The Descent of Man, and Selection in Relation to Sex

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.