SNAKE, love of young in, 140; author's experiment in testing parental affection of, 140; sense of direction and "homing instinct" in, 198; author's observations of "homing instinct" in, 198. SOLE, the origin of unilateral eyes in the, 9. SONG-SPARROW, memory of individuals in, 77; parental affection in, 143. SPANIEL, a laughing, 89. SPIDER, memory in, 72; recognition of individuals by, 73; love of music in the, 108; author's experiments with piano on, 108; author's experiments with pipe organ on, 109; Reclain's observations on the love of music in, 109; decorative instinct present in, 110; peculiar web spun by, 110; parental affection in, 135; author's experiment in testing parental love of, 135; use of implement (pebble anchor) by, 222. SQUIRREL, memory in the, 70. STENTOR POLYMORPHUS, nervous system of, 46; observations of and experiments with, 47; conscious determination in, 47; ganglia of, 47. STRONGALOGNATHUS, degeneration caused by the habit of slave-making in, 155, 156, 157. T TABANUS ATRATUS, balancers of, 33; loss of equilibrium in, 33; anatomy of balancers of, 34; auditory hairs of, 34. TERMES, kinds of individuals in a colony of, 161; number of eggs laid by queen of, 162; size of gravid queen, 162; New Mexican, 163; soldiers and workers of, 163; instincts and reasoning powers of, 164. TERRIER, love of music in, 113; musical discrimination in, 113; abstract ideation in, 216. TINCTUMUTATION, definition of, 182; location of color-changing sense centre in, 183. TOAD, memory in the, 87; a performing, 87; parental affection in the Surinam, 140. TRITICUM REPENS, sick dogs medicate themselves with, 220. TURKEY, memory of individuals in the, 76; recognition of property rights by the, 221. V VANESSA, tinctumutation in the larva of, 192. VIPER, death-feigning in the, 207. VOLITION, definition of conscious, 39; physiological aspect of, 40. W WASP, memory in the, 62; author's experiments in testing memory in the, 63, 69; memory of kindred in the, 65, 69; memory of locality and of events in the, 85; knowledge derived from a single experience by a, 85; length of life in the mud-dauber, 138; evidence of reason in the mud-dauber, 149, 150; psychic actualities of easy acquirement in the ant, the bee, and the, 151; faculty of computing in the mason, 169; author's experiments in testing the computing faculty in the, 170; method of preparing food for the male and female grubs used by the mason, 170. WATER-LOUSE, sense of direction in the, 194. WREN, distress and grief evinced by, 93; recognition of individuals by, 93; gratitude shown by, 94. * * * * * ECONOMICS. BY EDWARD THOMAS DEVINE, Ph.D.,