Acclimatization, 319.
Acorn, 24.
Acracids, 160.

Adaptation, definition of, I.
Adjustments, individual, 12.
Agassiz, 1, 44, 61.
Agelæus, 173.

Alcohol, 13.

Algæ, red, 9.
Alkaloids, 13.

Allen, 173, 307-310.
Allolobophora, 380.
Alpheus, 344.
Ammophila, 5.
Ammotragus, 208.
Ampelopsis, 403.
Amphimixis, 448-449.
Amphioxus, 399.
Ancon race, 315-316.
Angiostomum, 422.
Anguillidæ, 320.
Annelids, 19, 20.

Anolis, 10, 194.

Ant-eater, 227, 228.

Antelope, 6, 206, 208.
Antitoxin, 14.

Ants, 141-146, 354, 386, 407.

Aphids, 384-386, 419, 426.
Apus, 418.

Archeopteryx, 41, 42, 53, 54.
Ardea, 200.

Argus pheasant, 199.

Aristolochia Clematitis, 10, II, 12.

Law of Biogenesis, 30.

Leaf, resemblance to, 7.

Leaves, closing of, 11.

Leeches, 417.
Leguminosa, 124.
Leidy, 46.

Length of life, 20.

Lenhossek, 435.
Leopard, 209.
Lepidoptera, 172.
Leptothrix, 320.
Leucophys, 442.
Lichen, 9.
Lillie, 72.

Limbs of vertebrates, 46.
Linaria, 401.
Linnæan species, 85.
Linnæus, 191.
Lion, 6.

Lizards, 7, 16, 17, 193.
Lobelia, 148.

Lobster, 343.

Lockwood, 138.
Locusts, 188.

Loeb, 383-392, 447.

Lomaria, 290.
Lowell lectures, 61.
Lumbriculus, 15.

Luminous organs, 133.
Lymnæa, 305, 322.
Lythrum, 365-370.

Machines, 26, 27, 28.

McIntosh, 176.

McNeill, 204.

Macropus, 192.
Malva, 401.

Mammalia, origin, 54, 202.

Minnow, 16.
Minot, 433.

Mirabilis, 149, 150.
Mivart, 136, 137.

Mole, 1, 2, 18, 227.
Mole-cricket, I, 2.
Molothrus, 140.
Monkeys, 207, 208.
Mons, Van, 332.
Montgomery, 432.
Moor-hen, 453-

Moquin-Tandon, 303.
Morton, Lord, 238.
Moschus, 206.

Moths, 184, 387, 388.
Moussu, 257.
Mozart, 218.
Mulberry, 313.
Müller, 182, 188.
Müller, Fritz, 148.
Muscles, 12.

Mycetes, 205.
Myzostomum, 422.