Intellectual faculties, their influence on natural selection in man; probably perfected through natural selection.
Intelligence, Mr. H. Spencer on the dawn of.
Intemperance, no reproach among savages; its destructiveness.
Intoxication in monkeys.
Iphias glaucippe.
Iris, sexual difference in the colour of the, in birds.
Ischio-pubic muscle.
Ithaginis cruentus, number of spurs in.
Iulus, tarsal suckers of the males of.
Jackals learning from dogs to bark.