CONTENTS. xiii 



PAGE 



827. The Constituent Cells ; Cylinder or Hair Cells, Rod or Spindle Cells 208 



828. The Structure of the Maculae Acusticse 210 



829. The Otoconia and Otoliths 210 



The Cochlea. 



830. The Caualis Cochlearis, its several parts 211 



831. The Basjlar Membrane 212 



832. The Organ of Corti 214 



833. The Rods of Corti 216 



834. The inner Hair Cells 217 



835. The outer Hair Cells 218 



836. The Endings of the Cochlear Nerve 219 



837. The Tectorial Membrane 221 



838. The Differences of the Organ of Corti in Different Parts of the Spiral 221 



839. Measurements of some Parts of the Cochlea 222 



SECTION III. 



ON AUDITORY SENSATIONS. 



840. Noises and Musical Sounds 223 



841. The Characters of Musical Sounds ; Loudness, Pitch, and Quality; 



Fundamental and Partial Tones 223 



842. The Limits of Auditory Sensations 225 



843. Appreciation of Differences of Pitcli 226 



844. The Number of Vibrations needed to excite a Sensation . . . 226 



845. The Characters of Noises 227 



846. The Effects of Exhaustion 228 



847. The Fusion of Auditory Sensations 229 



848. The Interference of Vibrations. Beats 229 



SECTION IV. 

 ON THE DEVELOPMENT OF AUDITOKY IMPULSES. 



849. The Transmission of Impulses through the Labyrinth ; the Func- 

 tions of the Hairs and Otoliths 232 



850. The Analysis of Complex Waves of Sound ; Theories as to the Mode 



of Action of the Organ of Corti 234 



851. The Appreciation of the Nature of Sounds ultimately a Psychical 



Process 237 



| 852. Probable Functions of the Vestibular Labyrinth 238 



