On the Variation of Species, with Especial Reference to the Insecta / Followed by an Inquiry into the Nature of Genera

by Thomas Vernon Wollaston

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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].

FINIS.

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