CONTENTS. xiii 



BOOK III. 



THE CENTRAL NERVOUS SYSTEM AND ITS INSTRUMENTS. 



CHAPTER I. 



SENSORY NERVES, pp. 481 489. 



CHAPTER II. 

 SIGHT, pp. 490 555. 



PAGE 



Sec. 1. Dioptric Mechanisms 491 



The Formation of the Image, p. 491. Accommodation, p. 493. 

 Movements of the Pupil, p. 500. Imperfections in the Dioptric 

 apparatus, p. 506. 



Sec. 2. Visual Sensations , 511 



The origin of Visual Impulses, p. 511. Simple Sensations, p. 519. 

 Colour Sensations, p. 524. 



Sec. 3. Visual Perceptions 535 



Modified Perceptions, p. 536. 



Sec. 4. Binocular Vision 541 



Corresponding or identical points, p. 541. Movements of the eye- 

 balls, p. 542. The Horopter, p. 547. 



Sec. 5. Visual Judgments . 549 



Sec. 6. The Protective Mechanisms of the Eye 554 



CHAPTER III. 

 HEARING, SMELL, AND TASTE, pp. 556571. 



Sec. 1. Hearing 556 



The acoustic apparatus, p. 557. Auditory Sensations, p. 559. 

 Auditory Judgments, p. 565. 



Sec. 2. Smell .567 



Sec. 3. Taste 570 



