150 THE AUDITOR Y NERVE AND COCHLEA, BY W. WALDEYER. 



After the removal of the epithelium in the region of the 

 organ of Corti, the vestibular surface of the membrana basilaris 

 appears to be quite smooth, or presents only a feeble radial 

 striation. The vas spirale, with the fibrous bands of its 

 adventitia, glimmers, through the superjacent textures when 

 this part is seen from the tympanal surface. 



The vas spirale of Huschke (figs. 323 and 331), sometimes double, 

 is a small vein imbedded like one of the sinuses of the dura mater in the 

 homogeneous matrix of the membrana basilaris (fig. 331). It is con- 

 nected by means of branches regularly given off (fig. 323) with vessels 

 of the lamina spiralis ossea. More externally we meet, as Breschet 

 observed, and as I can testify in many instances, with another vessel, 

 situated at the root of the ligamentum spirale (fig. 322). 



From the points of contact of the bases of the external 

 pillars of Corti onwarus (see below), the basilar membrane 

 presents a distinct radial striation (zona pectinata of Todd 

 and Bowman, 54). The striae are the expression of a thin 

 cuticular lamella, which lies on the vestibular surface of the 

 homogeneous connective-tissue substratum of the membrane, 

 and belongs to the epithelium of the ductus cochlearis. This 

 is particularly well shown in vertical sections (fig. 331), when 

 three layers are distinctly visible. * First, the cuticular 

 layer (u), the striation of which I agree with Henle (2@) in 

 considering to depend on the presence of fine fibres ; then the 

 middle layer (6), the principal portion of the basilar mem- 

 brane, a relatively thick structureless membrane, which 

 passes uninterruptedly into the labium tympanicum of the 

 crista spiralis (fig. 321), and below this, upon the tympanal 

 surface, is a layer of extremely fine connective-tissue fibrils, 

 running for the most part spirally, with delicate fusiform cells 

 (fig. 334), which when seen in transverse section (as in fig. 331), 

 are of course spheroidal, like the sections of the fibres, and 

 give a granular punctated appearance to the mass. The 

 younger the animals the thinner is the middle homogeneous 

 layer, and the thicker the tympanal fibrous layer; this ex- 

 hibits a greater development also in the first turn of the 



* See also the statements of Deiters (13) and Lowenberg (39). 



