resembles dung of caterpillars, 58.

CHRYSIDIDAE, how protected, 72.

CHRYSOMELIDAE, similar colouring of two sexes, 114.

CICINDELA, adaptive colour of various species of, 57.

_Cilix compressa_, resembles bird's dung, 63.

CLADOBATES, mimicking squirrels, 107.

CLASSIFICATION, form of true, 6;
circular, inadmissible, 8;
quinarian and circular, of Swainson, 46;
argument from, against Mr. Darwin, 295.

CLIMACTERIS, sexual colouring and nidification of, 243.

COCCINELLIDAE, how protected, 72;
similar colouring of sexes, 114.

COEXISTING varieties, 159.

_Collyrodes lacordairei_, 95.

COLOUR, in animals, popular theories of, 47;
frequent variations of, in domesticated animals, 48;
influenced by need of concealment, 49;
in deserts, 49, 50;
in Arctic regions, 50, 51;
nocturnal, 51;
tropical, 52;
special modifications of, 52;
different distribution of, in butterflies and moths, 58;
of autumnal and winter moths, 62;
white, generally dangerous and therefore eliminated, 66;
why it exists so abundantly although often injurious, 69;
influenced by need of protection, 113;
of female birds, 114;
in relation to nidification of birds, 116;
gaudy colours of many caterpillars, 117;
in nature, general causes of, 126;
local variations of, 173;
sexual differences of, in birds, 239;
in female birds, how connected with their nidification, 240, 246;
more variable than structure or habits, and therefore more easily
modified, 249;
of flowers, as explained by Mr. Darwin, 262;
often correlated with disease, 316.

COMPSOGNATHUS, 300.

_Condylodera tricondyloides_, 97.

CONSCIOUSNESS, origin of, 360;
Professor Tyndall on, 361;
not a product of complex organization, 365.

CORRELATION of growth, 310.

_Corynomalus sp._, 92.

COTINGIDAE, sexual colouring and nidification of, 244.

CRATOSOMUS, a hard weevil, 94.

CRICKETS mimicking sand wasps, 98.

CRYPTODONTIA, 299.

_Cucullia verbasci_, 120.

CURCULIONIDAE, often protected by hard covering, 71;
similar colours of two sexes, 114.

_Cuviera squamata_, 258.

_Cyclopeplus batesii_, 92.

CYNOPITHECUS, 196.

_Cynthia arsinoe_, 172.

DANAIDAE, the subjects of mimicry, 85, 86.

_Danais erippus_, 88;
_chysippus_, 112;
_sobrina_, 179;
_aglaia_, 179;
_tytia_, 180.