i. 242;

purpose of, in lepidoptera, i. 399; relation of, to sexual functions, in fishes, ii. 14; difference of, in the sexes of snakes, ii. 29; sexual differences of, in lizards, ii. 36; influence of, in the pairing of birds of different species, ii. 115; relation of, to nidification, ii. 167, 172; sexual differences of, in mammals, ii. 286, 294; recognition of, by quadrupeds, ii. 295; of children, in different races of man, ii. 318; of the skin in man, ii. 381.

COLOURS, admired alike by man and animals, i. 64; bright, due to sexual selection, i. 322; bright, among the lower animals, i. 322, 323; bright, protective to butterflies and moths, i. 395; bright, in male fishes, ii. 7, 13; transmission of, in birds, ii. 159.

COLQUHOUN, example of reasoning in a retriever, i. 48.

_Columba passerina_, young of, ii. 188.

_Colymbus glacialis_, anomalous young of, ii. 211.

COMB, development of, in fowls, i. 295.

COMBS and wattles in male birds, ii. 98.

COMMUNITY, preservation of variations useful to the, by natural selection, i. 155.

COMPOSITAE, gradation of species among the, i. 227.

COMTE, C., on the expression of the ideal of beauty by sculpture, ii. 380.

CONDITIONS of life, action of changed, upon man, i. 113; influence of, on plumage of birds, ii. 196.

CONDOR, eyes and comb of the, ii. 129.

CONJUGATIONS, origin of, i. 61.

CONSCIENCE, i. 91, 104; absence of, in some criminals, i. 92.

CONSTITUTION, difference of, in different races of men, i. 216.

CONSUMPTION, liability of _Cebus Azarae_ to, i. 12; connexion between complexion and, i. 244.

CONVERGENCE, i. 230.

COOING of pigeons and doves, ii. 60.

COOK, Capt., on the nobles of the Sandwich Islands, ii. 356.

COPE, E. D., on the dinosauria, i. 204; on the origin of genera, ii. 215.

_Cophotis ceylanica_, sexual differences of, ii. 32, 36.

_Copris_, i. 370.

_Copris Isidis_, sexual differences of, i. 369.

_Copris lunaris_, stridulation of, i. 380.

CORALS, bright colours of, i. 322.

CORAL-SNAKES, ii. 31.

_Cordylus_, sexual difference of colour in a species of, ii. 36.

CORFU, habits of the chaffinch in, i. 307.

CORNELIUS, on the proportions of the sexes in _Lucanus Cervus_, i. 313.

CORPORA WOLFFIANA, i. 207; agreement of, with the kidneys of fishes, i. 16.

CORRELATED variation, i. 130.

CORRELATION, influence of, in the production of races, i. 247.

CORSE, on the mode of fighting of the elephant, ii. 257.

_Corvus corone_, ii. 104.

_Corvus graculus_, red beak of, ii. 227.

_Corvus pica_, nuptial assembly of, ii. 102.

_Corydalis cornutus_, large jaws of the male, i. 342.

_Cosmetornis_, ii. 181.

_Cosmetornis vexillarius_, elongation of wing-feathers in, ii. 73, 97.

COTINGIDAE, sexual differences in, i. 269; coloration of the sexes of, ii. 177; resemblance of the females of distinct species of, ii. 192.

_Cottus scorpius_, sexual differences in, ii. 9.

COUNTING, origin of, i. 181; limited power of, in primeval man, i. 234.

COURAGE, variability of, in the same species, i. 40; universal high appreciation of, i. 95; importance of, i. 162; a characteristic of men, ii. 328.

COURTSHIP, greater eagerness of males in, i. 272; of fishes, ii. 2; of birds, ii. 50, 100.

COW, winter change of the, ii. 299.

CRAB, devil, i. 332.

CRAB, shore, habits of, i. 331.

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

CRABS, proportions of the sexes in, i. 315.

CRANZ, on the inheritance of dexterity in seal-catching, i. 117.

CRAWFURD, on the number of species of man, i. 226.

_Crenilabrus massa_ and _C. melops_, nests built by, ii. 19.

CREST, origin of, in Polish fowls, i. 284.

CRESTS, of birds, difference of, in the sexes, ii. 189; dorsal hairy, of mammals, ii. 282.

CRICKET, field-, stridulation of the, i. 353; pugnacity of male, i. 360.

CRICKET, house-, stridulation of the, i. 352, 354.

CRICKETS, sexual differences in, i. 361.

CRIOCERIDAE, stridulation of the, i. 379.

CRINOIDS, complexity of, i. 61.

CROAKING of frogs, ii. 27.

CROCODILES, musky odour of, during the breeding season, ii. 29.

CROCODILIA, ii. 28.

CROSSBILLS, characters of young, ii. 184.

CROSSES in man, i. 225.

CROSSING of races, effects of the, i. 241.

_Crossoptilon auritum_, ii. 93, 166, 196; adornment of both sexes of, i. 290; sexes alike in, ii. 178.

CROTCH, G. R., on the stridulation of beetles, i. 379, 382; on the stridulation of _Heliopathes_, i. 383; on the stridulation of _Acalles_, i. 384.

CROW Indians, long hair of the, ii. 348.

CROW, young of the, ii. 209.

CROWS, ii. 226; vocal organs of the, ii. 55; living in triplets, ii. 106.

CROWS, carrion, new mates found by, ii. 104.

CROWS, Indian, feeding their blind companions, i. 77.

CRUELTY of savages to animals, i. 94.

CRUSTACEA, amphipod, males sexually mature while young, ii. 215; parasitic, loss of limbs by female, i. 255; prehensile feet and antennae of, i. 256; male, more active than female, i. 272; parthenogenesis in, i. 315; secondary sexual characters of, i. 328; auditory hairs of, ii. 333.

CRYSTAL worn in the lower lip by some Central African women, ii. 341.

CUCKOO fowls, i. 294.

CULICIDAE, i. 254, 349.

CULLEN, Dr., on the throat-pouch of the male bustard, ii. 58.

CULTIVATION of plants, probable origin of, i. 167.

CUPPLES, Mr., on the numerical proportion of the sexes in dogs, sheep, and cattle, i. 304, 305; on the Scotch deerhound, ii. 261; on sexual preference in dogs, ii. 271, 272.

CURCULIONIDAE, sexual difference in length of snout in some, i. 255; hornlike processes in male, i. 374; musical, i. 378, 379.

CURIOSITY, manifestations of, by animals, i. 42.

CURLEWS, double moult in, ii. 80.

CURSORES, comparative absence of sexual differences among the, i. 269.

CURTIS, J., on the proportion of the sexes in _Athalia_, i. 314.

CUVIER, F., on the recognition of women by male quadrumana, i. 13.

CUVIER, G., views of, as to the position of man, i. 190; on instinct and intelligence, i. 37; on the number of caudal vertebrae in the mandrill, i. 150; on the position of the seals, i. 190; on _Hectocotyle_, i. 325.

_Cyanecula suecica_, sexual differences of, ii. 195.

_Cyanalcyon_, sexual difference in colours of, ii. 173; immature plumage of, ii. 188.

_Cychrus_, sounds produced by, i. 382.

_Cycnia mendica_, sexual difference of colour in, i. 398.

_Cygnus ferus_, trachea of, ii. 59.

_Cygnus olor_, white young of, ii. 211.

_Cyllo Leda_, instability of the ocellated spots of, ii. 133.

_Cynanthus_, variation in the genus, ii. 125.

CYNIPIDAE, proportions of the sexes in, i. 314.

_Cynocephalus_, difference of the young, from the adult, i. 13; male, recognition of women by, i. 13; polygamous habits of species of, i. 266.

_Cynocephalus chacma_, i. 41.

_Cynocephalus gelada_, i. 51.

_Cynocephalus hamadryas_, i. 51; sexual difference of colour in, ii. 291.

_Cynocephalus leucophoeus_, colours of the sexes of, ii. 292.

_Cynocephalus mormon_, colours of the male, ii. 292, 296, 310.

_Cynocephalus porcarius_, mane of the male, ii. 267.

_Cypridina_, proportions of the sexes in, i. 315.

CYPRINIDAE, proportion of the sexes in the, i. 308.

CYPRINIDAE, Indian, ii. 17.

CYPRINODONTIDAE, sexual differences in the, ii. 7, 9.

_Cyprinus auratus_, ii. 16.

_Cyprinus phoxinus_, spawning of, ii. 15.

_Cypris_, relations of the sexes in, i. 315.

_Cystophora cristata_, hood of, ii. 278.

D.

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

_Dacelo Gaudichaudi_, young male of, ii. 188.

DAL-RIPA, a kind of ptarmigan, i. 306.

_Damalis albifrons_, peculiar markings of, ii. 301.

_Damalis pygarga_, peculiar markings of, ii. 300.

DAMPNESS of climate, supposed influence of, on the colour of the skin, i. 116, 242.

_Danaidae_, i. 387.

DANCES of birds, ii. 68.

DANCING, i. 232.

DANIELL, Dr., his experience of residence in West Africa, i. 245.

DARFUR, protuberances artificially produced in, ii. 339.

DARWIN, F., on the stridulation of _Dermestes murinus_, i. 379.

_Dasychira pudibunda_, sexual difference of colour in, i. 398.

DAVIS, A. H., on the pugnacity of the male stag-beetle, i. 375.

DAVIS, J. B., on the capacity of the skull in various races of men,