TABLE OF CONTENTS. xix 



The Cortical Thermic Center, 788 



Physiological Topography of the Surface of the Cerebrum in Man 791 



The Basal Ganglia of the Cerebrum, The Midbrain. Forced Movements. 



Other Cerebral Functions, 802 



Functions of the Cerebellum, 807 



Protective and Nutritive Apparatus of the Brain 809 



Comparative. Historical, 811 



PHYSIOLOGY OF THE ORGANS OF SPECIAL SENSE. 



Introductory Remarks 813 



THE VISUAL APPARATUS. 



Preliminary Anatomical and Histological Observations. The Intraocular 



Pressure, 815 



Preliminary Dioptric Considerations, 823 



Application of Dioptric Laws to the Eye. Construction of the Retinal 



Image. The Ophthalmometer. Erect Images, 829 



Accommodation of the Eye, 83 1 



Refractive Power of the Normal Eye. Anomalies of Refraction, 835 



Measure of the Power of Accommodation, 837 



Spectacles, 839 



Chromatic and Spherical Aberration. Defective Centering of the Refracting 



Surfaces. Astigmatism 840 



The Iris, 841 



Entoptic Phenomena. Subjective Optical Manifestations 844 



Illumination of the Eye, and the Ophthalmoscope, 847 



The Function of the Retina in Vision, 850 



Perception of Colors, 856 



Color-blindness: Its Practical Importance, 860 



Time-relations of Retinal Stimulation. Positive and Negative After- 

 images. Irradiation. Contrast, 862 



Ocular Movements and Ocular Muscles, 866 



Binocular Vision, 870 



Single Vision. Identical Retinal Points. Horopter. Suppression of 



Double Images, 871 



Stereoscopic Vision. Judgment of Solidity, 873 



Estimation of Size and of Distance. False Estimates of Size and Direction, 877 



Organs for the Protection of the Eye 879 



Comparative. Historical, 881 



THE AUDITORY APPARATUS. 



Plan of the Structure of the Ear, 885 



Preliminary Physical Considerations, ... 886 



Auricle. External Auditory Canal, 887 



The Tympanic Membrane, 888 



The Auditory Ossicles and Their Muscles 890 



Eustachian Tube. Tympanic Cavity 894 



Sound-conduction in the Labyrinth, 896 



Structure of the Labyrinth and the Terminations of the Auditory Nerve, . . 897 

 Quality of Auditory Perceptions. Perception of the Pitch and Intensity 



of Tones, 899 



Perception of Timbre. Analysis of Vowels, . 903 



Function of the Labyrinth in the Act of Hearing, 907 



Simultaneous Action of Two Tones. Harmony. Beat. Discord. Differ- 

 ential Tones and Summation -tones, 908 



Auditory Perception. Fatigue of the Ear. Objective and Subjective 



Hearing. Associated Sensations. Auditory After-sensations. .. 910 



Comparative. Historical, 9 12 



THE OLFACTORY APPARATUS. 



Structure of the Olfactory Apparatus 913 



Sensation of Smell, . 9i4 



