[CHAPTER VII]
Reason
Definition of reason—Origin of instincts—Instances of intelligent ratiocination—In the bee—The wasp—The ant—Mental degeneration in ants occasioned by the habit of keeping slaves—The honey-making ant filling an artificial trench—Other evidences of reason in the insect—Termes—Division of labor—The king and queen—Bravery of soldier ants—Overseer and laborers—Blind impulse and intelligent ideation—Harvester ants—Their habits and intelligence—Their presence in Arkansas believed to be unique—Animals able to count—This faculty present in the mason wasps—Experiments—Certain birds able to count—Also dogs and mules—Cat recognizing the lapse of time—Monkey's ability in computing—Huber's experiment with glass slip and bees—Kirby and Spence's comment—Summary. 147
[CHAPTER VIII]
Auxiliary Senses
The color-changing sense and "homing instinct" so-called—These faculties not instincts but true senses—The chromatic function—Tinctumutation—Chromatophores and their function—Various theories—Experiments of Paul Bert with axolotls—Semper's contention—The difference between plant coloring and animal coloring—Effects of light—Experiments with newts—Lister's observations—Pouchet's experiments—Sympathetic nerves—Author's experiments with frogs—The sense-centre of tinctumutation—Effects of atropia—Experiments with fish—With katydid—The "homing instinct" a true sense—Evidences of the sense in a water-louse—Author's experiments with snails—Location of sense-centre in snails—Evidences of the homing sense in the limpet—In beetles—In fleas—In ants—In snakes—In birds—In fish. 181
[CHAPTER IX]
Letisimulation
Not confined to any family, order, or species of animals—Death-feigning by rhizopods—By fresh-water annelids—By the larvæ of butterflies and beetles—By free-swimming rotifers—By snakes—By the itch insect (Sarcoptes hominis)—By many of the Coleoptera—The common "tumble bug" (Canthon Lævis) a gifted letisimulant—The double defence of the pentatomid, "stink-bug"—Reason coming to the aid of instinct—Death-feigning an instinct—Feigning of death by ants—By a hound—Not instinctive in the dog and cat—The origin of this instinct—Summary. 202