84 AVERS. [Vol. VI. 



development of the remainder, than by massing together the 

 whole large number of cells into a compact plate as in a macula 

 or a papilla, as occurs in most of the sense organs of the ear. I 

 conceive the cause which lies behind the remarkable growth of 

 the cochlea in length and spiral course to be the physical neces- 

 sity for the isolation of the cells and the greater perfection, the 

 increased delicacy and sensitiveness for perception of the hairs 

 borne by the cells. 



THE HAIR BAND (mEMBRANA CORTI, MEMBRANA TECTORIA). 



1. Historical. 



2. Form and Relations of the Band to the Cochlea. 



3. Sensory Hairs. 



a. Disposition in the band. Relation to the sensory cell. 

 d. origin. 



c. number. 



d. course. 



e. normal relation to scala media. 



/. size at base and tip and relative lengths of hairs in different 



parts of the organ of Corti. 

 g. intercapillary substance. 

 h. comparative. 



4. Loewenberg's Net. 



a. posidon and extent. 

 d. size of net and meshes. 



c. origin and attachments. 



d. varieties and variations in same cochlea. 



e. composition of the cords of the meshes. 



All students of the anatomy of the vertebrate ear down to 

 the time of Ecker and Reich had failed to find in the chambers 

 of the ear cellular structures of a specific kind, and almost all 

 of them considered the ear to be more or less completely filled 

 with a gelatinous matter which was specially well marked in the 

 ampullae and over the maculae, — in connection with the jelly 

 otoliths were frequently found. F. E. Schultze in 1858 first 

 described the ampullary gelatine as a crest of long, straight, 

 auditory hairs, as he called them. It is true Eckei", and later 

 his student Reich, had found the ciliate epithelium of the 

 Petromyzon ear, but they did not discover the true auditory 



