i. 140;

piles of, i. 233.

STORK, black, sexual differences in the bronchi of the, ii. 60; red beak of the, ii. 227.

STORKS, ii. 226, 230; sexual difference in the colour of the eyes of, ii. 128.

STRANGE, Mr., on the Satin Bower-bird, ii. 69.

STRETCH, Mr., on the numerical proportion in the sexes of chickens, i. 306.

_Strepsiceros kudu_, horns of, ii. 255; markings of, ii. 300.

STRIDULATION, by males of _Theridion_, i. 339; of the Orthoptera and Homoptera discussed, i. 360; of beetles, i. 378.

STRIPES, retained throughout groups of birds, ii. 131; disappearance of, in adult mammals, ii. 303.

_Strix flammea_, ii. 105.

STRUCTURE, existence of unserviceable modifications of, i. 153.

STRUGGLE for existence, in man, i. 180, 185.

STRUTHERS, Dr., on the occurrence of the supra-condyloid foramen in the humerus of man, i. 28.

_Sturnella ludoviciana_, pugnacity of the male, ii. 51.

_Sturnus vulgaris_, ii. 105.

SUB-SPECIES, i. 227.

SUFFERING, in strangers, indifference of savages to, i. 94.

SUICIDE, i. 172; formerly not regarded as a crime, i. 94; rarely practised among the lowest savages, i. 94.

SUIDAE, stripes of young, ii. 184.

SUMATRA, compression of the nose by the Malays of, ii. 352.

SUMNER, Archb., man alone capable of progressive improvement, i. 49.

SUN-BIRDS, nidification of, ii. 169.

SUPERSTITIONS, i. 182; prevalence of, i. 99.

SUPERSTITIOUS customs, i. 68.

SUPERCILIARY ridge in man, ii. 316, 318.

SUPERNUMERARY digits, more frequent in men than in women, i. 276; inheritance of, i. 285; early development of, i. 292.

SUPRA-CONDYLOID foramen in the early progenitors of man, i. 206.

SUSPICION, prevalence of, among animals, i. 39.

SULIVAN, Sir B. J., on two stallions attacking a third, ii. 241.

SWALLOW-TAIL Butterfly, i. 393.

SWALLOWS deserting their young, i. 84, 90.

SWAN, black, red beak of the, ii. 227; black-necked, ii. 230; white, young of, ii. 211; wild, trachea of the, ii. 59.

SWANS, ii. 226, 230; young, ii. 208.

SWAYSLAND, Mr., on the arrival of migratory birds, i. 259.

SWINHOE, R., on the common rat in Formosa and China, i. 50; on the sounds produced by the male Hoopoe, ii. 62; on _Dicrurus macrocercus_ and the Spoonbill, ii. 179; on the young of _Ardeola_, ii. 190; on the habits of _Turnix_, ii. 202; on the habits of _Rhynchaea bengalensis_, ii. 203; on Orioles breeding in immature plumage, ii. 214, 215.

_Sylvia atricapilla_, young of, ii. 219.

_Sylvia cinerea_, aerial love-dance of the male, ii. 68.

SYMPATHY, i. 168; among animals, i. 77; its supposed basis, i. 82.

SYMPATHIES, gradual widening of, i. 100.

SYNGNATHOUS fishes, abdominal pouch in male, i. 210.

_Sypheotides auritus_, acuminated primaries of the male, ii. 64; ear-tufts of, ii. 73.

T.

TABANIDAE, habits of, i. 254.

_Tadorna variegata_, sexes and young of, ii. 206.

_Tadorna vulpanser_, ii. 114.

TAHITIANS, i. 183; compression of the nose by the, ii. 352.

TAIL, rudimentary, occurrence of, in man, i. 29; convoluted body in the extremity of the, i. 30; absence of, in man and the higher apes, i. 150, 194; variability of, in species of _Macacus_ and in baboons, i. 150; presence of, in the early progenitors of man, i. 206; length of, in pheasants, ii. 156, 164, 166; difference of length of the, in the two sexes of birds, ii. 164.

TAIT, Lawson, on the effects of natural selection on civilised nations, i. 168.

TANAGER, scarlet, variation in the male, ii. 126.

_Tanagra aestiva_, ii. 180; age of mature plumage in, ii. 213.

_Tanagra rubra_, ii. 126; young of, ii. 220.

_Tanais_, absence of mouth in the males of some species of, i. 255; relations of the sexes in, i. 315; dimorphic males of a species of, i. 328.

TANKERVILLE, Earl, on the battles of wild bulls, ii. 240.

_Tanysiptera_, races of, determined from adult males, ii. 190.

_Tanysiptera sylvia_, long tail-feathers of, ii. 165.

_Taphroderes distortus_, enlarged left mandible of the male, i. 344.

TAPIRS, longitudinal stripes of young, ii. 184, 303.

TARSI, dilatation of front, in male beetles, i. 343.

_Tarsius_, i. 200.

TASMANIA, half-castes killed by the natives of, i. 220.

TATTOOING, i. 232; universality of, ii. 339.

TASTE, in the Quadrumana, ii. 296.

TAYLOR, G. on _Quiscalus major_, i. 307.

TEA, fondness of monkeys for, i. 12.

TEAR-SACKS, of Ruminants, ii. 280.

TEEBAY, Mr., on changes of plumage in spangled Hamburgh fowls, i. 281.

TEETH, rudimentary incisor, in Ruminants, i. 17; posterior molar, in man, i. 25; wisdom, i. 26; diversity of, i. 108; canine, in the early progenitors of man, i. 206; canine, of male mammals, ii. 241; in man, reduced by correlation, ii. 325; staining of the, ii. 339; front, knocked out or filed by some savages, ii. 340.

TEGETMEIER, Mr., on the abundance of male pigeons, i. 306; on the wattles of game-cocks, ii. 98; on the courtship of fowls, ii. 117; on dyed pigeons, ii. 118.

TEMBETA, ii. 341.

TEMPER, in dogs and horses, inherited, i. 40.

TENCH, proportions of the sexes in the, i. 308, 309; brightness of male, during breeding season, ii. 13.

TENEBRIONIDAE, stridulation of, i. 379.

TENNENT, Sir J. E., on the tusks of the Ceylon Elephant, ii. 248, 258; on the frequent absence of beard in the natives of Ceylon, ii. 321; on the Chinese opinion of the aspect of the Cingalese, ii. 345.

TENNYSON, A., on the control of thought, i. 101.

TENTHREDINIDAE, proportions of the sexes in, i. 314; fighting habits of male, i. 364; difference of the sexes in, i. 365.

_Tephrodornis_, young of, ii. 190.

TERAI, i. 237.

_Termites_, habits of, i. 364.

TERNS, white, ii. 228; and black, ii. 230.

TERNS, seasonal change of plumage in, ii. 228.

TERROR, common action of, upon the lower animals and man, i. 39.

_Testudo nigra_, ii. 28.

_Tetrao cupido_, battles of, ii. 50; sexual difference in the vocal organs of, ii. 56.

_Tetrao phasianellus_, dances of, ii. 68; duration of dances of, ii. 100.

_Tetrao scoticus_, ii. 170, 185, 194.

_Tetrao tetrix_, ii. 170, 185, 194; pugnacity of the male. ii. 45.

_Tetrao umbellus_, pairing of, ii. 49; battles of, ii. 50; drumming of the male, ii. 61.

_Tetrao urogalloides_, dances of, ii. 100.

_Tetrao urogallus_, pugnacity of the male, ii. 45.

_Tetrao urophasianus_, inflation of the oesophagus in the male, ii. 57.

_Thamnobia_, young of, ii. 190.

_Thaumalea picta_, display of plumage by the male, ii. 89.

_Thecla_, sexual differences of colouring in species of, i. 389.

_Thecla rubi_, protective colouring of, i. 392.

_Theridion_, i. 337; stridulation of males of, i. 339.

_Theridion lineatum_, variability of, i. 338.

_Thomisus citreus_, and _T. floricolens_, difference of colour in the sexes of, i. 337.

THOMPSON, J. H., on the battles of sperm-whales, ii. 240.

THOMPSON, W., on the colouring of the male char during the breeding season, ii. 14; on the pugnacity of the males of _Gallinula chloropus_, ii. 41; on the finding of new mates by magpies, ii. 103; on the finding of new mates by Peregrine falcons, ii. 104.

THORAX, processes of, in male beetles, i. 370.

THORELL, T., on the proportion of the sexes in spiders, i. 315.

THORNBACK, difference in the teeth of the two sexes of the, ii. 6.

THOUGHTS, control of, i. 101.

THRUSH, pairing with a blackbird, ii. 113; colours and nidification of the, ii. 170.

THRUSHES, characters of young, ii. 185, 269.

THUG, his regrets, i. 94.

THUMB, absence of, in _Ateles_ and _Hylobates_, i. 140.

THURY, M., on the numerical proportion of male and female births among the Jews, i. 301.

_Thylacinus_, possession of the marsupial sack by the male, i. 208.

THYSANURA, i. 348.

TIBIA, dilated, of the male _Crabro cribrarius_, i. 343.

TIBIA and femur, proportions of, in the Aymara Indians, i. 119.

TIERRA del Fuego, marriage-customs of, ii. 373.

TIGER, colours and markings of the, ii. 302.

TIGERS, depopulation of districts by, in India, i. 134.

_Tillus elongatus_, difference of colour in the sexes of, i. 368.

TIMIDITY, variability of, in the same species, i. 40.

TINEINA, proportion of the sexes in, i. 310.

_Tipula_, pugnacity of male, i. 349.

TITS, sexual difference of colour in, ii. 174.

TOADS, ii. 25; male, treatment of ova by some, i. 210; male, ready to breed before the female, i. 260.

TOE, great, condition of, in the human embryo, i. 17.

TOMTIT, blue, sexual difference of colour in the, ii. 174.

TONGA Islands, beardlessness of the natives of, ii. 322, 349.

TOOKE, Horne, on language, i. 55.

TOOLS, flint, i. 183; used by monkeys, i. 51; use of, i. 137.

TOP-KNOTS in birds, ii. 74.

_Tomicus villosus_, proportion of the sexes in, i. 314.

TORTOISE, voice of the male, ii. 331.

TORTURES, submitted to by American savages, i. 95.

_Totanus_, double moult in, ii. 81.

TOUCANS, colours and nidification of the, ii. 171; beaks and ceres of the, ii. 227.

TOWNS, residence in, a cause of diminished stature, i. 115.

TOYNBEE, J., on the external shell of the ear in man, i. 21.

TRACHEA, convoluted and imbedded in the sternum, in some birds,