Aid, mutual, among animals, 227 _Ammophila_ mode of stinging prey, 75; of carrying prey, 76; deposition of egg, 77; intelligent behaviour of, 127 _Amœba_, 296 Antlers of deer, 15 Ants, behaviour of, 123; intercommunication of, 198; social communities of, 205 _Aporus_, intelligent behaviour of, 126 Appreciation, germs of, 273 Ardour of male in courtship, 269 _Argyromœba_, instincts of, 79 Arrest of development in egg, 14 Association in coalescent situation, 46 Attention, 242 AUDUBON on American night-hawks, 261 AVEBURY, Lord, on ants, 198; on Van, 200; on aphides and ants, 214; on slave ants, 215; on intelligence of ants, 218 B BALDWIN, Prof. Mark, on organic selection, 37 (note), 115; on functional selection, 163; on imitation, 179 ff.; on projective stage of development, 275 Batesian mimicry, 165 BECHSTEIN on canaries, 262 Bees, homing of, 131; social communities of, 205 Beetle soliciting food from ant, 213 _Bembex_ mode of carrying prey, 76 BETHE, Dr., on instinctive behaviour of ants, 217 BINET, M., on infusoria, 6 Biological value of play, 250; purpose, 294; aspect of animal behaviour, 305 Birch-weevil, leaf-case of, 121 Birds, instinct of, 84 Bison, behaviour of the, 226 BLACKBURN, Mrs. Hugh, on instinct of cuckoo, 90 BLOCKMANN, Dr., on _componotus_, 210 BOLTON on goldfinches’ nests, 136 Bower-bird, observations on, 261, 273 BUCKMAN, Mr. S. S., on speech of children, 203 BUDGETT, Mr. John S., on nest-building, 135 Bullfinch, nest of, 135 C CAMERON, Mr., on mimetic insects in ants’ nest, 212 Canaries’ nest, building of, 135 Canon of interpretation, 270 Capacity, innate, 176 Capuchin monkey, imitation in, 188, 278 CARPENTER, W. B., on water-beetle, 299 Catasetum, fertilization of, 29 Cats, Prof. Thorndike’s experiments on, 147, 184 Causation, idea of, 257 Cell-division in egg, 14 _Cerceris_, instincts of, 74; locality studies of, 129 _Chalicodoma_, parasites of, 78; Fabre’s observations on, 130 Chick swimming, 85; instincts of, 85 ff.; imitation in, 183 Child-study, desirability of, 155, 337 Choice, apparent in Paramecia, 9; in the pairing situation, 266 Ciliary action in Paramecium, 4-10 Circular process (Baldwin), 181 _Clepsine_, behaviour of, 159 Coalescence in conscious situation, 46 Coincident variations defined, 37; survival of, 115, 174 Communities, social, of bees and ants, 205 Companion as centre of special interest, 244 _Componotus_, communities of, 210 Conation and impulse, 187, 235 Concept, nature of, 167 Condensation of experience, 163 Conduct implies motive, 60; and ideal, 278 Congenital responses, 41 Conjugation in Paramecium, 4 Connate instincts, 66, 69 Conscience, ambiguity of word, 281