IV TIME RELATIONS OF TASTE QUALITIES 55 The Inertia of the Taste Organs—Reaction Time to Taste Stimuli—Determinants of Reaction Time to Taste. V THE SENSE ORGAN OF TASTE 60 Comparison with other Sense Organs—The Salivary Glands and Their Activity—The Tongue: Its Muscles and Covering Membranes—Classification of Papillæ—The Determination of the Taste Areas. VI SENSORY ELEMENTS OF THE TASTE MECHANISM 78 Taste Buds and Their General Characteristics—Supporting Cells, Gustatory Cells, and Nerve Filaments—Relations Among the Structures within the Taste Bud—The Sensory Nerves of Taste—The Cerebral Taste Centers. VII TASTE-PRODUCING SUBSTANCES 92 Adequate and Inadequate Stimuli—Adequate Taste Stimuli—Inadequate Taste Stimuli. VIII THE FUNCTION OF THE TASTE MECHANISM 103 The Function of Tongue and Salivary Glands—The Function of the Taste Buds. IX THE DEVELOPMENT OF TASTE IN THE 116 INDIVIDUAL Development Before Birth—Development of Taste in Infancy and Childhood—Taste in the Adult—Structural and Functional Differences Among Individuals—Individual Differences Due to Pathological Changes—Racial Differences in the Structure and Function of the Taste Organs. X EVOLUTION OF TASTE 128 Sensitivity of the Unicellular Organisms—“The Chemical Sense”—Chemical Sense in Fishes—Land-Dwelling Animals. XI GUSTATORY IMAGINATION AND MEMORY 144 The Nature and Frequency of Mental Images—Mental Images of Taste—Taste in Dreams and in Hallucinations. XII UNUSUAL AND ABNORMAL TASTE EXPERIENCES 151 Gustatory Hallucinations and Auræ—Partial and Complete Ageusia—Taste Hallucinations of the Insane—Synæsthesias of Taste—Perversions of Taste. XIII FOOD AND FLAVOR 158 The Biological Rôle of Taste—Taste and Digestion—Experimental Evidences—The Function of Taste in the Organic Economy.