Colobus, absence of the thumb.
Colombia, flattened heads of savages of.
Colonists, success of the English as.
Coloration, protective, in birds.
Colour, supposed to be dependent on light and heat; correlation of,
with immunity from certain poisons and parasites; purpose of, in
lepidoptera; relation of, to sexual functions, in fishes; difference
of, in the sexes of snakes; sexual differences of, in lizards;
influence of, in the pairing of birds of different species; relation
of, to nidification; sexual differences of, in mammals; recognition of,
by quadrupeds; of children, in different races of man; of the skin in
man.
Colours, admired alike by man and animals; bright, due to sexual
selection; bright, among the lower animals; bright, protective to
butterflies and moths; bright, in male fishes; transmission of, in
birds.
Colquhoun, example of reasoning in a retriever.
Columba passerina, young of.
Colymbus glacialis, anomalous young of.
Comb, development of, in fowls.
Combs and wattles in male birds.
Community, preservation of variations useful to the, by natural
selection.
Complexion, different in men and women, in an African tribe.
Compositae, gradation of species among the.
689