148 Irving Hardesty 



various other elements of the organ of Corti. It is probable that some 

 of these attachments consist of crumpled bits of the distorted accessory 

 membrane, augmented by coagulum filaments. Also some of the de- 

 scriptions of various lines and markings on the under surface of the 

 tectorial membrane, noted above, may have been dealing with appear- 

 ances produced by the distorted accessory membrane as well as with 

 crumplings of the peripheral condensation of the main body. 



The processes by which the accessory tectorial membrane is developed 

 from the greater epithelial thickening have yet to be worked out. Evi- 

 dently it is one of the last structures formed, and probably its individual 

 character may be due to its being formed during a period of rapid 

 displacement of the parts. 



The Attachment of the Tectorial Membrane, 



All the observers invariably agree that the tectorial membrane is 

 attached along its inner thin zone upon the surface of the labium vesti- 

 bulare. This attachment is developed early in the development and is the 

 line of fixation instrumental in the final course and arrangement of the 

 fibers of the membrane resulting from, first the widening of the greater 

 epithelial thickening and then followed by its retrogression and decrease 

 in width. 



Numerous investigators claim other attachments, but there is lack 

 of agreement as to their location. There are to be found in the litera- 

 ture claims for attachment of the under surface of the membrane 

 varying from attachment to the epithelium of the spiral ligament 

 (Corti) and the cells of Claudius (Coyne and Cannieu), all the way 

 across the lamina to attachment upon the inner supporting cells of 

 the organ of Corti (Shambaugh). The majority of the claims are for 

 attachment to the structural elements comprising the organ of Corti 

 alone, especially to the hairs of either the inner or outer hair cells or 

 both. Of the more recent papers, Kishi, '07, agreeing with Bottcher, 

 '69, states that the membrane is connected with the lamina reticularis 

 and with the hairs of both the inner and outer series. Siebenmann, 'OT), 

 denies connection with the lamina reticularis in either the embryo or 

 the adult. Von Ebner, '02, holds the membrane was attached to the 

 lamina during development, but, in the adult, after the displacement of 

 the parts, this attachment is necessarily lost and the membrane extends 

 free over the spiral sulcus and organ of Corti. Eickenbacher, '01, 



