TABLE OF CONTENTS xxi 



PAGE 



Third Section: Movements of the Eyes and Visual Perceptions . . . .549 



1. Action of the Eye Muscles 549 



A. Limits of the Eye Movements 551 



2. Significance of the Eye Movements for the Outward Projection of Vis- 

 ual Perceptions 552 



3. Binocular Vision . 555 



A. Correspondence of the Two Retinae 555 



B. Single Vision with Two Eyes 555 



C. Perception of Depth 556 



CHAPTER XXII. The Physiology of the Nerve Cell and of the Spinal Cord . . . 559 

 1. General Considerations Concerning the Finer Structure of the Nervous 



System 559 



2. The Structure of the Spinal Cord 562 



3. Kinds of Nerves 564 



A. Classification According to Function . . 564 



B. Special Properties of Different Kinds of Nerve Fibers .... 565 



C. Magendie's Doctrine 565 



4. Functions of the Nerve Cell 566 



A. The Nutritive Functions of Nerve Cells . 567 



B. Physiological Stimuli of Nerve Cells 569 



C. Mode of Reaction of Nerve Cells to Stimulation 570 



D. Dependence of the Nerve Cell upon the Blood Supply, and the Effects 



of Poisonous Substances . 572 



E. Morphological Changes in the Nerve Cell. Reproduction and Regener- 



ation .... 574 



5. Reflex Processes .; . .. '. . . 575 



A. Segmentation in the Central Nervous System . . -.. . . . 575 



B. General Features of Reflexes . . . .... ... -. . . 576 



C. Inhibition of Reflexes .. ."' : ;. . 577 



D. Augmentation of Reflexes ... V . . 579 



E. Reflex Responses to Different Stimuli . fc . . . ... . 580 



6. Automatic Excitation . . ;> . . . 580 



7. Tonus . , . . .581 



8. Central Functions of Peripheral Nerve Cells 582 



9. Centers in the Spinal Cord 585 



A. Control of Skeletal Muscles . 586 



B. Influence of the Spinal Cord on the Vegetative Functions . . . 587 

 10. Conducting Pathways in the Spinal Cord 588 



A. Electrical Stimulation of the Cord ........ 588 



B. Methods of Determining the Conducting Pathways in the Spinal Cord. 589 



C. Anatomical Data Concerning the Conducting Pathways of the Cord . 591 



D. Experimental and Clinical Observations on the Conducting Pathways 



in the Spinal Cord 595 



CHAPTER XXIII. Physiology of the Brain-stem 599 



1. General Survey . 599 



A. Method . -' ... 599 



B. Divisions of the Brain 601 



2. The Medulla Oblongata, or After-brain 602 



3. The Cerebellum . . 605 



