicated in the Canaries and Salvages, 124.

Domesticated animals, pliable nature of, 187, 192.

Dromius arenicola, Woll., representative of D. obscuroguttatus, 66.

—— fasciatus, Gyll., its paleness near the sea, 63.

—— negrita, Woll., perhaps an ultimate state of D. glabratus, 85.

—— obscuroguttatus, Dufts., its changes in Madeira, 36, 37, 38;

apterous in Madeira, 84.

—— sigma, Rossi, its colour affected by isolation, 88, 89.

Elevation, sometimes corresponds with latitude, 35, 114.

Ellipsodes glabratus, Fabr., singular variety of, on one of the Madeira Islands, 88, 109.

Elytra, connateness of, a variable character, 96.

'Endemic,' to what species the term is applicable, 118.

Entomology, the study of, does not necessarily cramp the mind, 111.

Ephistemus, apterous in Madeira, 82.

Eucalypti, their concentration in Australia, 142.

Eunectes sticticus, Linn., unaffected by climate, 31.

Euphorbias, their concentration in Southern Africa, 142.

Eurygnathus Latreillei, Lap., variety of, on one of the Madeira Islands, 88, 109.

Exceptions, not be allowed to negative a law, 72, 73.

Extinction of species, as indicated in the Madeiran Helices, 131;

the only cause by which genera may be abruptly defined, 176.

Forbes, Prof. E., on the origin of the British animals and plants, 130;

his epochs of migration of the British animals and plants, 136;

on the existence of a former Atlantic continent, 137.

Forests, the hindrance which they offer to insect-diffusion, 154.

"Fortunate Islands" of the ancients, probably the Canarian group, 141.

Galapagos, fauna of, 23.

Genera, the nature of, often misunderstood, 160;

a familiar explanation of, 160, 161, 162;

cannot be abrupt except from accident, 169;

how to be defined, 169;

the types of, usually situated towards the centres of the several groups, 170;

the types of, usually evenly balanced in their structural characters, 171, 172;

may be abruptly defined from accidental causes, 176, 177.

Generic areas, an important feature throughout Nature, 130, 141, 184.

Geology, a necessary item in the study of insect-diffusion, 113.

Germanic plains, the, probably a primary area of diffusion, 130.

Gerris, on the development of the wings of, 100.

Gould, Mr., on the Swallows of Malta, 102.

Gymnaëtron, blood-red dashes characteristic of, 62.

—— Campanulæ, Linn., its smallness on the Cornish coast, 58.

—— Veronicæ, Germ., a variety of G. niger, 62.

Hadrus illotus, Woll., perhaps a form of H. cinerascens, 66.

Haliplus obliquus, Gyll., dark state of, in Ireland, 67.

Haltica exoleta, Fabr., its variability on the coast, 59.

Harcourt, Mr., on the discovery of Madeira, 49, 50.

Harpalus vividus, Dej., changes to which it is subject, 67, 68, 69;

variable in the connateness of its elytra, 96, 97.

Hegeter, its maximum attained in the Canaries, 120.

—— elongatus, Oliv., its migration from the Canaries, 120;

of a more adaptive nature than its allies, 121.

—— latebricola, Woll., its occurrence in the Salvages, 120.

Helices, have often two distinct states, 106;

many of them representative in the Madeira Islands, 128, 129;

those in the Madeiras chiefly of slow migratory powers, 130, 131.

Helix attrita, Lowe, its local character, 132.

—— Bowdichiana, Fér., perhaps a gigantic state of H. punctulata, 106.

—— calculus, Lowe, sedentary nature of, 132.

Helix commixta, Lowe, sedentary nature of, 132.

—— coronata, Desh., its peculiarity to Porto Santo, 128;

its occurrence beneath the surface of the ground, 131.

—— coronula, Lowe, its peculiarity to the Southern Dezerta, 128.

—— Delphinula, Lowe, the Madeiran representative of H. tectiformis in Porto Santo, 129.

—— discina, Lowe, a form of H. polymorpha, 133.

—— erubescens, Lowe, its powers of diffusion greater than those of its allies, 133;

sensitive to external influences, 134.

—— fluctuosa, Lowe, its extinction in Porto Santo, 131.

—— hirsuta, Say, two distinct states of, 106.

—— lapicida, Linn., its extinction in Porto Santo, 131.

—— latens, Lowe, the Madeiran representative of H. obtecta in Porto Santo, 129.

—— lincta, Lowe, the common Madeiran form of H. polymorpha, 134.

—— Lowei, Pfr., perhaps a gigantic state of H. Portosanctana, 106.

—— papilio, Lowe, a form of H. polymorpha, 133.

—— paupercula, Lowe, its powers of diffusion greater than those of its allies, 133.

—— polymorpha, Lowe, sensitive to external influences, and of great diffusive powers, 133.

—— Portosanctana, Sow., its peculiarity to Porto Santo, 129.

—— pulvinata, Lowe, a form of H. polymorpha, 133.

—— saccharata, Lowe, a local state of H. polymorpha, 134.

—— senilis, Lowe, the Dezertan form of H. polymorpha, 134.

—— squalida, Lowe, the Madeiran representative of H. depauperata in Porto Santo, 129.

—— tiarella, Webb, its sedentary nature, 128.

—— undata, Lowe, its peculiarity to Madeira proper, 129.

—— Vulcania, Lowe, its peculiarity to the Dezertas, 129.

—— Wollastoni, Lowe, sedentary nature of, 132.

Helobia nivalis, Payk., perhaps a state of H. brevicollis, 40.

Helops, always apterous in Madeira, 82.

—— confertus, Woll., varies from altitude, 39.

—— futilis, Woll., varies from isolation, 109.

—— testaceus, Küst., pallid hue of, 64.

—— Vulcanus, Woll., large size of, on one of the Madeira Islands, 88.

Henfrey, Prof., on disturbing agents, 8.

Herschel, Sir John, on the requisites for an observer, 12.

Hipparchia Semele, Linn., has a distinct aspect in Madeira, 34.

Hipporhinus, its concentration in S. Africa, 143.

Holme, Mr., on Olisthopus rotundatus in the Scilly Islands, 58, 102;

on a winged state of Phosphuga atrata, 102.

Holoparamecus, common to Madeira and Sicily, 139.

—— Niger, Aubé, different in Madeira and Sicily, 33.

Hooker, Dr., on the insects of Kerguelen's Land, 86.

Humboldt, his notice of Sphinxes and flies high up on the Andes, 149.

Humming-Birds, their peculiarity to S. America and the W. Indies, 142.

Hydrobius, apterous in Madeira, 82;

the capture of, out at sea, 150.

Hydrometridæ, on the development of the wings of, 100.

Hydroporus, the capture of, out at sea, 150.

—— confluens, Fabr., unaffected by climate, 31.

Hypsonotus, its concentration in S. America, 143.

Influence of climate not important, 23.

Insect-aberration, perhaps a universal fact, 16, 17, 18.

Insulæ Fortunatæ of Juba, probably the Canarian Group, 141.

Ireland, poverty of the fauna of, 52, 53;

the south-west of, has something in common with Madeira, 139.

Islands, faunas of, often too greatly magnified, 70;

the species of, generally more isolated in their structure than those of continents, 177.

Isolation, effects of, on insect-stature, 71.

Ixias, their concentration in Southern Africa, 142.

Kangaroos, their concentration in Australia, 142.

Kerguelen's Land, insects of, 86.

Kirby, Rev. W., on insects washed up on the Suffolk coast, 147.

Læmophlœus pusillus, Schönh., unaffected by climate, 31.

Lamprias chlorocephalus, Ent. H., two distinct sizes of, frequently indicated, 105.

Laparocerus morio, Schönh., large size of, on one of the Madeira Islands, 88.

Latitude and altitude, sometimes reciprocal, 35.

Leistus montanus, Steph., has been supposed to be equal to L. fulvibarbis, 40.

Lemur, its peculiarity to Madagascar, 143.

Litargus, common to Madeira and Sicily, 139.

Lixus angustatus, Fabr., unaffected by climate, 31.

Localities, some naturally more productive than others, 53, 54.

Longitarsus, the native species of, apterous in Madeira, 82.

Loricera, apterous in Madeira, 82.

Lowe, Rev. R. T., his capture of the Deucalion Desertarum, 127.

Lundy Island, smallness of the insects in, 58, 59;

occurrence of the Black Rat in, 178.

Lycæna Phlœas, Linn., darker in Madeira than in England, 34.

Lyell, Sir Charles, on Helix hirsuta, 106;

on the fossil period of the Madeiran Helices, 129;

on insects washed up on the shore, 148;

on the effect of gales in the transportation of insects, 148;

on the effects of a volcanic eruption in destroying species, 179;

on the flexible nature of certain animals and plants, 187;

on the greater differences which varieties often present than do species, 193.

Lygæus brevipennis, Latr., on the development of the wings of, 101.

Macronota, its peculiarity to Java, 143.

Madeira, has some features in common with Tierra del Fuego, 48, 49, 50, 51;

former state of, 48, 49;

great fire on the southern side of, 49;

origin of the name of, 50; the insects of, 55;

the tendency of its insects to become apterous, 82;

the migratory direction of its insect population, 119;

the local nature of its various species, 152, 153.

Magnolias, their concentration in Central America, 142.

Malta, Mr. Gould on the birds of, 102.

Malthodes Kiesenwetteri, Woll., perhaps a state of M. brevicollis, 66.

Man, agency of, in the destruction of species, 179.

Mantura Chrysanthemi, Ent. H., variability of, in Lundy Island, 59.

Marsupialia, their concentration in Australia, 142.

Mesembryanthemums, their concentration in Southern Africa, 142.

Mesites, a modification of Cossonus, 144.

—— Maderensis, Woll., its near relationship to the M. Tardii, 141.

—— Tardii, Curtis, its variability near the coast, 58.

'Méthode Mononomique,' the unsoundness of, 164-168.

Migratory powers, slowness of, in the Madeiran Helices, 130-132.

—— progress, direction of, in the Madeiran animals, 120, 135.

Mimosas, their concentration in Australia, 142.

Mollusca, Terrestrial, often present two distinct states, 106.

Moluris, its concentration in S. Africa, 143.

Monochelus, its concentration in S. Africa, 143.

Mountain-chains, their hindrance to insect-diffusion, 145.

Mountain-tops, either very prolific in insect life, or else barren, 115.

Mus Rattus, almost exterminated in England, 178.

Mycetoporus pronus, Erichs., two distinct states of, indicated, 106.

Myrtles, their concentration in Australia, 142.

Naturalist, the, what his province to investigate, 158.

Nature, not irregular because presenting occasional anomalies, 94.

Naupactus, its concentration in S. America, 143.

Nebria complanata, Linn., unusually pale near Bordeaux, 33;

pallid hue of, 64.

New World, some of its insects perhaps but states of those of the Old, 37.

Nomenclature, a binomial system the only true one, 164, 168.

Notaphus, the capture of, out at sea, 150.

Notiophili, extremely variable, 40.

Notiophilus geminatus, Dej., large size of, on one of the Madeira Islands, 88.

Observation, indispensable in natural science, 20, 159, 192.

Ocean, the, its hindrance to insect-diffusion, 145.

Ochthebius marinus, Payk., lurid hue of, 64.

Olisthopus, apterous in Madeira, 82.

—— Maderensis, Woll., large state of, on one of the Madeira Islands, 88, 89.

—— rotundatus, Payk., very small in the Scilly Islands, 58, 73;

subapterous in the Scilly Islands, 102.

Omaseus nigerrimus, Dej., a form of O. aterrimus, 33.

Omias Waterhousei, Woll., large state of, on one of the Madeira Islands, 88, 109.

Oncocephalus griseus, development of the wings of, 101.

Othius, apterous in Madeira, 82.

Ourangs, their peculiarity to the Indian Islands, 143.

Oxyomus, a modification of Aphodius, 144.

Pachymerus brevipennis, the development of the wings of, 100.

Pachyrhynchus, its concentration in the Philippine islands, 143.

Painted-Lady Butterfly, unaffected by climate, 32.

Papilio Machaon, Linn., unaffected by climate, 31.

Paropsis, its concentration in Australia, 143.

Patagonia, insects of, distinct from those of Tierra del Fuego, 47, 48.

Patrobus septentrionis, Dej., has been supposed to be a state of P. excavatus, 40.

Pecteropus, its maximum attained in the Canaries, 124.

—— Maderensis, Woll., varies from altitude, 39.

—— rostratus, Woll., varies from isolation, 90.

Pelargoniums, their concentration in Southern Africa, 142.

Pelophila borealis, Payk., larger in Ireland than in the Orkneys, 33.

Phaleria cadaverina, Fabr., pallid hue of, 64.

Philhydrus melanocephalus, Oliv., two states of, frequently indicated, 105.

Phlæophagus, apterous in Madeira, 82.

Phosphuga atrata, Linn., taken with the wings developed, 102.

—— subrotundata, Leach, the Irish form of the P. atrata, 33.

Phytophaga, preponderance of, in the tropics, 28, 29.

Pieris Brassicæ, Linn., varies in Nepaul and Japan, 34.

Pissodes notatus, Fabr., unaffected by climate, 30.

Platyomus, its concentration in S. America, 143.

Platyrrhini, their peculiarity to S. America, 143.

Pogonus luridipennis, Germ., lurid hue of, 64.

Pontia Brassicæ, Linn., its introduction into Madeira probably recent, 74.

Porto Santo, origin of the name of, 49;

a generic area of radiation for certain Helices, 130.

Predacious insects, less numerous in the tropics, 28, 29.

Prostemma guttula, Fabr., the development of the wings of, 100, 101.

Psylliodes, a variable species of, in Lundy Island, 60.

—— erythrocephala, Linn., two distinct states of, frequently indicated, 105.

—— marcida, Illig., pallid hue of, 64.

—— nigricollis, Mshm, a pale state of the P. erythrocephala, 105.

—— vehemens, Woll., varies from isolation, 90.

Pterostichus, its various divisions are natural ones, 175.

Ptini, their stature affected by isolation, 74;

which characters of, are the most constant, 104.

Ptinus albopictus, Woll., its changes on the islands of the Madeiran Group, 75-77.

Pupa, often two distinct states of, 106.

Purpurariæ of the ancients, probably the Madeiran Group, 141.

Pyrenean region, the, perhaps a primary area of diffusion, 130.

Reasoning, not sufficient of itself for the formation of science, 159.

Red-Admiral Butterfly, its introduction into Madeira perhaps recent, 74.

Reduviadæ, on the development of the wings of a representative of the, 101.

Representative species, exemplified by the Madeiran Helices, 128, 129, 185;

where frequently to be recognized, 183.

Rhyzopertha pusilla, Fabr., unaffected by climate, 31.

Rivers, their power of transporting insects along their course, 149.

Saline spots, variation of insects in, 57.

Salvages, occurrence of a Canarian form on the, 120, 124.

Saprinus, a modification of Hister proper, 143.

—— nitidulus, Fabr., two distinct states of, indicated, 106.

Scarabæus, the capture of, out at sea, 150.

Scarites abbreviatus, Koll., large size of, on one of the Madeira Islands, 88;

varies both from isolation and altitude, 91.

Sciences, the, should assist rather than oppose each other, 155, 156.

Scydmænus Helferi, Schaum, smaller in Madeira than in Sicily, 65.

Scymnus, an apterous species of, in Porto Santo, 82.

Sea, inconstancy of insects in the vicinity of the, 57.

Sicily, the fauna of, has much in common with that of Madeira, 139.

Silpha atrata, Linn., presents a distinct state in Ireland, 33.

Silybum Marianum, Grtn., its stalks the food of a Ptinus, 76.

Similitudes, Lord Bacon on the importance of, 13.

Sitonia gressoria, Illig., perhaps a form of the S. grisea, 33.

Sitophilus granarius, Linn., unaffected by climate, 31.

Sitophilus oryzæ, Linn., unaffected by climate, 31.

Sloths, their peculiarity to S. America, 143.

Species, definition of the term, 4;

familiar explanation concerning the nature of, 161, 162;

limitation of, how to be attempted, 192;

limits of, real, though often difficult to trace out, 193;

in a certain sense both unstable and permanent, 194.

Specific centres of creation, 5.

Sphinx Convolvuli, Linn., its introduction into Madeira probably recent, 74.

Spinola, on one of the Reduviadæ, 101;

on Oncocephalus griseus, 101.

Stapelias, their concentration in Southern Africa, 142.

States, large and small ones indicated in some insects, 105.

Stature of insects, smaller in islands than on continents, 70.

Stenolophus Skrimshiranus, Steph., perhaps a state of S. Teutonus, 63.

Stenus Heeri, Woll., two distinct states of, indicated, 106.

Structural characters, seldom variable in the Insecta, 95.

Subsidences, the effect of, on insect life, 114.

Swallow-Tail Butterfly, unaffected by climate, 31.

Syncalypta, apterous in Madeira, 82.

Tachyporus nitidicollis, Steph., perhaps a state of T. obtusus, 33.

Tarphii, their economy in the Madeira Group, 121.

Tarphius, its maximum attained in Madeira proper, 121;

common to Madeira and Sicily, 139.

—— gibbulus, Germ., the Sicilian exponent of the genus, 123.

—— Lowei, Woll., of a more adaptive nature than its allies, 122.

Tarus, always apterous in Madeira, 82.

—— lineatus, Schönh., assumes a distinct state in Madeira, 65.

Telephorus testaceus, Linn., its variability in Lundy Island, 59.

Thompson, Mr., on the reptiles of Ireland, England, and Belgium, 136.

Thorictus, common to Madeira and Sicily, 139.

Tierra del Fuego, insects of, 47;

has many characters in common with Madeira, 48-51.

Time, an important item in the question of modifications, 77.

Toucans, their peculiarity to S. America and the W. Indies, 142.

Transmutation-theory, unsoundness of the, 186-189;

how it took its rise, 190.

Trechus, always apterous in Madeira, 82.

—— alticola, Woll., perhaps a state of T. custos, 39.

—— lapidosus, Daws., pallid hue of, 64.

Tree-Porcupines, their peculiarity to S. America, 143.

Tribolium ferrugineum, Fabr., unaffected by climate, 31.

Trogosita mauritanica, Linn., unaffected by climate, 31.

Tropics, exuberance of the, 27, 28;>

relative proportions of the insect tribes within the, 28, 29.

Tychius, always apterous in Madeira, 82.

Unity, indicated in the organic creation, 179, 180.

Vanessa Atalanta, Linn., has a different aspect in N. America, 34;

perhaps a recent introduction into Madeira, 74.

—— Callirhoë, Fabr., smaller in Porto Santo than in Madeira, 73.

Variation in the Insecta, a matter of experience, 7, 8, 15;

probable from analogy, 15;

perhaps indicated in every individual, 16, 17, 18;

restricted, 35.

Variety, definition of the term, 4.

Velia, on the development of the wings of, 100.

Waterhouse, Mr., his opinion concerning generic types, 172.

Westwood, Mr., on Papilio Machaon from the Himalayas, 32;

on American specimens of Lycæna Phlœas, 34;

on the effect of heat in developing the wings of insects, 44;

on a winged state of Choreius ineptus, 44;

on the development of the wings in Delphax, 45;

on a winged state of Cimex lectularius, 45;

on Aphelocheirus æstivalis, 100;

on the development of the wings of the Hydrometridæ, 100;

on Cimex apterus, 100;

on Prostemma guttala and Coranus subapteras, 101;

on the development of the wings of Lygæus brevipennis, 101.

Whewell, Dr., on the natural causes which science has to investigate, 191.

White-Cabbage Butterfly, varies in Nepaul and Japan, 34.

Winds, the effects of, in the diffusion of insects, 148.

Wings of insects, subject to undue development in hot seasons, 43;

liable to become gradually obsolete in islands, 81;

more variable than other organs, 97.

Xenostrongylus, its geographical distribution, 124;

common to Madeira and Sicily, 139.

Zargus pellucidus, Woll., variety of, on one of the Madeira Islands, 88.