Acquired characters. See Hered-
ity.

Adaptation, 40, 55ff. See also
Man.

Agave, 175

Agriculture, 254f. See also Do-
mestic plants; Domestic ani-
mals; Food; Land.

Air, 15, 23, 54. See also Alti-
tude; Wind.
Albino, 326

Alcohol, epilepsy and, 341; hered-
ity and, 316f.; in tropics, 66ƒ.;
selective influence of, 426; sui-
cide and, 429

Alfalfa, 90, 137, 139, 168
Algæ, beginning of life and, 32f.;
in repopulation of devastated
area, 95f.; microorganisms and,
88; symbiosis and, 94
Alloy. See Elements; Metals.
Almond, 167

Alphabet, 480

Alpine race, 384

Altitude, 40ff.

Aluminum, 8, 9, 181ff., 186f., 194

Amputations, 229

Anabolism, 365ff.

Analogy, biological, 451f.
Anatomy, comparative, 287ff.
Anemia, 230

Anesthetics, 228
Angel fish, 52
Aniline dyes, 296ƒ.

Animals, adaptation to environ-
ment, 56ff.; aquatic, food rela-
tions of, 101; destruction of,
120 ff.; distribution of, 48ff.;
domestication of, 113, 122; ef-
fects of destruction of, 141,
144; food habits of, 103f.;
food required by, 88ff.; in geo-
logic time, 292; protection of
domestic, 123ff.; services to
plants, 96. See also Birds;
Plant and animal associations;
Nature, balance of; Domestic
animals; Reptiles.
Antelope, 106, 107, 115, 120
Anthrax, 208, 209, 235

Anthropoids, 288

Antimony, 180

Antiseptics, 228ff.

Ants, Argentine, 132; association