viii PHYSIOLOGY 



3. Nerves and centres of phonation. 4. Mechanical conditions for the 

 production of laryngeal sounds ; function of different parts of the 

 phonatory system. 5. Principal characteristics of the singing voice. 

 6. Difficulties and natural imperfections of singing. 7. The vowel 

 system in phonetic language. 8. Theory of physical nature of vowel 

 tones. 9. System of semivowels or sounding consonants, middle conso- 

 nants, and mute consonants. 10. Composition of syllables and words. 

 11. Writing, or graphic language. Bibliography. 



CHAPTER IV 



GENERAL PHYSIOLOGY OF THE NERVOUS SYSTEM . . .175 



1. Structural elements of the nervous system. Theory of inde- 

 pendent neurones, or continuity of neuro-fibrils. 2. Conditions, laws, 

 and phenomena of conduction in nerve. 3. Rate of conductivity : 

 diphasic character of the impulse arousing it. 4. Metabolism of nerve : 

 electromotive phenomena during rest and excitation ; demarcation 

 current, action current. 5.- Excitation of nerve. Natural stimuli and 

 artificial (chemical, mechanical, electrical) stimuli. 6. Factors in life 

 and death of nerve : conditions of excitability. 7. Polar effects of 

 constant current (electrotonus) : correlative changes in excitability and 

 conductivity. 8. Excitatory action of electrical currents. Laws of 

 excitation. 9. Theories as to origin of neural activity. 10. General 

 functions of nerve-centres. Ganglion cells and central fibrillary net- 

 work. Bibliography. . 



CHAPTER V 



SPINAL CORD AND NERVES. . . . . .278 



1. Grey and white matter of the spinal cord. 2. Extra- and intra- 

 spinal nerve-cells ; their connections with the root-fibres and tracts 

 which make up the spinal columns. 3. Spinal roots. Bell-Magendie 

 law of localisation of sensory and motor tracts. Waller's law of 

 degeneration after section. 4. Functional relations between afferent 

 and efferent roots. 5. Segmental arrangement of spinal roots. 6. 

 Reflex activity of segments of cord ; shock after section of cord. 7. 

 Short and long spinal reflexes ; laws of reflex spread. 8. Genesis of 

 spinal reflexes ; central factors that inhibit or promote them. 9. Tonic 

 and automatic functions of spinal cord ; "knee-jerk " or patellar reflex. 

 10. Trophic functions of spinal cord. 11. Sensory functions and 

 Pfliiger's "spinal soul." 12. Spinal cord an instrument of the brain ; 

 spino-cerebral and cerebro-spinal paths of conduction. 13. Localisation 

 of principal spinal centres ; phenomena of spinal deficiency (dogs with 

 amputated cord, Goltz). Bibliography. 



