94 AVERS. [Vol. VI. 



a wedge-shaped portion in which one can distinguish a struc- 

 tureless mass inclosing an elongated portion that has the 

 appearance of a number of capillary vessels in cross-section. 

 Corti's membrane is related to the surrounding parts in such a 

 manner that its inner and middle zones rest upon Huschke's 

 elevation (promontory) ; it then applies itself to the epithelial 

 thickening external to this and spreads out over Corti's organ, 

 inserting finally on the upper process of the ligamentum spirale 

 of the outer cochlear wall. By this means a canal is pro- 

 duced between the basilar membrane and Corti's membrane, 

 and between this and Reissner's membrane another hereto- 

 fore unknown canal, so that with the two scalae there are four 

 canals. 



Henle (1866, 124): The cochlear canal is divided into two 

 chambers by a membrane stretched across the canal paral- 

 lel to the basilar membrane, from the labium vestibulare to 

 the outer cochlear wall. This membrane — the membrana tec- 

 toria (M. Cortii) — is very delicate, but notwithstanding its 

 thinness, firm and resistant and of a very peculiar brittleness 

 and elasticity. 



It is inserted on the outer wall between the insertion of the 

 membrana basilaris and the stria vascularis. Three zones are 

 distinguishable, the middle of which is composed of several 

 layers of fine, somewhat bent fibres. The inner is structureless 

 and perforated by many holes. The outer is composed of a 

 very fine network made up of elongated meshes. 



Middendorp (1868, 193) : Corti's membrane is a cell secre- 

 tion. It covers the crista sulcata from the inner angle of the 

 membranous cochlea quite to the free border ; from here it 

 stretches across to the roof of the pillars of Corti, and ends in 

 a narrow seam or line which is fastened to the first connecting 

 members : a membrane with blood-vessels is never present. It 

 is i/Ci thick. It is a firm, elastic membrane. 



Kolliker (1867, 167) : The inner and outer hair cells all bear 

 a brush of fine, stiff, short hairs, which are inserted on the top 

 of the cell in a more or less semicircular line. The membrana 

 tectoria was still considered to be a discrete structure having 

 no organic relation to the auditory hairs. 



Rosenberg (1868, 242) : The largest portion of the epithe- 

 lium of the lower wall of the developing cochlear canal is cov- 



