SECT. 



234-] 



SCALA MEDIA TY.MI'ANI. 



597 



thin prolongation. In sections made more carefully, fi r .245. 

 the thicker portion is seen to lie on the teeth of 

 the first series, as shown in fig. 241, and the inner 

 end appears directed towards the axis of the cochlea; 

 but I will not answer for it, that the portion which is 

 thus bent upwards is the true layer of this membrane, 

 because, as I have said, it is so excessively difficult 

 to see it in situ. If my figure should be incomplete 

 in this respect, I should be inclined to believe that 

 the thicker part of the striated lamella came ex- 

 ternally into connexion with the lamina spiralis; 

 but this point must be decided by future observa- 

 tions. — The striated lamella appears to be connective 

 tissue. The thinner portion is marked with trans- 

 verse strire, and the thicker part is fibrous in a direc- 

 tion parallel to the long axis of the cochlea. One 

 surface of the thicker portion often exhibits slight 

 rib-like prominences, and at the rounded end there 

 is often an appearance of a canal, in which I once 

 thought I observed a blood-vessel. It is remarkable, 

 that I never found, at this border of the membrane, 

 any certain indication of an attachment to the other 

 parts, while in the other direction the thin border 

 always has the appearance of being torn away. — 

 In the layer of connective tissue over the striated lamella, I believe 

 that I have sometimes seen blood-vessels; but this layer may be 

 very readily confounded with the loose shreds of periosteum of the 

 scala vestibuli which have become turned over; and as these always 

 contain vessels, I am not able to give any definite judgment on 

 the point. 



The scala media, in its situation and form is sufficiently indi- 

 cated by fig. 241, and I will only add in this place, that it is 

 certainly not filled with cells, as Claudius believes, but contains 

 a liquid, and exhibits a distinct epithelium in some places. These 

 places are, 1 , the sulcus spiralis, from the apex of the teeth of the 

 first series, up to the commencement of the organ of Corti; here 

 there is a simple pavement-epithelium particularly conspicuous in 

 the bottom of the furrow ; 2, the zona pectinata, from the line of 

 ending of the Cortian fibres onwards. It is very possible, that 

 beyond these places, there are others which are covered with 

 epithelium, and in one case especially, I have seen such a covering 

 on the inner Cortian fibres, appearing to be a continuation of that 



The striated 



lamella of the 

 membrana Cor- 

 tii, seen on 

 transverse sec- 

 tion in the ear 

 of the ox. View- 

 ed by Nachet's 

 lens No. 3, and 

 eye-piece Xo.l. 

 a. the thicker 

 portion of the 

 membrane. 



