Estrelda amandava, pugnacity of the male.

Eubagis, sexual differences of colouring in the species of.

Euchirus longimanus, sound produced by.

Eudromias morinellus.

Eulampis jugularis, colours of the female.

Euler, on the rate of increase in the United States.

Eunomota superciliaris, racket-shaped feathers in the tail of.

Eupetomena macroura, colours of the female.

Euphema splendida.

Euplocamus erythrophthalmus, possession of spurs by the female.

Europe, ancient inhabitants of.

Europeans, difference of, from Hindoos; hairiness of, probably due to reversion.

Eurostopodus, sexes of.

Eurygnathus, different proportions of the head in the sexes of.

Eustephanus, sexual differences of species of; young of.

Exaggeration of natural characters by man.

Exogamy.

Experience, acquisition of, by animals.

Expression, resemblances in, between man and the apes.

Extinction of races, causes of.

Eye, destruction of the; change of position in; obliquity of, regarded as a beauty by the Chinese and Japanese.

Eyebrows, elevation of; development of long hairs in; in monkeys; eradicated in parts of South America and Africa; eradication of, by the Indians of Paraguay.

Eyelashes, eradication of, by the Indians of Paraguay.

Eyelids, coloured black, in part of Africa.

Eyes, pillared, of the male of Chloeon; difference in the colour of, in the sexes of birds.

Eyton, T.C., observations on the development of the horns in the fallow deer.

Eyzies, Les, human remains from.

Fabre, M., on the habits of Cerceris.

Facial bones, causes of modification of the.

Faculties, diversity of, in the same race of men; inheritance of; diversity of, in animals of the same species; mental variation of, in the same species; of birds.

Fakirs, Indian, tortures undergone by.

Falco leucocephalus.

Falco peregrinus.

Falco tinnunclus.

Falcon, peregrine, new mate found by.

Falconer, H., on the mode of fighting of the Indian elephant; on canines in a female deer; on Hyomoschus aquaticus.

Falkland Islands, horses of.

Fallow-deer, different coloured herds of.

Famines, frequency of, among savages.

Farr, Dr., on the effects of profligacy; on the influence of marriage on mortality.

Farrar, F.W., on the origin of language; on the crossing or blending of languages; on the absence of the idea of God in certain races of men; on early marriages of the poor; on the middle ages.

Farre, Dr., on the structure of the uterus.

Fashions, long prevalence of, among savages.

Faye, Prof., on the numerical proportion of male and female births in Norway and Russia; on the greater mortality of male children at and before birth.

Feathers, modified, producing sounds; elongated, in male birds; racket-shaped; barbless and with filamentous barbs in certain birds; shedding of margins of.

Feeding, high, probable influence of, in the pairing of birds of different species.

Feet, thickening of the skin on the soles of the; modification of, in man.

Felis canadensis, throat-ruff of.

Felis pardalis and F. mitis, sexual difference in the colouring of.

Female, behaviour of the, during courtship.

Female birds, differences of.

Females, presence of rudimentary male organs in; preference of, for certain males; pursuit of, by males; occurrence of secondary sexual characters in; development of male character by.

Females and males, comparative numbers of; comparative mortality of, while young.

Femur and tibia, proportions of, in the Aymara Indians.

Fenton, Mr., decrease of Maories; infanticide amongst the Maories.

Ferguson, Mr., on the courtship of fowls.

Fertilisation, phenomena of, in plants; in the lower animals.

Fertility lessened under changed conditions.

Fevers, immunity of Negroes and Mulattoes from.

Fiber zibethicus, protective colouring of it.

Fick, H., effect of conscription for military service.

Fidelity, in the elephant; of savages to one another; importance of.

Field-slaves, difference of, from house-slaves.

Fiji Archipelago, population of the.

Fiji Islands, beards of the natives; marriage-customs of the.

Fijians, burying their old and sick parents alive; estimation of the beard among the; admiration of, for a broad occiput.

Filial affection, partly the result of natural selection.

Filum terminale.

Finch, racket-shaped feathers in the tail of a.

Finches, spring change of colour in; British, females of the.

Fingers, partially coherent, in species of Hylobates.

Finlayson, on the Cochin Chinese.

Fire, use of.

Fischer, on the pugnacity of the male of Lethrus cephalotes.

Fischer, F. Von, on display of brightly coloured parts by monkeys in courtship.

Fish, eagerness of male; proportion of the sexes in; sounds produced by.

Fishes, kidneys of, represented by Corpora Wolffiana in the human embryo; male, hatching ova in their mouths; receptacles for ova possessed by; relative size of the sexes in; fresh-water, of the tropics; protective resemblances in; change of colour in; nest-building; spawning of; sounds produced by; continued growth of.

Flamingo, age of mature plumage.

Flexor pollicis longus, similar variation of, in man.

Flies, humming of.

Flint tools.

Flints, difficulty of chipping into form.

Florida, Quiscalus major in.

Florisuga mellivora.

Flounder, coloration of the.

Flower, W.H., on the abductor of the fifth metatarsal in apes; on the position of the Seals; on the Pithecia monachu; on the throat-pouch of the male bustard.

Fly-catchers, colours and nidification of.

Foetus, human, woolly covering of the; arrangement of the hair on.

Food, influence of, upon stature.

Foot, prehensile power of the, retained in some savages; prehensile, in the early progenitors of man.

Foramen, supra-condyloid, exceptional occurrence of in the humerus of man; in the early progenitors of man.

Forbes, D., on the Aymara Indians; on local variation of colour in the Quichuas; on the hairlessness of the Aymaras and Quichuas; on the long hair of the Aymaras and Quichaus.

Forel, F., on white young swans.

Forester, Hon. O.W., on an orphan hawk.

Formica rufa, size of the cerebral ganglia in.

Fossils, absence of, connecting man with the apes.

Fowl, occurrence of spurs in the female; game, early pugnacity of; Polish, early development of cranial peculiarities of; variations in plumage of; examples of correlated development in the; domestic, breeds and sub-breeds of.

Fowls, spangled Hamburg; inheritance of changes of plumage by; sexual peculiarities in, transmitted only to the same sex; loss of secondary sexual characters by male; Polish, origin of the crest in; period of inheritance of characters by; cuckoo-; development of the comb in; numerical proportion of the sexes in; courtship of; mongrel, between a black Spanish cock and different hens; pencilled Hamburg, difference of the sexes in; Spanish, sexual differences of the comb in; spurred, in both sexes.

Fox, W.D., on some half-tamed wild ducks becoming polygamous, and on polygamy in the guinea-fowl and canary-bird; on the proportion of the sexes in cattle; on the pugnacity of the peacock; on a nuptial assembly of magpies; on the finding of new mates by crows; on partridges living in triplets; on the pairing of a goose with a Chinese gander.

Foxes, wariness of young, in hunting districts; black.

Fraser, C., on the different colours of the sexes in a species of Squilla.

Fraser, G., colours of Thecla.

Frere, Hookham, quoting Theognis on selection in mankind.

Fringilla cannabina.

Fringilla ciris, age of mature plumage in.

Fringilla cyanea, age of mature plumage in.

Fringilla leucophrys, young of.

Fringilla spinus.

Fringilla tristis, change of colour in, in spring; young of.

Fringillidae, resemblance of the females of distinct species of.

Frog, bright coloured and distasteful to birds.

Frogs, male; temporary receptacles for ova possessed by; ready to breed before the females; fighting of; vocal organs of.

Frontal bone, persistence of the suture in.

Fruits, poisonous, avoided by animals.

Fuegians, difference of stature among the; power of sight in the; skill of, in stone-throwing; resistance of the, to their severe climate; mental capacity of the; quasi-religious sentiments of the; resemblance of, in mental characters, to Europeans; mode of life of the; aversion of, to hair on the face; said to admire European women.

Fulgoridae, songs of the.

Fur, whiteness of, in Arctic animals in winter.

Fur-bearing animals, acquired sagacity of.

Gallicrex, sexual difference in the colour of the irides in.

Gallicrex cristatus, pugnacity of male; red carbuncle occurring in the male during the breeding-season.

Gallinaceae, frequency of polygamous habits and of sexual differences in the; love-gestures of; decomposed feathers in; stripes of young; comparative sexual differences between the species of; plumage of.

Gallinaceous birds, weapons of the male; racket-shaped feathers on the heads of.

Gallinula chloropus, pugnacity of the male.

Galloperdix, spurs of; development of spurs in the female.

Gallophasis, young of.

Galls.

Gallus bankiva, neck-hackles of.

Gallus Stanleyi, pugnacity of the male.

Galton, Mr., on hereditary genius; gregariousness and independence in animals; on the struggle between the social and personal impulses; on the effects of natural selection on civilised nations; on the sterility of sole daughters; on the degree of fertility of people of genius; on the early marriages of the poor; on the ancient Greeks; on the Middle Ages; on the progress of the United States; on South African notions of beauty.

Gammarus, use of the chelae of.

Gammarus marinus.

Gannets, white only when mature.

Ganoid fishes.

Gaour, horns of the.

Gap between man and the apes.

Gaper, sexes and young of.

Gardner, on an example of rationality in a Gelasimus.

Garrulus glandarius.

Gartner, on sterility of hybrid plants.

Gasteropoda, pulmoniferous, courtship of.

Gasterosteus, nidification of.

Gasterosteus leiurus.

Gasterosteus trachurus.

Gastrophora, wings of, brightly coloured beneath.

Gauchos, want of humanity among the.

Gaudry, M., on a fossil monkey.

Gavia, seasonal change of plumage in.

Geese, clanging noise made by; pairing of different species of; Canada, selection of mates by.

Gegenbaur, C., on the number of digits in the Ichthyopterygia; on the hermaphroditism of the remote progenitors of the vertebrata; two types of nipple in mammals.

Gelasimus, proportions of the sexes in a species of; use of the enlarged chelae of the male; pugnacity of males of; rational actions of a; difference of colour in the sexes of a species of.

Gemmules, dormant in one sex.

Genius, hereditary.

Genius, fertility of men and women of.

Geoffroy St.-Hilaire, Isid., on the recognition of women by male quadrumana; on monstrosities; coincidences of arrested development with polydactylism; on animal-like anomalies in the human structure; on the correlation of monstrosities; on the distribution of hair in man and monkeys; on the caudal vertebrae of monkeys; on correlated variability; on the classification of man; on the long hair on the heads of species of Semnopithecus; on the hair in monkeys; on the development of horns in female deer; and F. Cuvier, on the mandrill; on Hylobates.

Geographical distribution, as evidence of specific distinctions in man.

Geometrae, brightly coloured beneath.

Geophagus, frontal protuberance of, male; eggs hatched by the male, in the mouth or branchial cavity.

Georgia, change of colour in Germans settled in.

Geotrupes, stridulation of.

Gerbe, M., on the nest-building of Crenilabus massa and C. Melops.

Gerland, Dr., on the prevalence of infanticide; on the extinction of races.

Gervais, P., on the hairiness of the gorilla; on the mandrill.

Gesture-language.

Ghost-moth, sexual difference of colour in the.

Giard, M., disputes descent of vertebrates from Ascidians; colour of sponges and Ascidians; musky odour of Sphinx.

Gibbon, voice of.

Gibbon, Hoolock, nose of.

Gibbs, Sir D., on differences of the voice in different races of men.

Gill, Dr., male seals larger than females; sexual differences in seals.

Giraffe, its mode of using the horns; mute, except in the rutting season.

Giraud-Teulon, on the cause of short sight.

Glanders, communicable to man from the lower animals.

Glands, odoriferous, in mammals.

Glareola, double moult in.

Glomeris limbata, difference of colour in the sexes of.

Glow-worm, female, apterous; luminosity of the.

Gnats, dances of; auditory powers of.

Gnu, skeletons of, found locked together; sexual differences in colour of the.

Goat, male, wild, falling on his horns; male, odour emitted by; male, wild, crest of the; Berbura, mane, dewlap, etc., of the male; Kemas, sexual difference in the colour of the.

Goats, sexual differences in the horns of; horns of; mode of fighting of; domestic, sexual differences of, late developed; beards of.

Goatsucker, Virginian, pairing of the.

Gobies, nidification of.

God, want of the idea of, in some races of men.

Godron, M., on variability; on difference of stature; on the want of connexion between climate and the colour of the skin; on the colour of the skin; on the colour of infants.

Goldfinch, proportion of the sexes in the; sexual differences of the beak in the; courtship of the.

Goldfinch, North American, young of.

Goldfish.

Gomphus, proportions of the sexes in; difference in the sexes of.

Gonepteryx Rhamni, sexual difference of colour in.

Goodsir, Prof., on the affinity of the lancelet to the ascidians.

Goosander, young of.

Goose, Antarctic, colours of the.

Goose, Canada, pairing with a Bernicle gander.

Goose, Chinese, knob on the beak of the.

Goose, Egyptian.

Goose, Sebastopol, plumage of.

Goose, Snow-, whiteness of the.

Goose, Spur-winged.

Gorilla, semi-erect attitude of the; mastoid processes of the; protecting himself from rain with his hands; manner of sitting; supposed to be a kind of mandrill; polygamy of the; voice of the; cranium of; fighting of male.

Gosse, P.H., on the pugnacity of the male Humming-bird.

Gosse, M., on the inheritance of artificial modifications of the skull.

Gould, B.A., on variation in the length of the legs in man; measurements of American soldiers; on the proportions of the body and capacity of the lungs in different races of men; on the inferior vitality of mulattoes.

Gould, J., on migration of swifts; on the arrival of male snipes before the females; on the numerical proportion of the sexes in birds; on Neomorpha Grypus; on the species of Eustephanus; on the Australian musk-duck; on the relative size of the sexes in Briziura lobata and Cincloramphus cruralis; on Lobivanellus lobatus; on habits of Menura Alberti; on the rarity of song in brilliant birds; on Selasphorus platycerus; on the Bower-birds; on the ornamental plumage of the Humming-birds; on the moulting of the ptarmigan; on the display of plumage by the male Humming-birds; on the shyness of adorned male birds; on the decoration of the bowers of Bower-birds; on the decoration of their nest by Humming-birds; on variation in the genus Cynanthus; on the colour of the thighs in a male parrakeet; on Urosticte Benjamini; on the nidification of the Orioles; on obscurely-coloured birds building concealed nests; on trogons and king-fishers; on Australian parrots; on Australian pigeons; on the moulting of the ptarmigan; on the immature plumage of birds; on the Australian species of Turnix; on the young of Aithurus polytmus; on the colours of the bills of toucans; on the relative size of the sexes in the marsupials of Australia; on the colours of the Marsupials.

Goureaux, on the stridulation of Mutilla europaea.

Gout, sexually transmitted.

Graba, on the Pied Ravens of the Feroe Islands; variety of the Guillemot.

Gradation of secondary sexual characters in birds.

Grallatores, absence of secondary sexual characters in; double moult in some.

Grallina, nidification of.

Grasshoppers, stridulation of the.

Gratiolet, Prof., on the anthropomorphous apes; on the evolution of the anthropomorphous apes; on the difference in the development of the brains of apes and of man.

Gray, Asa, on the gradation of species among the Compositae.

Gray, J.E., on the caudal vertebrae of monkeys; on the presence of rudiments of horns in the female of Cervulus moschatus; on the horns of goats and sheep; on crests of male antelopes; on the beard of the ibex; on the Berbura goat; on sexual differences in the coloration of Rodents; ornaments of male sloth; on the colours of the Elands; on the Sing-sing antelope; on the colours of goats; on Lemur Macaco; on the hog-deer.

"Greatest happiness principle."

Greeks, ancient.

Green, A.H., on beavers fighting; on the voice of the beaver.

Greenfinch, selected by a female canary.

Greg, W.R., on the effects of natural selection on civilised nations; on the early marriages of the poor; on the Ancient Greeks.

Grenadiers, Prussian.

Greyhounds, numerical proportion of the sexes in; numerical proportion of male and female births in.

Grouse, red, monogamous; pugnacity of young male; producing a sound by beating their wings together; duration of courtship of; colours and nidification of.

Gruber, Dr., on the occurrence of the supra-condyloid foramen in the humerus of man; on division of malar bone; stridulation of locust; on ephippiger.

Grus americanus, age of mature plumage in; breeding in immature plumage.

Grus virgo, trachea of.

Gryllus campestris, pugnacity of male.

Gryllus domesticus.

Grypus, sexual differences in the beak in.

Guanacoes, battles of; canine teeth of.

Guanas, strife for women among the; polyandry among the.

Guanche skeletons, occurrence of the supra-condyloid foramen in the humerus of.

Guaranys, proportion of men and women among; colour of new-born children of the; beards of the.

Guenee, A., on the sexes of Hyperythra.

Guilding, L., on the stridulation of the Locustidae.

Guillemot, variety of the.

Guinea, sheep of, with males only horned.

Guinea-fowl, monogamous; occasional polygamy of the; markings of the.

Guinea-pigs, inheritance of the effects of operations by.

Gulls, seasonal change of plumage in; white.

Gunther, Dr., on paddle of Ceradotus; on hermaphroditism in Serranus; on male fishes hatching ova in their mouths; on mistaking infertile female fishes for males; on the prehensile organs of male Plagiostomous fishes; spines and brushes on fishes; on the pugnacity of the male salmon and trout; on the relative size of the sexes in fishes; on sexual differences in fishes; on the genus Callionymus; on a protective resemblance of a pipe-fish; on the genus Solenostoma; on the coloration of frogs and toads; combat of Testudo elegans; on the sexual differences in the Ophidia; on differences of the sexes of lizards.

Gynanisa Isis, ocellated spots of.

Gypsies, uniformity of, in various parts of the world.

Habits, bad, facilitated by familiarity; variability of the force of.

Haeckel, E., on the origin of man; on rudimentary characters; on death caused by inflammation of the vermiform appendage; on the canine teeth in man; on the steps by which man became a biped; on man as a member of the Catarrhine group; on the position of the Lemuridae; on the genealogy of the Mammalia; on the lancelet; on the transparency of pelagic animals; on the musical powers of women.

Hagen, H., and Walsh, B.D., on American Neuroptera.

Hair, development of, in man; character of, supposed to be determined by light and heat; distribution of, in man; possibly removed for ornamental purposes; arrangement and direction of; of the early progenitors of man; different texture of, in distinct races; and skin, correlation of colour of; development of, in mammals; management of, among different peoples; great length of, in some North American tribes; elongation of the, on the human head; possible inherited effect of plucking out.

Hairiness, difference of, in the sexes in man; variation of, in races of men.

Hairs and excretory pores, numerical relation of, in sheep.

Hairy family, Siamese.

Halbertsma, Prof., hermaphroditism in Serranus.

Hamadryas baboon, turning over stones; mane of the male.

Hamilton, C., on the cruelty of the Kaffirs to animals; on the engrossment of the women by the Kaffir chiefs.

Hammering, difficulty of.

Hancock, A., on the colours of the nudibranch Mollusca.

Hands, larger at birth, in the children of labourers; structure of, in the quadrumana; and arms, freedom of, indirectly correlated with diminution of canines.

Handwriting, inherited.

Handyside, Dr., supernumerary mammae in men.

Harcourt, E. Vernon, on Fringilla cannabina.

Hare, protective colouring of the.

Harelda glacialis.

Hares, battles of male.

Harlan, Dr., on the difference between field- and house-slaves.

Harris, J.M., on the relation of complexion to climate.

Harris, T.W., on the Katy-did locust; on the stridulation of the grasshoppers; on Oecanthus nivalis; on the colouring of Lepidoptera; on the colouring of Saturnia Io.

Harting, spur of the Ornithorhynchus.

Hartman, Dr., on the singing of Cicada septendecim.

Hatred, persistence of.

Haughton, S., on a variation of the flexor pollicis longus in man.

Hawks, feeding orphan nestling.

Hayes, Dr., on the diverging of sledge-dogs on thin ice.

Haymond, R., on the drumming of the male Tetrao umbellus; on the drumming of birds.

Head, altered position of, to suit the erect attitude of man; hairiness of, in man; processes of, in male beetles; artificial alterations of the form of the.

Hearne, on strife for women among the North American Indians; on the North American Indians' notion of female beauty; repeated elopements of a North American woman.

Heart, in the human embryo.

Heat, supposed effects of.

Hectocotyle.

Hedge-warbler, young of the.

Heel, small projection of, in the Aymara Indians.

Hegt, M., on the development of the spurs in peacocks.

Heliconidae, mimicry of, by other butterflies.

Heliopathes, stridulation peculiar to the male.

Heliothrix auriculata, young of.

Helix pomatia, example of individual attachment in.

Hellins, J., proportions of sexes of Lepidoptera reared by.

Helmholtz, on pleasure derived from harmonies; on the human eye; on the vibration of the auditory hairs of crustacea; the physiology of harmony.

Hemiptera.

Hemitragus, beardless in both sexes.

Hemsbach, M. von, on medial mamma in man.

Hen, clucking of.

Hepburn, Mr., on the autumn song of the water-ouzel.

Hepialus humuli, sexual difference of colour in the.

Herbs, poisonous, avoided by animals.

Hermaphroditism, of embryos; in fishes.

Herodias bubulcus, vernal moult of.

Heron, Sir R., on the habits of peafowl.

Herons, love-gestures of; decomposed feathers in; breeding plumage of; young of the; sometimes dimorphic; continued growth of crest and plumes in the males of some; change of colour in some.

Hesperomys cognatus.

Hetaerina, proportion of the sexes in; difference in the sexes of.

Heterocerus, stridulation of.

Hewitt, Mr., on a game-cock killing a kite; on the recognition of dogs and cats by ducks; on the pairing of a wild duck with a pintail drake; on the courtship of fowls; on the coupling of pheasants with common hens.

Hilgendorf, sounds produced by crustaceans.

Hindoo, his horror of breaking his caste.

Hindoos, local difference of stature among; difference of, from Europeans; colour of the beard in.

Hipparchia Janira, instability of the ocellated spots of.

Hippocampus, development of; marsupial receptacles of the male.

Hippocampus minor.

Hippopotamus, nakedness of.

Hips, proportions of, in soldiers and sailors.

Hodgson, S., on the sense of duty.

Hoffberg, on the horns of the reindeer; on sexual preferences shewn by reindeer.

Hoffman, Prof., protective colours; fighting of frogs.

Hog, wart-; river-.

Hog-deer.

Holland, Sir H., on the effects of new diseases.

Homologous structures, correlated variation of.

Homoptera, stridulation of the, and Orthoptera, discussed.

Honduras, Quiscalus major in.

Honey-buzzard of India, variation in the crest of.

Honey-sucker, females and young of.

Honey-suckers, moulting of the; Australian, nidification of.

Honour, law of.

Hooker, Dr., forbearance of elephant to his keeper; on the colour of the beard in man.

Hookham, Mr., on mental concepts in animals.

Hoolock Gibbon, nose of.

Hoopoe, sounds produced by male.

Hoplopterus armatus, wing-spurs of.

Hornbill, African, inflation of the neck-wattle of the male during courtship.

Hornbills, sexual difference in the colour of the eyes in; nidification and incubation of.

Horne, C., on the rejection of a brightly-coloured locust by lizards and birds.

Horns, sexual differences of, in sheep and goats; loss of, in female merino sheep; development of, in deer; development in antelopes; from the head and thorax, in male beetles; of deer; originally a masculine character in sheep; and canine teeth, inverse development of.

Horse, fossil, extinction of the, in South America; polygamous; canine teeth of male; winter change of colour.

Horses, rapid increase of, in South America; diminution of canine teeth in; dreaming; of the Falkland Islands and Pampas; numerical proportion of the sexes, in; lighter in winter in Siberia; sexual preferences in; pairing preferently with those of the same colour; numerical proportion of male and female births in; formerly striped.

Hottentot women, peculiarities of.

Hottentots, lice of; readily become musicians; notions of female beauty of the; compression of nose by.

Hough, Dr. S., men's temperature more variable than women's; proportion of sexes in man.

House-slaves, difference of, from field-slaves.

Houzeau, on the baying of the dog; on reason in dogs; birds killed by telegraph wires; on the cries of domestic fowls and parrots; animals feel no pity; suicide in the Aleutian Islands.

Howorth, H.H., extinction of savages.

Huber, P., on ants playing together; on memory in ants; on the intercommunication of ants; on the recognition of each other by ants after separation.

Huc, on Chinese opinions of the appearance of Europeans.

Huia, the, of New Zealand.

Human, man, classed alone in a kingdom.

Human sacrifices.

Humanity, unknown among some savages; deficiency of, among savages.

Humboldt, A. von, on the rationality of mules; on a parrot preserving the language of a lost tribe; on the cosmetic arts of savages; on the exaggeration of natural characters by man; on the red painting of American Indians.

Hume, D., on sympathetic feelings.

Humming-bird, racket-shaped feathers in the tail of a; display of plumage by the male.

Humming-birds, ornament their nests; polygamous; proportion of the sexes in; sexual differences in; pugnacity of male; modified primaries of male; coloration of the sexes of; display by; nidification of the; colours of female; young of.

Humour, sense of, in dogs.

Humphreys, H.N., on the habits of the stickleback.

Hunger, instinct of.

Huns, ancient, flattening of the nose by the.

Hunter, J., on the number of species of man; on secondary sexual characters; on the general behaviour of female animals during courtship; on the muscles of the larynx in song-birds; on strength of males; on the curled frontal hair of the bull; on the rejection of an ass by a female zebra.

Hunter, W.W., on the recent rapid increase of the Santali; on the Santali.

Huss, Dr. Max, on mammary glands.

Hussey, Mr., on a partridge distinguishing persons.

Hutchinson, Col., example of reasoning in a retriever.

Hutton, Captain, on the male wild goat falling on his horns.

Huxley, T.H., on the structural agreement of man with the apes; on the agreement of the brain in man with that of lower animals; on the adult age of the orang; on the embryonic development of man; on the origin of man; on variation in the skulls of the natives of Australia; on the abductor of the fifth metatarsal in apes; on the nature of the reasoning power; on the position of man; on the suborders of primates; on the Lemuridae; on the Dinosauria; on the amphibian affinities of the Ichthyosaurians; on variability of the skull in certain races of man; on the races of man; Supplement on the brain.

Hybrid birds, production of.

Hydrophobia, communicable between man and the lower animals.

Hydroporus, dimorphism of females of.

Hyelaphus porcinus.

Hygrogonus.

Hyla, singing species of.

Hylobates, absence of the thumb in; upright progression of some species of; maternal affection in a; direction of the hair on the arms of species of; females of, less hairy below than males.

Hylobates agilis, hair on the arms of; musical voice of the; superciliary ridge of; voice of.

Hylobates hoolock, sexual difference of colour in.

Hylobates lar, hair on the arms of; female less hairy.

Hylobates leuciscus, song of.

Hylobates syndactylus, laryngeal sac of.

Hylophila prasinana.

Hymonoptera, large size of the cerebral ganglia in; classification of; sexual differences in the wings of; aculeate, relative size of the sexes of.

Hymenopteron, parasitic, with a sedentary male.

Hyomoschus aquaticus.

Hyperythra, proportion of the sexes in.

Hypogymna dispar, sexual difference of colour in.

Hypopyra, coloration of.

Ibex, male, falling on his horns; beard of the.

Ibis, white, change of colour of naked skin in, during the breeding season; scarlet, young of the.

Ibis tantalus, age of mature plumage in; breeding in immature plumage.

Ibises, decomposed feathers in; white; and black.

Ichneumonidae, difference of the sexes in.

Ichthyopterygia.

Ichthyosaurians.

Idiots, microcephalous, their characters and habits; hairiness and animal nature of their actions; microcephalous, imitative faculties of.

Iguana tuberculata.

Iguanas.

illegitimate and legitimate children, proportion of the sexes in.

Imagination, existence of, in animals.

Imitation, of man by monkeys; tendency to, in monkeys,; microcephalous idiots and savages; influence of.

Immature plumage of birds.

Implacentata.

Implements, employed by monkeys; fashioning of, peculiar to man.

Impregnation, period of, influence of, upon sex.

Improvement, progressive, man alone supposed to be capable of.

Incisor teeth, knocked out or filed by some savages.

Increase, rate of; necessity of checks in.

Indecency, hatred of, a modern virtue.

India, difficulty of distinguishing the native races of; Cyprinidae of; colour of the beard in races of men of.

Indian, North American, honoured for scalping a man of another tribe.

Individuality, in animals.

Indolence of man, when free from a struggle for existence.

Indopicus carlotta, colours of the sexes of.

Infanticide, prevalence of; supposed cause of; prevalence and causes of.

Inferiority, supposed physical, of man.

Inflammation of the bowels, occurrence of, in Cebus Azarae.

Inheritance, of long and short sight; of effects of use of vocal and mental organs; of moral tendencies; laws of; sexual; sexually limited.

Inquisition, influence of the.

Insanity, hereditary.

insect, fossil, from the Devonian.

Insectivora, absence of secondary sexual characters in.

Insects, relative size of the cerebral ganglia in; male, appearance of, before the females; pursuit of female, by the males; period of development of sexual characters in; secondary sexual characters of; kept in cages; stridulation.

Insessores, vocal organs of.

Instep, depth of, in soldiers and sailors.

Instinct and intelligence.

Instinct, migratory, vanquishing the maternal.

Instinctive actions, the result of inheritance.

Instinctive impulses, difference of the force; and moral impulses, alliance of.

Instincts, complex origin of, through natural selection; possible origin of some; acquired, of domestic animals; variability of the force of; difference of force between the social and other; utilised for new purposes.

Instrumental music of birds.

Intellect, influence of, in natural selection in civilised society.

Intellectual faculties, their influence on natural selection in man; probably perfected through natural selection.

Intelligence, Mr. H. Spencer on the dawn of.

Intemperance, no reproach among savages; its destructiveness.

Intoxication in monkeys.

Iphias glaucippe.

Iris, sexual difference in the colour of the, in birds.

Ischio-pubic muscle.

Ithaginis cruentus, number of spurs in.

Iulus, tarsal suckers of the males of.

Jackals learning from dogs to bark.

Jack-snipe, coloration of the.

Jacquinot, on the number of species of man.

Jaeger, Dr., length of bones increased from carrying weights; on the difficulty of approaching herds of wild animals; male Silver-pheasant, rejected when his plumage was spoilt.

Jaguars, black.

Janson, E.W., on the proportions of the sexes in Tomicus villosus; on stridulant beetles.

Japan, encouragement of licentiousness in.

Japanese, general beardlessness of the; aversion of the, to whiskers.

Jardine, Sir W., on the Argus pheasant.

Jarrold, Dr., on modifications of the skull induced by unnatural position.

Jarves, Mr., on infanticide in the Sandwich Islands.

Javans, relative height of the sexes of; notions of female beauty.

Jaw, influence of the muscles of the, upon the physiognomy of the apes.

Jaws, smaller proportionately to the extremities; influence of food upon the size of; diminution of, in man; in man, reduced by correlation.

Jay, young of the; Canada, young of the.

Jays, new mates found by; distinguishing persons.

Jeffreys, J. Gwyn, on the form of the shell in the sexes of the Gasteropoda; on the influence of light upon the colours of shells.

Jelly-fish, bright colours of some.

Jenner, Dr., on the voice of the rook; on the finding of new mates by magpies; on retardation of the generative functions in birds.

Jenyns, L., on the desertion of their young by swallows; on male birds singing after the proper season.

Jerdon, Dr., on birds dreaming; on the pugnacity of the male bulbul; on the pugnacity of the male Ortygornis gularis; on the spurs of Galloperdix; on the habits of Lobivanellus; on the spoonbill; on the drumming of the Kalij-pheasant; on Indian bustards; on Otis bengalensis; on the ear-tufts of Sypheotides auritus; on the double moults of certain birds; on the moulting of the honeysuckers; on the moulting of bustards, plovers, and drongos; on the spring change of colour in some finches; on display in male birds; on the display of the under-tail coverts by the male bulbul; on the Indian honey-buzzard; on sexual differences in the colour of the eyes of hornbills; on the markings of the Tragopan pheasant; on the nidification of the Orioles; on the nidification of the hornbills; on the Sultan yellow-tit; on Palaeornis javanicus; on the immature plumage of birds; on representative species of birds; on the habits of Turnix; on the continued increase of beauty of the peacock; on coloration in the genus Palaeornis.

Jevons, W.S., on the migrations of man.

Jews, ancient use of flint tools by the; uniformity of, in various parts of the world; numerical proportion of male and female births among the; ancient, tattooing practised by.

Johnstone, Lieut., on the Indian elephant.

Jollofs, fine appearance of the.

Jones, Albert, proportion of sexes of Lepidoptera, reared by.

Juan Fernandez, humming-birds of.

Junonia, sexual differences of colouring in species of.

Jupiter, comparison with Assyrian effigies.

Kaffir skull, occurrence of the diastema in a.

Kaffirs, their cruelty to animals; lice of the; colour of the; engrossment of the handsomest women by the chiefs of the; marriage-customs of the.

Kalij-pheasant, drumming of the male; young of.

Kallima, resemblance of, to a withered leaf.

Kulmucks, general beardlessness of; aversion of, to hairs on the face; marriage-customs of the.

Kangaroo, great red, sexual difference in the colour of.

Kant, Imm., on duty; on self-restraint; on the number of species of man.

Katy-did, stridulation of the.

Keen, Dr., on the mental powers of snakes.

Keller, Dr., on the difficulty of fashioning stone implements.

Kent, W.S., elongation of dorsal fin of Callionymus lyra; courtship of Labrus mixtus; colours and courtship of Cantharus lineatus.

Kestrels, new mates found by.

Kidney, one, doing double work in disease.

King, W.R., on the vocal organs of Tetrao cupido; on the drumming of grouse; on the reindeer; on the attraction of male deer by the voice of the female.

King and Fitzroy, on the marriage-customs of the Fuegians.

King-crows, nidification of.

Kingfisher, racket-shaped feathers in the tail of a.

Kingfishers, colours and nidification of the; immature plumage of the; young of the.

King Lory, immature plumage of the.

Kingsley, C., on the sounds produced by the Umbrina.

Kirby and Spence, on sexual differences in the length of the snout in Curculionidae; on the courtship of insects; on the elytra of Dytiscus; on peculiarities in the legs of male insects; on the relative size of the sexes in insects; on the Fulgoridae; on the habits of the Termites; on difference of colour in the sexes of beetles; on the horns of the male lamellicorn beetles; on hornlike processes in male Curculionidae; on the pugnacity of the male stag-beetle.

Kite, killed by a game-cock.

Knot, retention of winter plumage by the.

Knox, R., on the semilunar fold; on the occurrence of the supra-condyloid foramen in the humerus of man; on the features of the young Memmon.

Koala, length of the caecum in.

Kobus ellipsiprymnus, proportion of the sexes in.

Kolreuter, on the sterility of hybrid plants.

Koodoo, development of the horns of the; markings of the.

Koppen, F.T., on the migratory locust.

Koraks, marriage customs of.

Kordofan, protuberances artificially produced by natives of.

Korte, on the proportion of sexes in locusts; Russian locusts.

Kovalevsky, A., on the affinity of the Ascidia to the Vertebrata.

Kovalevsky, W., on the pugnacity of the male capercailzie; on the pairing of the capercailzie.

Krause, on a convoluted body at the extremity of the tail in a Macacus and a cat.

Kupffer, Prof., on the affinity of the Ascidia to the Vertebrata.

Labidocera Darwinii, prehensile organs of the male.

Labrus, splendid colours of the species of.

Labrus mixtus, sexual differences in.

Labrus pavo.

Lacertilia, sexual differences of.

Lafresnaye, M. de, on birds of paradise.

Lamarck, on the origin of man.

Lamellibranchiata.

Lamellicorn beetles, horn-like processes from the head and thorax of; influence of sexual selection on.

Lamellicornia, stridulation of.

Lamont, Mr., on the tusks of the walrus; on the use of its tusks by the walrus; on the bladder-nose seal.

Lampornis porphyrurus, colours of the female.

Lampyridae, distasteful to mammals.

Lancelet.

Landois, H., gnats attracted by sound; on the production of sound by the Cicadae; on the stridulating organ of the crickets; on Decticus; on the stridulating organs of the Acridiidae; stridulating apparatus, in Orthoptera; on the stridulation of Necrophorus; on the stridulant organ of Cerambyx heros; on the stridulant organ of Geotrupes; on the stridulating organs in the Cleoptera; on the ticking of Anobium.

Landor, Dr., on remorse for not obeying tribal custom.

Language, an art; articulate, origin of; relation of the progress of, to the development of the brain; effects of inheritance in production of; complex structure of, among barbarous nations; natural selection in; gesture; primeval; of a lost tribe preserved by a parrot.

Languages, presence of rudiments in; classification of; variability of; crossing or blending of; complexity of, no test of perfection or proof of special creation; resemblance of, evidence of community of origin.

Languages and species, identity of evidence of their gradual development.

Lanius, characters of young.

Lanius rufus, anomalous young of.

Lankester, E.R., on comparative longevity; on the destructive effects of intemperance.

Lanugo of the human foetus.

Lapponian language, highly artificial.

Lark, proportion of the sexes in the; female, singing of the.

Larks, attracted by a mirror.

Lartet, E., comparison of cranial capacities of skulls of recent and tertiary mammals; on the size of the brain in mammals; on Dryopithecus; on pre-historic flutes.

Larus, seasonal change of plumage in.

Larva, luminous, of a Brazilian beetle.

Larynx, muscles of the, in songbirds.

Lasiocampa quercus, attraction of males by the female; sexual difference of colour in.

Latham, R.G., on the migrations of man.

Latooka, perforation of the lower lip by the women of.

Laurillard, on the abnormal division of the malar bone in man.

Lawrence, W., on the superiority of savages to Europeans in power of sight; on the colour of negro infants; on the fondness of savages for ornaments; on beardless races; on the beauty of the English aristocracy.

Layard, E.L., on the instance of rationality in a cobra; on the pugnacity of Gallus Stanleyi.

Laycock, Dr., on vital periodicity; theroid nature of idiots.

Leaves, autumn, tints useless.

Lecky, Mr., on the sense of duty; on suicide; on the practice of celibacy; his view of the crimes of savages; on the gradual rise of morality.

Leconte, J.L., on the stridulant organ in the Coprini and Dynastini.

Lee, H., on the numerical proportion of the sexes in the trout.

Leg, calf of the, artificially modified.

Legitimate and illegitimate children, proportion of the sexes in.

Legs, variation of the length of the, in man; proportions of, in soldiers and sailors; front, atrophied in some male butterflies; peculiarities of, in male insects.

Leguay, on the occurrence of the supra-condyloid foramen in the humerus of man.

Lek of the black-cock and capercailzie.

Lemoine, Albert, on the origin of language.

Lemur macaco, sexual difference of colour in.

Lemuridae, ears of the; variability of the muscles in the; position and derivation of the; their origin.

Lemurs, uterus in the.

Lenguas, disfigurement of the ears of the.

Leopards, black.

Lepidoptera, numerical proportions of the sexes in the; colouring of; ocellated spots of.

Lepidosiren.

Leptalides, mimicry of.

Leptorhynchus angustatus, pugnacity of male.

Leptura testacea, difference of colour in the sexes.

Leroy, on the wariness of young foxes in hunting-districts; on the desertion of their young by swallows.

Leslie, D., marriage customs of Kaffirs.

Lesse, valley of the.

Lesson, on the birds of paradise; on the sea-elephant.

Lessona, M., observations on Serranus.

Lethrus cephalotes, pugnacity of the males of.

Leuciscus phoxinus.

Leuckart, R., on the vesicula prostatica; on the influence of the age of parents on the sex of offspring.

Levator claviculae muscle.

Libellula depressa, colour of the male.

Libellulidae, relative size of the sexes of; difference in the sexes of.

Lice of domestic animals and man.

Licentiousness a check upon population; prevalence of, among savages.

Lichtenstein, on Chera progne.

Life, inheritance at corresponding periods of.

Light, effects on complexion; influence of, upon the colours of shells.

Lilford, Lord, the ruff attracted by bright objects.

Limosa lapponica.

Linaria.

Linaria montana.

Lindsay, Dr. W.L., diseases communicated from animals to man; madness in animals; the dog considers his master his God.

Linnaeus, views of, as to the position of man.

Linnet, numerical proportion of the sexes in the; crimson forehead and breast of the; courtship of the.

Lion, polygamous; mane of the, defensive; roaring of the.

Lions, stripes of young.

Lips, piercing of the, by savages.

Lithobius, prehensile appendages of the female.

Lithosia, coloration in.

Littorina littorea.

Livingstone, Dr., manner of sitting of gorilla; on the influence of dampness and dryness on the colour of the skin; on the liability of negroes to tropical fevers after residence in a cold climate; on the spur-winged goose; on weaverbirds; on an African night-jar; on the battle-scars of South African male mammals; on the removal of the upper incisors by the Batokas; on the perforation of the upper lip by the Makalolo; on the Banyai.

Livonia, numerical proportion of male and female births in.

Lizards, relative size of the sexes of; gular pouches of.

Lloyd, L., on the polygamy of the capercailzie and bustard; on the numerical proportion of the sexes in the capercailzie and blackcock; on the salmon; on the colours of the sea-scorpion; on the pugnacity of male grouse; on the capercailzie and blackcock; on the call of the capercailzie; on assemblages of grouse and snipes; on the pairing of a shield-drake with a common duck; on the battles of seals; on the elk.

Lobivanellus, wing-spurs in.

Local influences, effect of, upon stature.

Lockwood, Mr., on the development of Hippocampus.

Lockwood, Rev. S., musical mouse.

Locust, bright-coloured, rejected by lizards and birds.

Locust, migratory; selection by female.

Locustidae, stridulation of the; descent of the.

Locusts, proportion of sexes in; stridulation of.

Longicorn beetles, difference of the sexes of, in colour; stridulation of.

Lonsdale, Mr., on an example of personal attachment in Helix pomatia.

Lophobranchii, marsupial receptacles of the male.

Lophophorus, habits of.

Lophorina atra, sexual difference in coloration of.

Lophornis ornatus.

Lord, J.K., on Salmo lycaodon.

Lory, King; immature plumage of the.

Lory, king, constancy of.

Love-antics and dances of birds.

Lowne, B.T., on Musca vomitoria.

Loxia, characters of young of.

Lubbock, Sir J., on the antiquity of man; on the origin of man; on the mental capacity of savages; on the origin of implements; on the simplification of languages; on the absence of the idea of God among certain races of men; on the origin of the belief in spiritual agencies; on superstitions; on the sense of duty; on the practice of burying the old and sick among the Fijians; on the immorality of savages; on Mr. Wallace's claim to the origination of the idea of natural selection; on the former barbarism of civilised nations; on improvements in the arts among savages; on resemblances of the mental characters in different races of men; on the arts practised by savages; on the power of counting in primeval man; on the prehensile organs of the male Labidocera Darwinii; on Chloeon; on Smynthurus luteus; finding of new mates by jays; on strife for women among the North American Indians; on music; on the ornamental practices of savages; on the estimation of the beard among the Anglo-Saxons; on artificial deformation of the skull; on "communal marriages;" on exogamy; on the Veddahs; on polyandry.

Lucanidae, variability of the mandibles in the male.

Lucanus, large size of males of.

Lucanus cervus, numerical proportion of sexes of; weapons of the male.

Lucanus elaphus, use of mandibles of; large jaws of male.

Lucas, Prosper, on pigeons; on sexual preference in horses and bulls.

Luminosity in insects.

Lunar periods.

Lund, Dr., on skulls found in Brazilian caves.

Lungs, enlargement of, in the Quichua and Aymara Indians; a modified swim-bladder; different capacity of, in races of man.

Luschka, Prof., on the termination of the coccyx.

Luxury, expectation of life uninfluenced by.

Lycaena, sexual differences of colour in species of.

Lycaenae, colours of.

Lyell, Sir C., on the antiquity of man; on the origin of man; on the parallelism of the development of species and languages; on the extinction of languages; on the Inquisition; on the fossil remains of vertebrata; on the fertility of mulattoes.

Lynx, Canadian throat-ruff of the.

Lyre-bird, assemblies of.

Macacus, ears of; convoluted body in the extremity of the tail of; variability of the tail in species of; whiskers of species of.

Macacus brunneus.

Macacus cynomolgus, superciliary ridge of; beard and whiskers of; becoming white with age.

Macacus ecaudatus.

Macacus lasiotus, facial spots of.

Macacus nemestrinus.

Macacus radiatus.

Macacus rhesus, sexual difference in the colour of.

Macalister, Prof., on variations of the palmaris accessorius muscle; on muscular abnormalities in man; on the greater variability of the muscles in men than in women.

Macaws, Mr. Buxton's observations on.

McCann, J., on mental individuality.

McClelland, J., on the Indian Cyprinidae.

Macculloch, Col., on an Indian village without any female children.

Macculloch, Dr., on tertian ague in a dog.

Macgillivray, W., on the vocal organs of birds; on the Egyptian goose; on the habits of woodpeckers; on the habits of the snipe; on the whitethroat; on the moulting of the snipes; on the moulting of the Anatidae; on the finding of new mates by magpies; on the pairing of a blackbird and thrush; on pied ravens; on the guillemots; on the colours of the tits; on the immature plumage of birds.

Machetes, sexes and young of.

Machetes pugnax, supposed to be polygamous; numerical proportion of the sexes in; pugnacity of the male; double moult in.

McIntosh, Dr., colours of the Nemertians.

McKennan, marriage customs of Koraks.

Mackintosh, on the moral sense.

MacLachlan, R., on Apatania muliebris and Boreus hyemalis; on the anal appendages of male insects; on the pairing of dragon-flies; on dragon-flies; on dimorphism in Agrion; on the want of pugnacity in male dragon-flies; colour of ghost-moth in the Shetland Islands.

M'Lennan, Mr., on infanticide; on the origin of the belief in spiritual agencies; on the prevalence of licentiousness among savages; on the primitive barbarism of civilised nations; on traces of the custom of the forcible capture of wives; on polyandry.

Macnamara, Mr., susceptibility of Andaman islanders and Nepalese to change.

M'Neill, Mr., on the use of the antlers of deer; on the Scotch deerhound; on the long hairs on the throat of the stag; on the bellowing of stags.

Macropus, courtship of.

Macrorhinus proboscideus, structure of the nose of.

Magpie, power of speech of; vocal organs of the; nuptial assemblies of; new mates found by; stealing bright objects; young of the; coloration of the.

Maillard, M., on the proportion of the sexes in a species of Papilio from Bourbon.

Maine, Sir Henry, on the absorption of one tribe by another; a desire for improvement not general.

Major, Dr. C. Forsyth, on fossil Italian apes; skull of Bos etruscus; tusks of miocene pigs.

Makalolo, perforation of the upper lip by the.

Malar bone, abnormal division of, in man.

Malay, Archipelago, marriage-customs of the savages of the.

Malays, line of separation between the Papuans and the; general beardlessness of the; staining of the teeth among; aversion of some, to hairs on the face.

Malays and Papuans, contrasted characters of.

Male animals, struggles of, for the possession of the females; eagerness of, in courtship; generally more modified than female; differ in the same way from females and young.

Male characters, developed in females; transfer of, to female birds.

Male, sedentary, of a hymenopterous parasite.

Malefactors.

Males, presence of rudimentary female organs in.

Males and females, comparative numbers of; comparative mortality of, while young.

Malherbe, on the woodpeckers.

Mallotus Peronii.

Mallotus villosus.

Malthus, T., on the rate of increase of population.

Maluridae, nidification of the.

Malurus, young of.

Mammae, rudimentary, in male mammals; supernumerary, in women; of male human subject.

Mammalia, Prof. Owen's classification of; genealogy of the.

Mammals, recent and tertiary, comparison of cranial capacity of; nipples of; pursuit of female, by the males; secondary sexual characters of; weapons of; relative size of the sexes of; parallelism of, with birds in secondary sexual characters; voices of, used especially during the breeding season.

Man, variability of; erroneously regarded as more domesticated than other animals; migrations of; wide distribution of; causes of the nakedness of; supposed physical inferiority of; a member of the Catarrhine group; early progenitors of; transition from ape indefinite; numerical proportions of the sexes in; difference between the sexes; proportion of sexes amongst the illegitimate; different complexion of male and female negroes; secondary sexual characters of; primeval condition of.

Mandans, correlation of colour and texture of hair in the.

Mandible, left, enlarged in the male of Taphroderes distortus.

Mandibles, use of the, in Ammophila; large, of Corydalis cornutus; large, of male Lucanus elaphus.

Mandrill, number of caudal vertebrae in the; colours of the male.

Mantegazza, Prof., on last molar teeth of man; bright colours in male animals; on the ornaments of savages; on the beardlessness of the New Zealanders; on the exaggeration of natural characters by man.

Mantell, W., on the engrossment of pretty girls by the New Zealand chiefs.

Mantis, pugnacity of species of.

Maories, mortality of; infanticide and proportion of sexes; distaste for hairiness amongst men.

Marcus Aurelius, on the origin of the moral sense; on the influence of habitual thoughts.

Mareca penelope.

Marks, retained throughout groups of birds.

Marriage, restraints upon, among savages; influence of, upon morals; influence of, on mortality; development of.

Marriages, early; communal.

Marshall, Dr. W., protuberances on birds' heads; on the moulting of birds; advantage to older birds of paradise.

Marshall, Col., interbreeding amongst Todas; infanticide and proportion of sexes with Todas; choice of husband amongst Todas.

Marshall, Mr., on the brain of a Bushwoman.

Marsupials, development of the nictitating membrane in; uterus of; possession of nipples by; their origin from Monotremata; abdominal sacs of; relative size of the sexes of; colours of.

Marsupium, rudimentary in male marsupials.

Martin, W.C.L., on alarm manifested by an orang at the sight of a turtle; on the hair in Hylobates; on a female American deer; on the voice of Hylobates agilis; on Semnopithecus nemaeus.

Martin, on the beards of the inhabitants of St. Kilda.

Martins deserting their young.

Martins, C., on death caused by inflammation of the vermiform appendage.

Mastoid processes in man and apes.

Maudsley, Dr., on the influence of the sense of smell in man; on idiots smelling their food; on Laura Bridgman; on the development of the vocal organs; moral sense failing in incipient madness; change of mental faculties at puberty in man.

Mayers, W.F., on the domestication of the goldfish in China.

Mayhew, E., on the affection between individuals of different sexes in the dog.

Maynard, C.J., on the sexes of Chrysemys picta.

Meckel, on correlated variation of the muscles of the arm and leg.

Medicines, effect produced by, the same in man and in monkeys.

Medusae, bright colours of some.

Megalithic structures, prevalence of.

Megapicus validus, sexual difference of colour in.

Megasoma, large size of males of.

Meigs, Dr. A., on variation in the skulls of the natives of America.

Meinecke, on the numerical proportion of the sexes in butterflies.

Melanesians, decrease of.

Meldola, Mr., colours and marriage flight of Colias and Pieris.

Meliphagidae, Australian, nidification of.

Melita, secondary sexual characters of.

Meloe, difference of colour in the sexes of a species of.

Memnon, young.

Memory, manifestations of, in animals.

Mental characters, difference of, in different races of men.

Mental faculties, diversity of, in the same race of men; inheritance of; variation of, in the same species; similarity of the, in different races of man; of birds.

Mental powers, difference of, in the two sexes in man.

Menura Alberti, song of.

Menura superba, long tails of both sexes of.

Merganser, trachea of the male.

Merganser serrator, male plumage of.

Mergus cucullatus, speculum of.

Mergus merganser, young of.

Metallura, splendid tail-feathers of.

Methoca ichneumonides, large male of.

Meves, M., on the drumming of the snipe.

Mexicans, civilisation of the, not foreign.

Meyer, on a convoluted body at the extremity of the tail in a Macacus and a cat.

Meyer, Dr. A., on the copulation of Phryganidae of distinct species.

Meyer, Prof. L., on development of helix of ear; men's ears more variable than women's; antennae serving as ears.

Migrations of man, effects of.

Migratory instinct of birds; vanquishing the maternal.

Mill, J.S., on the origin of the moral sense; on the "greatest happiness principle;" on the difference of the mental powers in the sexes of man.

Millipedes.

Milne-Edwards, H., on the use of enlarged chelae of the male Gelasimus.

Milvago leucurus, sexes and young of.

Mimicry.

Mimus polyglottus.

Mind, difference of, in man and the highest animals; similarity of the, in different races.

Minnow, proportion of the sexes in the.

Mirror, behaviour of monkeys before.

Mirrors, larks attracted by.

Mitchell, Dr., interbreeding in the Hebrides.

Mitford, selection of children in Sparta.

Mivart, St. George, on the reduction of organs; on the ears of the lemuroidea; on variability of the muscles in lemuroidea; on the caudal vertebrae of monkeys; on the classification of the primates; on the orang and on man; on differences in the lemuroidea; on the crest of the male newt.

Mobius, Prof., on reasoning powers in a pike.

Mocking-thrush, partial migration of; young of the.

Modifications, unserviceable.

Moggridge, J.T., on habits of spiders; on habits of ants.

Moles, numerical proportion of the sexes in; battles of male.

Mollienesia petenensis, sexual difference in.

Mollusca, beautiful colours and shapes of; absence of secondary sexual characters in the.

Molluscoida.

Monacanthus scopas and M. Peronii.

Monboddo, Lord, on music.

Mongolians, perfection of the senses in.

Monkey, protecting his keeper from a baboon; bonnet-; rhesus-, sexual difference in colour of the; moustache-, colours of the.

Monkeys, liability of, to the same diseases as man; male, recognition of women by; diversity of the mental faculties in; breaking hard fruits with stones; hands of the; basal caudal vertebrae of, imbedded in the body; revenge taken by; maternal affection in; variability of the faculty of attention in; American, manifestation of reason in; using stones and sticks; imitative faculties of; signal-cries of; mutual kindnesses of; sentinels posted by; human characters of; American, direction of the hair on the arms of some; gradation of species of; beards of; ornamental characters of; analogy of sexual differences of, with those of man; different degrees of difference in the sexes of; expression of emotions by; generally monogamous habits of; polygamous habits of some; naked surfaces of; courtship of.

Monogamy, not primitive.

Monogenists.

Mononychus pseudacori, stridulation of.

Monotremata, development of the nictitating membrane in; lactiferous glands of; connecting mammals with reptiles.

Monstrosities, analogous, in man and lower animals; caused by arrest of development; correlation of; transmission of.

Montagu, G., on the habits of the black and red grouse; on the pugnacity of the ruff; on the singing of birds; on the double moult of the male pintail.

Monteiro, Mr., on Bucorax abyssinicus.

Montes de Oca, M., on the pugnacity of male Humming-birds.

Monticola cyanea.

Monuments, as traces of extinct tribes.

Moose, battles of; horns of the, an incumbrance.

Moral and instinctive impulses, alliance of.

Moral faculties, their influence on natural selection in man.

Moral rules, distinction between the higher and lower.

Moral sense, so-called, derived from the social instincts; origin of the.

Moral tendencies, inheritance of.

Morality, supposed to be founded in selfishness; test of, the general welfare of the community; gradual rise of; influence of a high standard of.

Morgan, L.H., on the beaver; on the reasoning powers of the beaver; on the forcible capture of wives; on the castoreum of the beaver; marriage unknown in primeval times; on polyandry.

Morley, J., on the appreciation of praise and fear of blame.

Morris, F.O., on hawks feeding an orphan nestling.

Morse, Dr., colours of mollusca.

Morselli, E., division of the malar bone.

Mortality, comparative, of female and male.

Morton on the number of species of man.

Moschkau, Dr. A., on a speaking starling.

Moschus moschiferus, odoriferous organs of.

Motacillae, Indian, young of.

Moth, odoriferous.

Moths, absence of mouth in some males; apterous female; male, prehensile use of the tarsi by; male, attracted by females; sound produced by; coloration of; sexual differences of colour in.

Motmot, inheritance of mutilation of tail feathers; racket-shaped feathers in the tail of a.

Moult, double; double annual, in birds.

Moulting of birds.

Moults, partial.

Mouse, song of.

Moustache-monkey, colours of the.

Moustaches, in monkeys.

Mud-turtle, long claws of the male.

Mulattoes, persistent fertility of; immunity of, from yellow fever.

Mule, sterility and strong vitality of the.

Mules, rational.

Muller, Ferd., on the Mexicans and Peruvians.

Muller, Fritz, on astomatous males of Tanais; on the disappearance of spots and stripes in adult mammals; on the proportions of the sexes in some Crustacea; on secondary sexual characters in various Crustaceans; musical contest between male Cicadae; mode of holding wings in Castina; on birds shewing a preference for certain colours; on the sexual maturity of young amphipod Crustacea.

Muller, Hermann, emergence of bees, from pupa; pollen-gathering of bees; proportion of sexes in bees; courting of Eristalis; colour and sexual selection with bees.

Muller, J., on the nictitating membrane and semilunar fold.

Muller, Max, on the origin of language; language implies power of general conception; struggle for life among the words, etc., of languages.

Muller, S., on the banteng; on the colours of Semnopithecus chrysomelas.

Muntjac-deer, weapons of the.

Murie, J., on the reduction of organs; on the ears of the Lemuroidea; on variability of the muscles in the Lemuroidea; basal caudal vertebrae of Macacus brunneus imbedded in the body; on the manner of sitting in short-tailed apes; on differences in the Lemuroidea; on the throat-pouch of the male bustard; on the mane of Otaria jubata; on the sub-orbital pits of Ruminants; on the colours of the sexes in Otaria nigrescens.

Murray, A., on the Pediculi of different races of men.

Murray, T.A., on the fertility of Australian women with white men.

Mus coninga.

Mus minutus, sexual difference in the colour of.

Musca vomitoria.

Muscicapa grisola.

Muscicapa luctuosa.

Muscicapa ruticilla, breeding in immature plumage.

Muscle, ischio-pubic.

Muscles, rudimentary, occurrence of, in man; variability of the; effects of use and disuse upon; animal-like abnormalities of, in man; correlated variation of, in the arm and leg; variability of, in the hands and feet; of the jaws, influence of, on the physiognomy of the Apes; habitual spasms of, causing modifications of the facial bones, of the early progenitors of man; greater variability of the, in men than in women.

Musculus sternalis, Prof. Turner on the.

Music, of birds; discordant, love of savages for; reason of power of perception of notes in animals; power of distinguishing notes; its connection with primeval speech; different appreciation of, by different peoples; origin of; effects of.

Musical cadences, perception of, by animals; powers of man.

Musk-deer, canine teeth of male; male, odoriferous organs of the; winter change of the.

Musk-duck, Australian; large size of male; of Guiana, pugnacity of the male.

Musk-ox, horns of.

Musk-rat, protective resemblance of the, to a clod of earth.

Musophagae, colours and nidification of the; both sexes of, equally brilliant.

Mussels opened by monkeys.

Mustela, winter change of two species of.

Musters, Captain, on Rhea Darwinii; marriages amongst Patagonians.

Mutilations, healing of; inheritance of.

Mutilla europaea, stridulation of.

Mutillidae, absence of ocelli in female.

Mycetes caraya, polygamous; vocal organs of; beard of; sexual differences of colour in; voice of.

Mycetes seniculus, sexual differences of colour in.

Myriapoda.

Nageli, on the influence of natural selection on plants; on the gradation of species of plants.

Nails, coloured yellow or purple in part of Africa.

Narwhal, tusks of the.

Nasal cavities, large size of, in American aborigines.

Nascent organs.

Nathusius, H. von, on the improved breeds of pigs; male domesticated animals more variable than females; horns of castrated sheep; on the breeding of domestic animals.

Natural selection, its effects on the early progenitors of man; influence of, on man; limitation of the principle; influence of, on social animals; Mr. Wallace on the limitation of, by the influence of the mental faculties in man; influence of, in the progress of the United States; in relation to sex.

Natural and sexual selection contrasted.

Naulette, jaw from, large size of the canines in.

Neanderthal skull, capacity of the.

Neck, proportion of, in soldiers and sailors.

Necrophorus, stridulation of.

Nectarinia, young of.

Nectariniae, moulting of the; nidification of.

Negro, resemblance of a, to Europeans in mental characters.

Negro-women, their kindness to Mungo Park.

Negroes, Caucasian features in; character of; lice of; fertility of, when crossed with other races; blackness of; variability of; immunity of, from yellow fever; difference of, from Americans; disfigurements of the; colour of new-born children of; comparative beardlessness of; readily become musicians; appreciation of beauty of their women by; idea of beauty among; compression of the nose by some.

Nemertians, colours of.

Neolithic period.

Neomorpha, sexual difference of the beak in.

Nephila, size of male.

Nests, made by fishes; decoration of, by Humming-birds.

Neumeister, on a change of colour in pigeons after several moultings.

Neuration, difference of, in the two sexes of some butterflies and hymenoptera.

Neuroptera.

Neurothemis, dimorphism in.

New Zealand, expectation by the natives of, of their extinction; practice of tattooing in; aversion of natives of, to hairs on the face; pretty girls engrossed by the chiefs in.

Newton, A., on the throat-pouch of the male bustard; on the differences between the females of two species of Oxynotus; on the habits of the Phalarope, dotterel, and godwit.

Newts.

Nicholson, Dr., on the non-immunity of dark Europeans from yellow fever.

Nictitating membrane.

Nidification of fishes; relation of, to colour; of British birds.

Night-heron, cries of the.

Nightingale, arrival of the male before the female; object of the song of the.

Nightingales, new mates found by.

Nightjar, selection of a mate by the female; Australian, sexes of; coloration of the.

Nightjars, noise made by some male, with their wings; elongated feathers in.

Nilghau, sexual differences of colour in the.

Nilsson, Prof., on the resemblance of stone arrow-heads from various places; on the development of the horns of the reindeer.

Nipples, absence of, in Monotremata.

Nitsche, Dr., ear of foetal orang.

Nitzsch, C.L., on the down of birds.

Noctuae, brightly-coloured beneath.

Noctuidae, coloration of.

Nomadic habits, unfavourable to human progress.

Nordmann, A., on Tetrao urogalloides.

Norfolk Island, half-breeds on.

Norway, numerical proportion of male and female births in.

Nose, resemblance of, in man and the apes; piercing and ornamentation of the; very flat, not admired in negroes; flattening of the.

Nott and Gliddon, on the features of Rameses II.; on the features of Amunoph III.; on skulls from Brazilian caves; on the immunity of negroes and mulattoes from yellow fever; on the deformation of the skull among American tribes.

Novara, voyage of the, suicide in New Zealand.

Nudibranch Mollusca, bright colours of.

Numerals, Roman.

Nunemaya, natives of, bearded.

Nuthatch, of Japan, intelligence of; Indian.

Obedience, value of.

Observation, powers of, possessed by birds.

Occupations, sometimes a cause of diminished stature; effect of, upon the proportions of the body.

Ocelli, absence of, in female Mutilidae.

Ocelli of birds, formation and variability of the.

Ocelot, sexual differences in the colouring of the.

Ocyhaps lophotes.

Odonata.

Odonestis potatoria, sexual difference of colour in.

Odour, correlation of, with colour of skin; of moths; emitted by snakes in the breeding season; of mammals.

Oecanthus nivalis, difference of colour in the sexes of.

Oecanthus pellucidus.

Ogle, Dr. W., relation between colour and power of smell.

Oidemia.

Oliver, on sounds produced by Pimelia striata.

Omaloplia brunnea, stridulation of.

Onitis furcifer, processes of anterior femora of the male, and on the head and thorax of the female.

Onthophagus.

Onthophagus rangifer, sexual differences of; variations in the horns of the male.

Ophidia, sexual differences of.

Ophidium.

Opossum, wide range of, in America.

Optic nerve, atrophy of the, caused by destruction of the eye.

Orang-Outan, Bischoff on the agreement of the brain of the, with that of man; adult age of the; ears of the; vermiform appendage of; hands of the; absence of mastoid processes in the; platforms built by the; alarmed at the sight of a turtle; using a stick as a lever; using missiles; using the leaves of the Pandanus as a night covering; direction of the hair on the arms of the; its aberrant characters; supposed evolution of the; voice of the; monogamous habits of the; male, beard of the.

Oranges, treatment of, by monkeys.

Orange-tip butterfly.

Orchestia Darwinii, dimorphism of males of.

Orchestia Tucuratinga, limbs of.

Ordeal, trial by.

Oreas canna, colours of.

Oreas Derbianus, colours of.

Organs, prehensile; utilised for new purposes.

Organic scale, von Baer's definition of progress in.

Orioles, nidification of.

Oriolus, species of, breeding in immature plumage.

Oriolus melanocephalus, coloration of the sexes in.

Ornaments, prevalence of similar; of male birds; fondness of savages for.

Ornamental characters, equal transmission of, to both sexes, in mammals; of monkeys.

Ornithoptera croesus.

Ornithorhynchus, reptilian tendency of; spur of the male.

Orocetes erythrogastra, young of.

Orrony, Grotto of.

Orsodacna atra, difference of colour in the sexes of.

Orsodacna ruficollis.

Orthoptera, metamorphosis of; stridulating apparatus of; colours of; rudimentary stridulating organs in female; stridulation of the, and Homoptera, discussed.

Ortygornis gularis, pugnacity of the male.

Oryctes, stridulation of; sexual differences in the stridulant organs of.

Oryx leucoryx, use of the horns of.

Osphranter rufus, sexual difference in the colour of.

Ostrich, African, sexes and incubation of the.

Ostriches, stripes of young.

Otaria jubata, mane of the male.

Otaria nigrescens, difference in the coloration of the sexes of.

Otis bengalensis, love-antics of the male.

Otis tarda, throat-pouch of the male; polygamous.

Ouzel, ring-, colours and nidification of the.

Ouzel, water-, singing in the autumn; colours and nidification of the.

Ovibos moschatus, horns of.

Ovipositor of insects.

Ovis cycloceros, mode of fighting of.

Ovule of man.

Owen, Prof., on the Corpora Wolffiana; on the great toe in man; on the nictitating membrane and semilunar fold; on the development of the posterior molars in different races of man; on the length of the caecum in the Koala; on the coccygeal vertebrae; on rudimentary structures belonging to the reproductive system; on abnormal conditions of the human uterus; on the number of digits in the Ichthyopterygia; on the canine teeth in man; on the walking of the chimpanzee and orang; on the mastoid processes in the higher apes; on the hairiness of elephants in elevated districts; on the caudal vertebrae of monkeys; classification of mammalia; on the hair in monkeys; on the piscine affinities of the Ichthyosaurians; on polygamy and monogamy among the antelopes; on the horns of Antilocapra Americana; on the musky odour of crocodiles during the breeding season; on the scent-glands of snakes; on the Dugong, Cachalot, and Ornithorhynchus; on the antlers of the red deer; on the dentition of the Camelidae; on the horns of the Irish elk; on the voice of the giraffe, porcupine, and stag; on the laryngeal sac of the gorilla and orang; on the odoriferous glands of mammals; on the effects of emasculation on the vocal organs of men; on the voice of Hylobates agilis; on American monogamous monkeys.

Owls, white, new mates found by.

Oxynotus, difference of the females of two species of.

Pachydermata.

Pachytylus migratorius.

Paget, on the abnormal development of hairs in man; on the thickness of the skin on the soles of the feet of infants.

Pagurus, carrying the female.

Painting, pleasure of savages in.

Palaemon, chelae of a species of.

Palaeornis, sexual differences of colour in.

Palaeornis javanicus, colour of beak of.

Palaeornis rosa, young of.

Palamedea cornuta, spurs on the wings.

Paleolithic period.

Palestine, habits of the chaffinch in.

Pallas, on the perfection of the senses in the Mongolians; on the want of connexion between climate and the colour of the skin; on the polygamous habits of Antilope Saiga; on the lighter colour of horses and cattle in winter in Siberia; on the tusks of the musk-deer; on the odoriferous glands of mammals; on the odoriferous glands of the musk-deer; on winter changes of colour in mammals; on the ideal of female beauty in North China.

Palmaris accessorius, muscle variations of the.

Pampas, horses of the.

Pangenesis, hypothesis of.

Panniculus carnosus.

Pansch, on the brain of a foetal Cebus apella.

Papilio, proportion of the sexes in North American species of; sexual differences of colouring in species of; coloration of the wings in species of.

Papilio ascanius.

Papilio Sesostris and Childrenae, variability of.

Papilio Turnus.

Papilionidae, variability in the.

Papuans, line of separation between the, and the Malays; beards of the; teeth of.

Papuans and Malays, contrast in characters of.

Paradise, Birds of; supposed by Lesson to be polygamous; rattling of their quills by; racket-shaped feathers in; sexual differences in colour of; decomposed feathers in; display of plumage by the male; sexual differences in colour of.

Paradisea apoda, barbless feathers in the tail of; plumage of; and P. papuana; divergence of the females of; increase of beauty with age.

Paradisea papuana, plumage of.

Paraguay, Indians of, eradication of eyebrows and eyelashes by.

Parallelism of development of species and languages.

Parasites, on man and animals; as evidence of specific identity or distinctness; immunity from, correlated with colour.

Parental feeling in earwigs, starfishes, and spiders; affection, partly a result of natural selection.

Parents, age of, influence upon sex of offspring.

Parinae, sexual difference of colour in.

Park, Mungo, negro-women teaching their children to love the truth; his treatment by the negro-women; on negro opinions of the appearance of white men.

Parker, Mr., no bird or reptile in line of mammalian descent.

Parrakeet, young of; Australian, variation in the colour of the thighs of a male.

Parrot, racket-shaped feathers in the tail of a; instance of benevolence in a.

Parrots, change of colour in; imitative faculties of; living in triplets; affection of; colours and nidification of the; immature plumage of the; colours of; sexual differences of colour in; musical powers of.

Parthenogenesis in the Tenthredinae; in Cynipidae; in Crustacea.

Partridge, monogamous; proportion of the sexes in the; Indian; female.

Partridge-"dances."

Partridges, living in triplets; spring coveys of male; distinguishing persons.

Parus coeruleus.

Passer, sexes and young of.

Passer brachydactylus.

Passer domesticus.

Passer montanus.

Patagonians, self-sacrifice by; marriages of.

Patterson, Mr., on the Agrionidae.

Patteson, Bishop, decrease of Melanesians.

Paulistas of Brazil.

Pavo cristatus.

Pavo muticus, possession of spurs by the female.

Pavo nigripennis.

Payaguas Indians, thin legs and thick arms of the.

Payan, Mr., on the proportion of the sexes in sheep.

Peacock, polygamous; sexual characters of; pugnacity of the; Javan, possessing spurs; rattling of the quills by; elongated tail-coverts of the; love of display of the; ocellated spots of the; inconvenience of long tail of the, to the female; continued increase of beauty of the.

Peacock-butterfly.

Peafowl, preference of females for a particular male; first advances made by the female.

Pediculi of domestic animals and man.

Pedigree of man.

Pedionomus torquatus, sexes of.

Peel, J., on horned sheep.

Peewit, wing-tubercles of the male.

Pelagic animals, transparency of.

Pelecanus erythrorhynchus, horny crest on the beak of the male, during the breeding season.

Pelecanus onocrotalus, spring plumage of.

Pelele, an African ornament.

Pelican, blind, fed by his companions; young, guided by old birds; pugnacity of the male.

Pelicans, fishing in concert.

Pelobius Hermanni, stridulation of.

Pelvis, alteration of, to suit the erect attitude of man; differences of the, in the sexes of man.

Penelope nigra, sound produced by the male.

Pennant, on the battles of seals; on the bladder-nose seal.

Penthe, antennal cushions of the male.

Perch, brightness of male, during breeding season.

Peregrine falcon, new mate found by.

Period of variability, relation of, to sexual selection.

Periodicity, vital, Dr. Laycock on.

Periods, lunar, followed by functions in man and animals.

Periods of life, inheritance at corresponding.

Perisoreus canadensis, young of.

Peritrichia, difference of colour in the sexes of a species of.

Periwinkle.

Pernis cristata.

Perrier, M., on sexual selection; on bees.

Perseverance, a characteristic of man.

Persians, said to be improved by intermixture with Georgians and Circassians.

Personnat, M., on Bombyx Yamamai.

Peruvians, civilisation of the, not foreign.

Petrels, colours of.

Petrocincla cyanea, young of.

Petrocossyphus.

Petronia.

Pfeiffer, Ida, on Javan ideas of beauty.

Phacochoerus aethiopicus, tusks and pads of.

Phalanger, Vulpine, black varieties of the.

Phalaropus fulicarius.

Phalaropus hyperboreus.

Phanaeus.

Phanaeus carnifex, variation of the horns of the male.

Phanaeus faunus, sexual differences of.

Phanaeus lancifer.

Phaseolarctus cinereus, taste for rum and tobacco.

Phasgonura viridissima, stridulation of.

Phasianus Soemmerringii.

Phasianus versicolor.

Phasianus Wallichii.

Pheasant, polygamous; and black grouse, hybrids of; production of hybrids with the common fowl; immature plumage of the.

Pheasant, Amherst, display of.

Pheasant, Argus, display of plumage by the male; ocellated spots of the; gradation of characters in the.

Pheasant, Blood-

Pheasant, Cheer.

Pheasant, Eared, length of the tail in the; sexes alike in the.

Pheasant, Fire-backed, possessing spurs.

Pheasant, Golden, display of plumage by the male; age of mature plumage in the; sex of young, ascertained by pulling out head-feathers.

Pheasant, Kalij, drumming of the male.

Pheasant, Reeve's, length of the tail in.

Pheasant, Silver, triumphant male, deposed on account of spoiled plumage; sexual coloration of the.

Pheasant, Soemmerring's.

Pheasant, Tragopan, display of plumage by the male; marking of the sexes of the.

Pheasants, period of acquisition of male characters in the family of the; proportion of sexes in chicks of; length of the tail in.

Philters, worn by women.

Phoca groenlandica, sexual difference in the coloration of.

Phoenicura ruticilla.

Phosphorescence of insects.

Phryganidae, copulation of distinct species of.

Phryniscus nigricans.

Physical inferiority, supposed, of man.

Pickering, on the number of species of man.

Picton, J.A., on the soul of man.

Picus auratus.

Picus major.

Pieris.

Pigeon, female, deserting a weakened mate; carrier, late development of the wattle in; pouter, late development of crop in; domestic, breeds and sub-breeds of.

Pigeons, nestling, fed by the secretion of the crop of both parents; changes of plumage in; transmission of sexual peculiarities in; Belgian, with black-streaked males; changing colour after several moultings; numerical proportion of the sexes in; cooing of; variations in plumage of; display of plumage by male; local memory of; antipathy of female, to certain males; pairing of; profligate male and female; wing-bars and tail-feathers of; supposititious breed of; pouter and carrier, peculiarities of, predominant in males; nidification of; Australian; immature plumage of the.

Pigs, origin of the improved breeds of; numerical proportion of the sexes in; stripes of young; tusks of miocene; sexual preference shewn by.

Pike, American, brilliant colours of the male, during the breeding season.

Pike, reasoning powers of; male, devoured by females.

Pike, L.O., on the psychical elements of religion.

Pimelia striata, sounds produced by the female.

Pinel, hairiness in idiots.

Pintail, drake, plumage of; pairing with a wild duck.

Pintail Duck, pairing with a widgeon.

Pipe-fish, filamentous; marsupial receptacles of the male.

Pipits, moulting of the.

Pipra, modified secondary wing-feathers of male.

Pipra deliciosa.

Pirates stridulus, stridulation of.

Pitcairn island, half-breeds on.

Pithecia leucocephala, sexual differences of colour in.

Pithecia Satanas, beard of; resemblance of, to a negro.

Pits, suborbital, of Ruminants.

Pittidae, nidification of.

Placentata.

Plagiostomous fishes.

Plain-wanderer, Australian.

Planariae, bright colours of some.

Plantain-eaters, colours and nidification of the; both sexes of, equally brilliant.

Plants, cultivated, more fertile than wild; Nageli, on natural selection in; male flowers of, mature before the female; phenomena of fertilisation in.

Platalea, change of plumage in.

Platyblemus.

Platycercus, young of.

Platyphyllum concavum.

Platyrrhine monkeys.

Platysma myoides.

Plecostomus, head-tentacles of the males of a species of.

Plecostomus barbatus, peculiar beard of the male.

Plectropterus gambensis, spurred wings of.

Ploceus.

Plovers, wing-spurs of; double moult in.

Plumage, changes of, inheritance of, by fowls; tendency to analogous variation in; display of, by male birds; changes of, in relation to season; immature, of birds; colour of, in relation to protection.

Plumes on the head in birds, difference of, in the sexes.

Pneumora, structure of.

Podica, sexual difference in the colour of the irides.

Poeppig, on the contact of civilised and savage races.

Poison, avoidance of, by animals.

Poisonous fruits and herbs avoided by animals.

Poisons, immunity from, correlated with colour.

Polish fowls, origin of the crest in.

Pollen and van Dam, on the colours of Lemur macaco.

Polyandry, in certain Cyprinidae; among the Elateridae.

Polydactylism in man.

Polygamy, influence of, upon sexual selection; superinduced by domestication; supposed increase of female births by. In the stickleback.

Polygenists.

Polynesia, prevalence of infanticide in.

Polynesians, wide geographical range of; difference of stature among the; crosses of; variability of; heterogeneity of the; aversion of, to hairs on the face.

Polyplectron, number of spurs in; display of plumage by the male; gradation of characters in; female of.

Polyplectron chinquis.

Polyplectron Hardwickii.

Polyplectron malaccense.

Polyplectron Napoleonis.

Polyzoa.

Pomotis.

Pontoporeia affinis.

Porcupine, mute, except in the rutting season.

Pores, excretory, numerical relation of, to the hairs in sheep.

Porpitae, bright colours of some.

Portax picta, dorsal crest and throat-tuft of; sexual differences of colour in.

Portunus puber, pugnacity of.

Potamochoerus pencillatus, tusks and facial knobs of the.

Pouchet, G., the relation of instinct to intelligence; on the instincts of ants; on the caves of Abou-Simbel; on the immunity of negroes from yellow fever; change of colour in fishes.

Pouter pigeon, late development of the large crop in.

Powell, Dr., on stridulation.

Power, Dr., on the different colours of the sexes in a species of Squilla.

Powys, Mr., on the habits of the chaffinch in Corfu.

Pre-eminence of man.

Preference for males by female birds; shewn by mammals, in pairing.

Prehensile organs.

Presbytis entellus, fighting of the male.

Preyer, Dr., on function of shell of ear; on supernumerary mammae in women.

Prichard, on the difference of stature among the Polynesians; on the connection between the breadth of the skull in the Mongolians and the perfection of their senses; on the capacity of British skulls of different ages; on the flattened heads of the Colombian savages; on Siamese notions of beauty; on the beardlessness of the Siamese; on the deformation of the head among American tribes and the natives of Arakhan.

Primary sexual organs.

Primates, sexual differences of colour in.

Primogeniture, evils of.

Prionidae, difference of the sexes in colour.

Proctotretus multimaculatus.

Proctotretus tenuis, sexual difference in the colour of.

Profligacy.

Progenitors, early, of man.

Progress, not the normal rule in human society; elements of.

Prong-horn antelope, horns of.

Proportions, difference of, in distinct races.

Protective colouring in butterflies; in lizards; in birds; in mammals.

Protective nature of the dull colouring of female Lepidoptera.

Protective resemblances in fishes.

Protozoa, absence of secondary sexual characters in.

Pruner-Bey, on the occurrence of the supra-condyloid foramen in the humerus of man; on the colour of negro infants.

Prussia, numerical proportion of male and female births in.

Psocus, proportions of the sexes in.

Ptarmigan, monogamous; summer and winter plumage of the; nuptial assemblages of; triple moult of the; protective coloration of.

Puff-birds, colours and nidification of the.

Pugnacity of fine-plumaged male birds.

Pumas, stripes of young.

Puppies learning from cats to clean their faces.

Pycnonotus haemorrhous, pugnacity of the male; display of under-tail coverts by the male.

Pyranga aestiva, male aiding in incubation; male characters in female of.