i. 158;

probably perfected through natural selection, i. 160.

INTELLIGENCE, Mr. H. Spencer on the dawn of, i. 37.

INTEMPERANCE, no reproach among savages, i. 96; its destructiveness, i. 172.

INTOXICATION in monkeys, i. 12.

_Iphias glaucippe_, i. 394.

IRIS, sexual difference in the colour of the, in birds, ii. 72, 128.

ISCHIO-PUBIC muscle, i. 127.

_Ithaginis cruentus_, number of spurs in, ii. 46.

_Iulus_, tarsal suckers of the males of, i. 340.

J.

JACKALS learning to bark from dogs, i. 44.

JACK-SNIPE, coloration of the, ii. 226.

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

JAEGER, Dr., on the difficulty of approaching herds of wild animals,