CONTENTS. xiii 



PAGE 



827. The constituent cells ; cylinder or hair cells, rod or spindle cells . 1346 



828. The structure of the macula acusticse 1348 



829. The otoconia and otoliths .... ... 1348 



The Cochlea. 



830. The Canalis Cochlearis, its several parts . . ... 1349 



831. The basilar membrane 1350 



832. The organ of Corti 1352 



833. The rods of Corti 1354 



834. The inner hair cells 1355 



835. The outer hair cells 1356 



836. The endings of the cochlear nerve . 1357 



837. The tectorial membrane 1359 



838. The differences of the organ of Corti in different parts of the spiral 1359 



839. Measurements of some parts of the cochlea 1360 



SECTION III. 

 ON AUDITORY SENSATIONS. 



840. Noises and Musical Sounds 1361 



841. The characters of musical sounds ; loudness, pitch and quality ; 



fundamental and partial tones 1361 



842. The limits of auditory sensations 1363 



843. Appreciation of differences of pitch ....... 1364 



844. The number of vibrations needed to excite a sensation . . . 1364 



845. The characters of noises 1365 



846. The effects of exhaustion 1366 



847. The fusion of auditory sensations 1367 



848. The interference of vibrations. Beats 1367 



SECTION IV. 

 ON THE DEVELOPMENT OF AUDITORY IMPULSES. 



849. The transmission of impulses through the labyrinth ; the functions 



of the hairs and otoliths ........ 1370 



850. The analysis of complex waves of sound ; theories as to the mode 



of action of the organ of Corti 1372 



851. The appreciation of the nature of sounds ultimately a psychical 



process 1375 



852. Probable functions of the vestibular labyrinth 1376 



