MEMBRANA PROPRIA OF THE DUCTUS COCHLEARIS. 141 



description of the periosteum of the labyrinth. I may, how- 

 ever, just mention the very frequent occurrence of stellate 

 pigment cells in it, closely resembling the stroma cells of the 

 choroid. They are very numerous both in Man and in the Rat. 

 The internal surface of the periosteum, with the exception of 

 the tympanic surface of the membrana basilaris, where, like 



Fig. 322. 



Fig. 322. Vertical section through the second turn of the cochlea 

 in Yesperugo noctula (the membrana tectoria inserted in accordance 

 with its position in another specimen), magnified 100 diameters, j^, 

 cochlear nerve, with a part of the ganglion spirale ; e e, cushion of con- 

 nective tissue more firmly connected with the periosteum than in 

 fig. 221 ; L Sp, ligamentum spirale of homogeneous character, with 

 a bloodvessel immediately external to it ; jR R lt Reissner's membrane, 

 indicated by a punctated line ; h, external portion or slope of the roof 

 (Abdachung), with the three external hair cells in situ. The internal 

 hair cells, as well as the epithelium of the sulcus spiralis internus, not 

 completely preserved. The rest of the lettering as in fig. 321. 



Kolliker (30), I have been unable to discover them, is covered 

 by a single layer of large flat nucleated cells, which, when 

 subjected to the action of nitrate of silver, presents the same 

 markings as are visible in lymph sacs or serous membranes. 

 Luschka (70) has already referred to this point, and his state- 



