AXOLOTL, color-changing in, 184; Paul Bert's experiments with, 184; Semper's experiments with, 184; Kölliker's experiments with, 184. B BALANCERS, of _Tabanus atratus_, 34; of _Chrysops niger_, 33; of _Diplosis resinicola_, 33. BASCANION CONSTRICTOR, recognition of individuals by, 75; bird decorates its nest with skin of, 127. BASS, parental affection in, 138; homing sense in black, 200. BECKIA, ants domesticate and pet, 126. BIRD, memory of individuals in, 76, 77; gratitude in, 77, 93; homing sense in, 199. BOMBARDIER BUG, death-feigning in, 211. BRACHIONUS, actinophrys captures, 7. BRACHIONUS URCEOLARIS, death-feigning in, 206. BUMBLEBEE, revenge and anger in, 71; recognition of a certain dog by, 71. BURYING BEETLE, homing sense in, 197. BUTTERFLY, suitable food for larva selected by, 103; age of tropical, 137; Miranda's observations, 137, 138. C CALOTIS, third eye of, 27. CANTHON LÆVIS, death-feigning in, 210. CAPUCHIN MONKEY, surgical operation on a, 95; faith in man's ability to aid evinced by a, 96. CARABIDÆ, auditory vesicles of, 37; memory of locality in, 64. CAT, pride of offspring in a male, 142; idea of time shown by a, 177. CATFISH, parental affection in, 138, 139. CERAMBYX, sense of hearing in, 36; Will's experiment with, 36. CHACMA, cat chosen as friend by, 83; author's test for memory of individuals in, 84. CHAMELEON, educated, 75; recognition of individual by, 75. CHICK, pigment cells in embryonic, 186, 187. CHIMPANZEE, laughter and smiles evinced by, 89; faculty of computing in, 177; recognition of property rights by, 221. CHRYSOPS NIGER, balancers of, 33; organs of hearing in, 33. CICINDELIDÆ, auditory vesicles of, 37; memory of locality in, 64. CLAVIGER FOVEOLATUS, ants make a pet of, 73. COCCINELLÆ, peculiar assemblages of female, 126, 127. COCK, friendship between a drake and a, 78; fondness for violin music in a, 122. CONSCIOUSNESS, definition of, 43; time element in, 44; the probable location of active, 216; the probable location of the sub-liminal, 216. CORYDALIS, auditory rods of, 30. COW, dog the guardian and friend of a, 80. CRAB, Pouchet's experiment on the chromatophores of, 189. CRAYFISH, eyes of, 21; power of vision in, 23; pugnacity of, 23. CRICKET, ears of, 31. CYMOTHOE, eyes of fresh-water, 13. D DETERMINATION, the origin of conscious, 40. DINOCHARIS POCILLUM, death-feigning in, 206. DIPLOSIS RESINICOLA, balancers of, 33. DIPTERA, ears of, 33; love of pastime in, 125. DOG, cow chosen as a friend by a, 78; laughter in, 90; fondness for certain musical keys in the, 112; author's experiments with the, 113; origin of musical discrimination in the, 114; knowledge of the echo in the, 115; author's observations of an echo-loving, 115; parental affection in the, 141; abstract idea of numbers in the, 173, 174; phenomenon of dreaming in the, 218; medication by sick, 220.