394 MENTAL EVOLUTION IN ANIMALS. 



House-sparrow, nidification of the, 210. 



Houzeau, on stridulation, 86 ; on birds dreaming, 149 ; on mistaken in- 

 stincts, 167 ; on inability of infants to localize pain, 326. 



Howitt, A. W., on homing faculty of horses and cattle, 290. 



Huber, on instincts of bees, 168, 203-9. 



Huber, P., on instincts of a caterpillar, 179. 



Huggins, Dr., on sense of musical pitch in a dog, 94 ; on inherited antipathy 

 of a dog to butchers, 187. 



Humboldt, on individual disposition in monkeys, 188. 



Humming-bird hawk-moth, mistaken instinct of the, 167. 



Hunger, sense of, 95, 



Hunter, John, on tricks of manner being inherited, 185. 



Hurdis, on migration of the golden plover, 286. 



Hutchinson, Colonel, on inherited tendency to bark in sporting dogs, 236. 



Hutton, Captain, on wildness of the hybrid between the tame and wild goat, 

 199 ; on wildness of chickens reared from wild Gallus hankiva, 232 ; on 

 migration, 288. 



Huxley, Professor T. H., on evolution of sense-organs, 104. 



Syclrozoa, nerve-tissues in, 24. 



Hyaena, not burrowing in South Africa, 244. 



Hylohates agilis, its sense of musical pitch, 93. 



Symenoptera. See Ants and Bees. 



Hypnotism, reaction-time under influence of, 138 ; of animals, 308-11. 



Hyrax, dreaming in the, 149. 



Ichneumon, instincts of the, 166. 



Ideas, association of, 37-8, 111-24; definition of, 118; composite, ana- 

 logous to muscular coordinations, 42-4. 



Idiots, size of brain of, in relation to intelligence, 45; personal equation of, 

 138 ; tricks of manner shown by, 181 ; automatic actions of, 193 ; imita- 

 tive actions of, 225. 



Industry, 341. 



Imagination, 142-58 ; analysis of, 142-4 ; stages and evolution of, 144-5 ; 

 stages of, as occurring in difierent animals, 145-54. 



Imitation, effects of, on formation of instinct, 220-9; by hive-bees of 

 humble bees, 220-1 ; by dogs of other dogs, 221 ; by dogs of cats, 223- 

 4 ; by birds of one another's songs, and of articulate speech, 222-3 ; by 

 monkeys, children, savages, and idiots, 225 ; by young birds in nidifica- 

 tion suggested by Mr. Wallace, 225-6 ; of parents by young of sundry 

 animals, 226-9. 



Incubation, instinct of, 177. 



Infant, consciousness in the, 77 ; preferring sweet tastes, and remembering 

 taste 'of milk, 114-16; earliest power of associating ideas, 120-1, and 

 mental images, 152 ; when spoon-fed forgetting to suck, 170, 180 ; learn- 

 ing to balance the head, &c., 175-6 ; imitative movements of the, 225 ; 

 inability of the, to localize pain, 326 ; emotions of fear and surprise in 

 the, 342. 



Inference. See Reason. 



Infusoria. See Protozoa. 



Injury, feigning of, by animals, 316-17. 



Insects, eyes of, 84-5 ; colour-sense of, 99 ; imagination of, 145-6 ; instmcts 

 of, 165-8, 179, 201-2, 203-9, 220-1, 246, 277-81, 285-6, 290, 293-5, 

 297-309 J emotions of, 344. 



