SENSE OF HEARING STRUCTURE OF COCHLEA. 



783 



from which it derives its name. 1 In regard to the mode in which the ulti- 

 mate subdivisions of the Auditory nerve are distributed upon the lining 

 membrane of the labyrinth, the observations of Riidinger and others have 

 demonstrated that there are certain spots named cristre acustictie in the am- 

 pulla? and macula? acusticre in the sacculi, which are of a yellowish color. 

 The epithelium of these parts presents two forms of cells, of which one is 

 columnar and supporting, whilst the other is fusiform (Fig. 276), and seems 



FIG. 276. 



Diagram of the mode of termination of the auditory nerve in the ampulla and sacculi. 1, cartilage 

 of the wall of the ampulla; 2, structureless basement-membrane ; 3, doubly-contoured nerve-fibre; 

 4, axis-cylinder traversing the basement-membrane; 5, plexiform union of fine nerve-fibres with in- 

 terspersed nuclei; 6, fusiform cells, with nucleus and dark fibre in their interior; 7, supporting cells; 

 8, auditory hairs. 



to represent the terminal organs of the vestibular nerves. The fusiform 

 cells are each connected at their base with a branch of the auditory nerve, 

 and terminate in a long hair-like process. They contain a certain amount 

 of yellowish pigment. The structure of the cochlea has recently been ma- 

 terially elucidated by the extraordinarily minute and delicate dissections of 

 Corti, 2 Schultze, Kolliker, and others, and may readily be understood from 



1 For a more detailed sketch of the Comparative Anatomy of the Organ of Hear- 

 ing, see the- Author's Principles of Comparative Physiology, $$ 711-714. 



2 See his Memoir in Ko'liker and Siebold's Zeits. fur wiss. Zoologie, 1851, Bd. iii, 

 Heft 1 ; also Prof. Kolliker's Mikroskop. Anatomic, Bd. ii, $ 289, and his Manual of 

 Microscopic Anatomy, 1860; Fick, Anat. u Physiol. der Shines Organe, 1862, p. 

 122; Eiidinger, Das Gehor-organe, Munchen, 1867, with an Atlas of Photographs ; 

 Eeichei-t, Abhand. d. k. Akad. der wiss. zu Berlin ; C Hasse, On the Mode of Ter- 

 mination of the Acoustic Nerves in Birds, in the Gottingen Nachrichten, 1867, and 

 Kolliker's Zeits., Bd. xvii, p. 598; Pritchard, in Monthly Microscop. Journ., 1873, 



