440 C. W. PRENTISS 



straight and of the same diameter throughout, the chambers in 

 the membrana taper as we go from the epitheUum and curve 

 toward the inner angle of the cochlear duct and are probably 

 irregular in length and arrangement. My conception of the 

 structure of the membrana based upon the preparations already 

 described is shown diagrammatically in figure 8. The reticular 

 structure is shown at the bases of the chambers, the thickenings 

 at the angles of the meshes extend lengthwise of these chambers 

 and when seen in side view, as in axial sections, they give the 

 membrane the fibrous or striated appearance which has been so 

 frequently described. This appearance was rightly interpreted 

 by Coyne et Cannieu ('95). In a vertical section usually more 

 than one layer of cuticular chambers may be seen and hence the 

 striations appear numerous, indistinct and close together. Few 

 investigators have made horizontal sections of the cochlea and 

 in the adult and in late fetal stages such sections are difficult 

 to obtain. Hardesty shows a section (fig. 9) in which at a cross 

 sections of the 'fibers' are seen, and he has drawn a reticulum 

 with thickenings at the angles. He states that the fibers seem 

 to anastomose and appear to be connected with each other by 

 fine collateral filaments but attributes this appearance to shrink- 

 age and coagulation. On pages 161 to 162 he states that ''The 

 membrana is not a lamellated structure. Ever since 1869 when 

 Bottcher teased portions of it and found them to contain fibers 

 the fibrous structure of the membrane has been conceded by all 

 who have studied it with reference to its structure. Sections in 

 different planes, as made by Coyne and Cannieu ('85) ['95] and 

 here (Fig. 9) indicate clearly its fibrous structure." ^ 



It is certain that Shambaugh did not concede its fibrous struc- 

 ture, as he states that it is lamellated. On page 132 Hardesty 

 states: "Lowenberg ('64) thought that the membrane consisted 

 of layers one above the other; Gottstein ('72) pictured it as 

 structureless, and many others after these have failed to compre- 

 hend its character." Rickenbacher does not figure any very 

 definite structure nor does he account for its development. As 



^ Italics mine. 



