Animals, the author's attitude in regard to the intelligence of, v, vi; nature of the intelligence of, 1-3; sources of the intelligence of, 4; the sentimental attitude towards, 59-61; emotions and intellect of, 64; language of, 64; curiosity of, 64; altruism of, 65; punishment and discipline among, 65; the three factors that shape their lives, 66; imitation among, 66-70; learning by experience, 70-73; variation in, 73; instinct in, 73-83; incapable of reflection, 77, 78; their knowledge compared with man's, 80, 81; imitation among, not akin to teaching, 83-86; belief in regard to teaching among, 87; play of, 87, 99, 100; communication among, 87-98; fear in, 89, 90; ears of, 95; telepathy among, 96-98; their habits the same everywhere, 101-103; courtship among, 104; stories of poisoning among, 105, 106; stories of trapping and fishing among, 106, 107; individuality among, 118, 119; variation in, 120, 121; ignorance of, 123-125; perceptive intelligence of, 126; partakers of the universal intelligence, 128-130; know what is necessary for them to know, 131; their knowledge inherited, 132; wise in relation to their food and their enemies, 133; and the art of healing, 134; protective coloration of, 138-140; their fear of poison, 140; association of ideas in, 141, 142; emotions of, 143; no ethical sense in, 144, 145; automatism of, 146; and the use of medicine, 147; the truth about them what is wanted, 147-149; the thinking of, instinct in, 151-170; have perceptions but no conceptions, 160; first steps of intelligence in, 161, 162; limitations of intelligence in, 163-168; automatism of trained animals, 166; incredible stories of, 175-184; stories of surgery among, 180-182; true interpretation of seeming acts of reason in, 184-187, 189, 190; absence of language among, 187-189; creatures of routine, 190; the humanization of, 195, 196; nature of their intelligence, 209-230; their minds incapable of improvement, 220-222; the victims of habits, 222; popular notion of teaching among, 233, 234; nature of the homing faculty of, 235; Bostock on the training of wild, 239-242; mimicry among, 248-250; instinct in, 255-261. Antelope, 85. Apple trees, protecting themselves from cattle, 153. Argyll, Duke of, 72. "Atlantic Monthly, The," article in, v, vi, 173. Baboon, 65. Barrington, Daines, 68. Barrus, Dr. Clara, her description of the woodcock's song and song flight, 43. Bean, the, intelligence of, 1, 2. Bear, a caged, 76. Bear, black, 260. Beaver, 166, 167; nature of his intelligence, 209-211. Beebe, C. William, on instinct and reason in birds, 215-217. Bees, 24. Belief, scientific grounds for, 173-179.