Increase, rate of, 63.
Individuals:
numbers favourable to selection, 102.
many, whether simultaneously created, 356.
Inheritance:
laws of, 12.
at corresponding ages, 14, 86.
Insects:
colour of, fitted for habitations, 84.
sea-side, colours of, 132.
blind, in caves, 138.
luminous, 193.
neuter, 236.
Instinct, 207.
Instincts, domestic, 213.
Intercrossing, advantages of, 96.
Islands, oceanic, 388.
Isolation favourable to selection, 104.
Japan, productions of, 372.
Java, plants of, 375.
Jones, Mr. J. M., on the birds of Bermuda, 391.
Jussieu on classification, 417.
Kentucky, caves of, 137.
Kerguelen-land, flora of, 381, 399.
Kidney-bean, acclimatisation of, 142.
385