I.

Ibla, 148. Icebergs transporting seeds, 363. Increase, rate of, 63. Individuals, numbers favourable to selection, 102. ----, many, whether simultaneously created, 355. 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.

J.

Japan, productions of, 372. Java, plants of, 375. Jones, Mr. J. M., on the birds of Bermuda, 391. Jussieu on classification, 417.

K.

Kentucky, caves of, 137. Kerguelen-land, flora of, 381, 399. Kidney-bean, acclimatisation of, 142. Kidneys of birds, 144. Kirby on tarsi deficient in beetles, 135. Knight, Andrew, on cause of variation, 7. Kölreuter on the barberry, 98. ---- on sterility of hybrids, 246. ---- on reciprocal crosses, 258. ---- on crossed varieties of nicotiana, 271. ---- on crossing male and hermaphrodite flowers, 451.