Part 21

_Araschnia._ _A. levana_ and _A. prorsa_ seasonally dimorphic, 2; dimorphism of larvæ, 6; _A. levana_, first experiments with, 10; _A. var. porima_, artificial production of, 10, 17; _A. levana_, Dorfmeister’s experiments with, 11; explanation of seasonal dimorphism of, 19; northern, extension of, 20; _A. prorsa_ gradual origination of, 22; _A. levana_, reversion of, caused by high temperature, 37; the _levana_ form the most constant, 43, and sexually dimorphic, 43; summer and winter forms compared, 56; experiments with _A. levana_, 117; _A. levana_, variable in all three stages, 405; incongruence in genus, 449.

Argent, W. J., phytophagic variability of larva of _Sphinx Ligustri_, 306.

_Argynnis paphia_, dimorphism of, 250.

_Artemia salina_ and _A. Milhausenii_, transformations of, 635.

_Ascaris nigrovenosa_, propagation of, 90.

Askenasy, on limits of variability, 114.

Atavism and arrested growth, 587.

_Aterica meleagris_, colour variations of, 8.

Atoms, actions of, 710; sensibility of, 714.

Axolotl, transformation into Amblystoma, 555; experiments with, 558; duration of transformation, 563; conditions of metamorphosis of, 564; distinguishing characters, 575.

B.

Baer, Karl Ernst von, on the mechanism of nature, 639; on the vital force, 641; on the theory of selection, 694; on causality and purpose, 708.

Baird, Prof., on the development of species of _Amblystoma_, 623.

Balbiani, reproduction of Aphides, 97.

Balfour, F. M., on insect phylogeny, 485, 494.

Bates, H. W., local variation in Amazonian Lepidoptera, 60.

Bees, embryological development of, 483.

Belt, Thomas, on coloured frogs, 294; on the glaciation of North America, 622.

Biogenetic law, corollary of, 611.

Birchall, E., local variation in British Lepidoptera, 60.

Blanchard, on oviposition of _Amblystoma_, 594.

Boisduval, figures of larvæ referred to, 216, 218, 245; on snake-like appearance of the larva of _D. nicæa_, 342; on the relationship of _Euchloe belia_ and _E. ausonia_, 48.

_Bombycidæ_, early stage of larvæ, 166.

_Bombyx._ _B. cynthia_, colour changes in larva, 7; _B. neustria_, caterpillar refused by lizards, 336; _B. Rubi_, caterpillar eaten by lizards, 338.

Boscher, E., dimorphism of larva of _S. ocellatus_, 241, 306.

Brauer, insect phylogeny, 493.

Burmeister, figures of larvæ referred to, 195, 196, 224, 232, 255, 261, 263, 436, 437; early stages of larvæ of Argentine butterflies, 166.

Butler, A. G., affinities of genus _Acronycta_, 169; genera of _Chærocampinæ_, 190, 192, 194, 196; genera of _Smerinthinæ_, 233, 243, 244; genera of _Macroglossinæ_, 253, 254; species of _Pterogon_, 256; genera of _Sphinginæ_ and _Acherontiinæ_, 262; on coloured larvæ being rejected, 336; affinities of _Sesiidæ_, 370; descriptions and figures of new Sphinx-larvæ, 524, 526.

Bütschli, embryology of bees, 483.

Butterflies, action of warmth in producing changes in colour and marking, 58; summer and winter larvæ and pupæ alike in seasonally dimorphic species, 64; seasonally dimorphic species hibernate as pupæ, 73; odoriferous organs, 102; early stages of larvæ, 165; di- and polymorphism of, 250; crepuscular habits of certain species, 475.

C.

_Callosune eupompe_, polymorphism of female, 251.

Cameron, P., on larva of _S. ocellatus_, 241, 282; protective habits of saw-fly larvæ, 290, 294.

Carlin, W. E., on _Siredon lichenoides_, 630.

Caterpillars, origin of markings, 161; means of defence, 289; defensive habits, 290; food of brightly coloured species, 294; habit of concealment by day, 291, 296; phytophagic variability, 305, 531; seasonal variability, 305; experiments with ocellated species, 330; experiments with annulated species, 336; sexual dimorphism of, 308, 527, 534; independent variability of stages, 416.

_Cecidomyia_, metagenesis of, 82, 586.

_Chærocampa._ _C. elpenor_ and _C. porcellus_, relationship of, 171; markings of larvæ of the genus, 177; _C. elpenor_, 1st and 2nd larval stages, 178; 3rd and 4th stages, 180; 5th stage, 181; 6th stage, 183; _C. porcellus_, 1st larval stage, 184; 2nd and 3rd stages, 185; 4th stage, 186; _C. elpenor_ and _porcellus_, larval markings compared with other species of _Chærocampa_, 188; _C. elpenor_, experiments with larva, 331, 332; _C. Japonica_ and _C. Lewisii_, larvæ, 194; _C. cretica_, larva, 524; _C. lycetus_, larva, 527; _C. capensis_, larva, 529; eaten by birds, &c., 530.

Characters, new, backward transference of, 279.

Chauvin, Fräulein von, experiments with Axolotl, 558; experiments with _Salamandra atra_, 615.

Chavannes, figure of larva referred to, 255.

Clarke, development of _Amblystoma punctatum_, 623.

Classification, objects of, 168.

Claus, on the origination of heterogenesis, 89.

Clemens, larva of _A. ello_, 268.

Climatic variation, 45; in _P. Napi_, 47; in _E. Belia_, 47; nature of causes producing, 52, 105; by sex, 61, 62; climatic varieties very distinct from local, 45; climatic influences operate slowly, 58; climatic changes gradual, 652, 660.

Cole, B. G., seasonal dimorphism of _E. punctaria_, 4.

Coleoptera, grub-like larvæ of, 495.

_Colias edusa_, dimorphism of female, 250.

Colour, biological value of, 289.

Conditions of life, compulsory changes in, 651.

Congruence in Lepidopterous families, 435; in Lepidopterous genera, 444.

_Coniferæ_, food-plants of _Anceryx_, 268.

Convergence of characters in _Ophiuroidea_, 396; in Dipterous larvæ, 494.

Cope, Prof., habits of _Siredon Mexicanus_, 566; on distribution of _Amblystoma_, 569.

Correlation of growth, 278, 363, 388, 415; action of, 415, 516; Von Hartmann’s views of, 670; nature of, 673.

_Cryptobranchus_, characters of, 579.

Cyclical propagation, 82, 699; and reversion, 613.

D.

Daphniacea, differences between allied species and genera, 516.

Darwin, C., influence of external conditions of life, 59; inheritance at corresponding periods, 63, 275, 431; markings of butterflies, 101; definition of eye-spots, 326; adaptation in larvæ, 392; correlation of growth, 516; degeneration, 583; adaptation, 589; causes of sterility, 596; limited variability, 656; factors of variability, 676; abrupt variations, 701.

Degeneration, 583; phyletic, 611.

_Deilephila_, division of larvæ into groups, 199; _D. Euphorbiæ_, 1st larval stage, 202; 2nd and 3rd stages, 203; 4th and 5th stages, 205; _D. nicæa_, larva, 207; _D. dahlii_, larva, 208; _D. vespertilio_, larva, 209; _D. Galii_, larva, 211; 5th stage, 213; _D. livornica_, larva, 215; _D. Zygophylli_, larva, 217; _D. Hippophaës_, larva, 218, 650; division of larvæ according to phyletic stages, 223; genealogy of, 358; _D. Galii_, larva rejected, 340; _D. Euphorbia_, larva eaten, 340; habits of larvæ and imagines, 412; _D. Robertsi_, larva, 525.

Development; of marking of Sphinx-larvæ, laws of, 274; phyletic, of markings of _Sphingidæ_, 370; unequal phyletic, 460.

Dimorphism and polymorphism; of butterflies, 250; of Sphinx-larvæ, 300; of pupæ, 412.

Diptera, incongruences among, 488; imaginal characters of, 488; divisions of, 498.

Dodo, extinction of, 651.

Dohrn, A.; on degeneration, 583; on functional change, 590.

Dorfmeister, G.; experiments with _A. levana_, 11.

Duponchel; figures of larvæ referred to, 207, 208, 218, 253.

Duméril; experiments with Axolotl, 555, 564, 566, 593; characters of Axolotl, 375, 576.

E.

Edwards, W. H., seasonal dimorphism of _P. pseudargiolus_ and _P. violecea_, 4; of _P. Tharos_ and _P. Marcia_, 4; of _P. Ajax_, 30; of _L. Artemis_ and _L. Proserpina_, 32; experiments with _P. Ajax_ and _P. Tharos_, 33, 126, 140; pupal period of winter forms of _P. Ajax_, 36; experiments with _G. interrogationis_, 149; early stages of larvæ of N. American butterflies, 165; larva of _P. pseudargiolus_ and attendant ants, 290; figures of larvæ referred to, 165, 436, 437.

Eimer, colour variation in _Lacerta muralis_, 361.

_Emmelesia unifasciata_, larva phytophagically variable, 307.

Environment, direct and indirect action of, 686.

_Ephyra punctaria_ and _E. omicronaria_, seasonal dimorphism of, 4.

_Eriogaster lanestris_, larva eaten by lizards, 336.

_Eriotus Pteridis_, resemblance of larva, 320.

_Euchelia Jacobææ_; larva and imago rejected by lizards, 336; constant in all three stages, 405.

_Euchloe_: _E. belia_ and _E. ausonia_, seasonal dimorphism of, 3; _E. belia_, climatic variation of, 47; var. _Simplonia_ in Alps, 48; _E. belemia_, seasonal dimorphism and migration of, 78.

_Euproctus Rusconii_, habits of, 617.

_Eusmerinthus Kindermanni_, larva, 526.

Evershed, J., larva of _C. porcellus_, 188.

Eye-spots; repetition of, 277; development of, 325, 327; terrifying action, 330; resemble flower-buds, 334; useful when rudimentary, 366.

F.

Fatiot, Amphibia of Upper Engadine, 616.

Fechner, on conscious matter, 714.

Filippi, De, _Triton alpestris_, 585.

Forel, Prof., fresh water _Pulmonifera_, 590.

Form-relationship and blood-relationship, not always coincident, 395.

Frantzius, Von, on climate of Mexico, 619.

Frogs, 615, 616, 618; inedible species, 294.

Function, change of, 365.

G.

Gegenbaur, Prof., the skull of Axolotl, 576.

Gehrig, breeding of Axolotl, 565.

Gené, habits of _Euproctus Rusconii_, 617.

Genera, Lepidopterous, show greatest congruence, 459.

Generation, heterogeneous, 679, 698, 702.

Gentry, T. G., phytophagic variability of caterpillars, 306.

Gerstäcker, division of the Diptera, 498.

_Geotriton fuscus_, habits, 617.

Glacial epoch; butterflies monogoneutic during, 19, 72; in N. America, 622.

Gooch, W. D., description of larvæ referred to, 436; crepuscular butterflies, 476; sexual dimorphism of caterpillars, 535.

Gooseberry, not increased in size, 654.

Goss, H., larva of _C. porcellus_, 188.

Gosse, P. H., embryonic larva of _P. Homerus_, 167.

_Grapta interrogationis_, experiments with, 149.

Green colour of caterpillars, 293, 310.

Growth, law of, 655.

Gynandromorphism in butterflies, 249.

_Gynanisa Isis_, young larva, 166.

H.

Haeckel, Prof., on metagenesis, 80, 83; on ontogeny, 270; on adaptation, 281, 589; on the biogenetic law, 611; on reproduction and growth, 664; the plastidule theory, 667.

Hare, white variation of, 660.

Hartmann, E. von; his views examined, 645; on variability, 646, 652, 655, 664; on heredity, 657; his “Philosophy of the Unconscious,” 670; on correlation, 670, 673; on the nature of species, 671; on design in nature, 696; on the sensibility of atoms, 714.

Helmholtz, Prof., on natural laws, 668; on the senses, 711.

_Hemaris hylas_, larva, 255.

Heredity, alternating and continuous, 24; cyclical, 66; homochronic, 63, 431; not mechanical, 657; nature of, 667.

Herrich-Schäffer, wing neuration of butterflies, 449.

Hertwig, on teeth of Amphibia, 376.

Heterogenesis, definition of, 82, 96; parallelism between and metamorphosis, 86; origination of, 89.

Heyden, Von, reproduction of _Aphis_, 97.

Hilgendorf, on fossil shells, 109.

_Hipparchia semele_, colour variations, 8.

Hoffmann, Ernst, on immigration of European butterflies, 77.

Horsfield and Moore, figures of caterpillars referred to, 193, 195, 196, 243, 253, 261.

Hübner, figures of caterpillars referred to, 193, 208, 211, 218, 231, 267.

Humboldt, Baron, on the Lake of Mexico, 608, 621.

Huxley, Prof., “Anatomy of Invertebrated Animals” referred to, 498.

_Hydromedusæ_, alternation of generations in, 83; want of parallelism in different generations of, 395.

Hydrozoa, asexual reproduction and polymorphosis, 83.

Hymenoptera, incongruence among, 481; imaginal characters, 481; causes of incongruence, 486.

I.

Ichthyodea, characters of, 577, 579.

Incongruence; in Lepidopterous families, 437; genera, 446, 449; species, 451; varieties, 456; two kinds of, 458, 502; in Hymenoptera, 481; in Diptera, 488; different forms of, 503; dependent upon action of environment, 505, 507, 508.

Inheritance; homochronic, 63, 431; definition of cyclical, 66; limited by sex, 68.

Insects, ancestry of, 493.

Intermaxillary gland of Axolotl, 623.

J.

Jullien, on _Lissotriton punctatus_, 591.

K.

Kant, referred to, 638, 709.

Kirby, W. F., “Synonymic Catalogue” referred to, 2, 49, 435, 449.

Kleemann, larva of _S. Ligustri_, 259.

Knaggs, Dr. H. G., seasonal dimorphism of _S. illustraria_, 4.

Kölliker, Prof., experiments with Axolotl, 564; characters of Axolotl, 575.

L.

_Lacerta muralis_, colour variations, 361.

Lake of Mexico, 603, 608, 621.

Lange, F. A., “History of Materialism” referred to, 645, 656.

Langer, Prof., experiments with _Pelobates_ tadpoles, 607.

Lankester, Prof. E. R., on degeneration, 583.

_Lasiocampa Pini_, larva eaten by lizards, 336; variable in two stages, 405.

Lepidoptera; foes, 8; larva and imago independently variable, 401; species constant in three stages, 405; species variable in three stages, 405; variable in two stages, 405; variable in one stage, 406; causes of variability of pupæ, 411; case of incongruence among pupæ, 540.

_Leptodora hyalina_, development, 93.

_Lepus timidus_, white variations of, 662.

Leuckart, reproduction of _Ascaris nigrovenosa_, 90; on growth, 654.

Leydig, on sexual larvæ of _Triton_, 591.

_Limenitis Artemis_ and _L. Proserpina_, dimorphic in both sexes, 32; _L. Camilla_, constant in three stages, 405.

Lines, dorsal, subdorsal, supra- and infra-spiracular, 175.

_Lissotriton punctatus_, sexual larvæ, 591, 595.

Lizards, colour variation of, 361; rejection of caterpillars by, 336.

Local forms, distinct from climatic varieties, 45; produced by isolation, 109.

Lockyer, B., young _Noctua_ larvæ, 166.

_Lophostethus Dumolinii_, larva, 527.

_Lophura hyas_, larva, 254.

Lubbock, Sir John, insect metamorphosis, 65, 431; derivation of metagenesis, 83; colours of caterpillars, 294; ancestry of insects, 493.

_Lycæna pseudargiolus_, larva and ants, 290.

M.

_Macroglossa_, larvæ of, 245; _M. stellatarum_, oviposition of, 245; 1st, 2nd, and 3rd larval stages, 246; 4th and 5th stages, 247; di- and polymorphism of larva, 247; pupa of, 250; _M. belis_, and _M. pyrrhosticta_, larvæ, 255.

Markings, general biological value of, 285; special biological value of, 308; subordinate, 347; of _Sphingidæ_, evolution of, 380.

Marsh, Prof., on _Siredon lichenoides_, 567.

Matter, assumption of, 711; conscious, 714.

Mayer, Paul, insect phylogeny, 493.

McLachlan, R., phytophagic variability, 305.

Mechanism and teleology, 694.

_Medusæ_, internal parasitism, 699.

_Melanopsis recurrens_, from _Paludina_ bed, 275.

_Menopoma_, characters of, 579.

Mérian, Madame, figures of caterpillars referred to, 195, 232, 263, 268.

Metagenesis, defined, 81, 96; derivation, 83.

Metamorphosis, 430.

Mexico, climate of, 619.

Millière, figure of larva referred to, 254.

Mimicry, 648, 663.

Möller, L., phytophagic variability, 305.

Mono- and digoneutic species, 16.

Moore, F., figures of caterpillars referred to, 436, 526.

Morris, affinities of _Apatura_ and _Nymphalis_, 438.

Moths, seasonal dimorphism in, 4; resembling splinters, 292.

Mühlenpfordt, on Lake of Mexico, 604.

Müller, Fritz, odoriferous organs of butterflies, 102; sexual selection in butterflies, 103; habit and protective resemblance, 290; spiny caterpillars, 293; larva of _Papilio Evander_, 299; reversion in Orchids, 614; maggot-like larvæ of insects, 493; the biogenetic law, 611; mimicry, &c., 665.

Müller, Hermann, larva of _Stauropus Fagi_, 290.

Müller, P. E., _Leptodora hyalina_, 94.

Murray, Andrew, seasonal change of colour, in animals, 7; green caterpillars, 293.

_Muscidæ_, embryonic development, 492.

N.

Nägeli, reversion of cultivated plants, 107.

Natural selection, 112, 361, 704, 705.

Nature, mechanical conception of, 634; harmony of, 697.

Neumayr and Paul, on _Melanopsis_, 275.

_Noctuæ_, change of colour in larvæ, 166; number of legs in young larvæ, 166, 520; ontogeny of larvæ, 520.

Noll, Dr., larva of _Ach. Atropos_, 324.

North America, glaciation of, 622.

Nurse-breeding in Hymenoptera and Diptera, 402.

_Nymphalidæ_, larval classification, 435.

O.

Ontogeny, Fritz Müller and Haeckel on, 270; predominance of new characters in last stage of, 280, 283.

Ontogeny and Phylogeny of Sphinx-markings, 177.

Ophiuroidea, want of parallelism in, 396.

Orchids, reversion in, 614.

Organic compounds, synthesis of, 643.

Organism, parts independently variable, 514.

P.

_Pachylia Ficus_, early stages of larva, 232.

Packard, insect phylogeny, 493.

Pangenesis, theory of, 668.

_Papilio._ _P. Ajax_, seasonal forms, 30; _P. Turnus_, a dimorphic form, 32; _P. Machaon_ and _Podalirius_, seasonally dimorphic in Spain and Italy, 74; _P. Ajax_, experiments with, 126; _P. Merope_, young larva, 166; _P. Homerus_, young larva, 167; _P. Machaon_, larva rejected by lizards, 339.

Parallelism, phyletic, in metamorphic species, 390; phyletic, law of, 510.

_Pararga Ægeria_, sexually dimorphic, 68; climatic variation of, 68.

Pascoe, F. P., “Zoological Classification” referred to, 488, 498.

_Pelobates_, experiments with tadpoles, 607.

_Pergesa Mongoliana_, larva, 194.

_Philampelus achemon_ and _P. satellitia_, larvæ, 523; _P. labruscæ_, larva, 195; _P. vitis_, and _P. anchemolus_, larvæ, 232.

Philosophy, function of, 640.

_Phyciodes Tharos_ and _P. Marcia_, seasonal dimorphism of, 4; experiments with, 140.

Phylogeny, conclusions from, 270; and ontogeny of Sphinx-markings, 177; of insects, 493.

_Pierinæ_, seasonal dimorphism of, 13; analogous seasonal dimorphism in, 60, 108; experiments with, 122.

_Pieris Napi_, experiments with, 13; summer form the younger, 29; reversion of, caused by mechanical vibration, 38; var. _Bryoniæ_, the potential winter form, 39; experiments with this var., 40; this var. the parent form of _Napi_, 41; a climatic var., 41; very variable, 43; variability due to crossing, 43; var. _æstiva_ more variable than var. _vernalis_, 43; _P. Napi_, summer and winter forms compared, 56; incongruence in this species, 457; _P. Krueperi_, seasonal dimorphism of, 78; _P. Brassicæ_, larva rejected by lizards, 337; constant in three stages, 405; photographic sensitiveness of pupa, 405; _P. Napi_, variable in two stages, 405.

Plants, cultivated, 107; sterility of reverted, 596.

Plastidule theory, 667.

_Plebeius amyntas_ and _P. polysperchon_, seasonal dimorphism, 2; _P. Alexis_, do., 3; _P. pseudargiolus_ and _P. violacea_, do., 4; _P. agestis_, do., 50; polymorphism of females in this genus, 251.

Pluvial period, 621.

Polar animals, colour of, 658, 660.

_Polyommatus phlæas_, distribution and climatic variation, 49; seasonal dimorphism, 50; Italian summer and winter forms compared, 55.

_Polyptychus dentatus_, larva, 244.

Ptarmigan, seasonal colours of, 6.

_Pterogon_, larvæ of, 255; _P. ænotheræ_, larva, 256.

_Pulmonifera_, functional change in lungs, 590.

_Pygæra bucephala_, larva rejected by lizards, 337.

Q.

Quatrefages, De, spermatozoa of _Amblystoma_, 593.

R.

_Rana temporaria_ of Upper Engadine, 618.

Ratzeburg, larva of _Anc. Pinastri_, 265.

Reproduction and growth, 664.

Reversion, of species, 611; two modes of, 612; periodic, 613.

_Rhopalocera_, characters of, 433, 471.

_Rhytina Stelleri_, extinction of, 651.

Riley, C. V., descriptions of caterpillars referred to, 437, 521, 522; on sexual dimorphism in caterpillar, 535.

Ring-spots, 325; development, 327; signs of distastefulness, 341; resembling berries, 344.

Rösel, breeding of _Aras. Levana_ by, 6; on larva of _Deil. Euphorbiæ_, 206; of _D. Galii_, 213; of _Smer. Tiliæ_, 236; of _S. ocellatus_, 240; of _Anc. Pinastri_, 265, 268.

Roux, Dr. W., struggle of parts in the organism, 689.

Rutherford, D. G., colour variations of _Ater. meleagris_, 8.

S.

Sacc, on sterility of _Amblystoma_, 593.

Salamanders, habits of Italian land species, 617; oviposition of, 630.

_Salamandra atra_, experiments with, 615.

_Salamandrina_, characters of, 577; _S. perspicillata_, habits of, 617.

Sars, development of _Leptodora hyalina_, 94.

_Saturnia._ _S. Yamamai_, variable in first stage only, 406; _S. carpini_, development of larva of local forms, 419.

_Satyrinæ_, hibernation of larvæ, 73.

Saussure, De, on _Siredon Mexicanus_, 565, 602; physical character of Mexican Lake, 603.

Saw-flies, protective habits of larvæ, 290.

Schmankewitsch, transformation of _Artemia_, 635.

Schmidt, Oscar, on convergence of character, 396, 459; on variability, 654.

Schreibers, sexual _Triton_ larvæ, 591; arrested tadpoles, 607.

Schulze, F. E., parasitism in _Medusæ_, 699.

Science, function of, 640.

Scudder, S. H., embryonic larvæ of butterflies, 166.

Seasonal dimorphism, origin and significance, 1; seasonal change of colour in animals, 7; and climatic variation, 45; seasonal adaptation in caterpillars, 305.

Seidlitz, reproduction of Axolotl, 571; white var. of hare, 662.

_Selenia tetralunaria_, _S. illunaria_, _S. lunaria_, and _S. illustraria_, seasonal dimorphism, 4.

Semper, C., origin of alternation of generations, 84; transformation of _Amblystoma mavortium_, 629.

Semper, G., young Sphinx-larvæ, 166; figures of caterpillars referred to, 522.

Senses, physiology of, 711.

Sepp, figure of caterpillar referred to, 262.

_Sesiidæ_, affinities of, 370.

Sexual dimorphism, of butterflies, 32, 250; of caterpillars, 308, 527, 534; secondary sexual characters, 62; sexual selection, 69, 102.

Siebold, Von, on _Pulmonifera_, 590.

_Siredon._ _S. Mexicanus_, habits, 565; _S. lichenoides_, transformation, 567, 630; phyletic advance of genus, 584; retention of genus, 610; _S. tigrinus_ from L. St. Isabel, 626.

Slater, J. W., food of gaily coloured caterpillars, 294.

_Smerinthus_, larvæ of, 232; _S. Tiliæ_, 233; 4th stage, 235; _S. Populi_, 236; and stage, 237; 3rd and 4th stages, 238; 5th stage, 239; _S. ocellatus_, 240; dimorphism of larva, 241; _S. Tiliæ_, variable in two stages, 405; North American species of, 453; _S. tatarinovii_, and _S. planus_, larvæ, 244.

Species, causes of transformation of, 116; nature of, 671.

Specific characters, 91; may originate through direct action, 100. Specific constitution, 112.

Spencer, Herbert, theory of descent, 645; variability, 654; law of growth, 655.

Spermatozoa, of _Amblystoma_, 593; of _Lissotriton punctatus_, 595.

Speyer, Dr., seasonal dimorphism of moths, 4; of _P. phlæas_ in Germany, 50.

_Sphingidæ_, oviposition, 164; congruence and incongruence in genera, 450.

_Sphinx_-markings, ontogeny and morphology, 177. Larvæ of genus, 259; _S. Convolvuli_, 650. Origination of markings, 273; law of development, 274; forms of markings, 309; _S. Ligustri_, constant in three stages, 405.

Stainton, H. T., larval characters of _Notodontidæ_, 443; young larvæ of _Triph. pronuba_, 520.