88 THE MEMBRANOUS LABYRINTH, BY PROF. RUDINGER. 



the attached surface. In specimens that have been hardened 

 in chromic acid or in chromate of ammonia, these nuclei some- 

 times form regular rows, so as to present many of the charac- 

 teristic appearances of a pavement epithelium. After repeated 

 observations recently made on carefully prepared specimens, I am 

 inclined to think that, as Henle and Hasse have already stated, 

 there is really no epithelium here, but that the appearances 

 presented are simply due to the numerous nuclei of the perios- 

 teum. Henle finds the periosteum of the labyrinth analogous 

 to the sub-arachnoideal tissue, the pigment cells, however, being 

 very few in number. The calcareous particles described by 

 Kolliker and Henle as existing in the periosteum are absent in 

 some cases, whilst in others they are very numerous. 



If an attempt be made with the aid of a chisel to dissect out 

 the labyrinth, it will soon be discovered that not only the two 

 sacculi in the vestibule, but also the membranous semicircular 

 canals, are at certain points closely connected with the perios- 

 teum. A clear view of the histological relations of the osseous 

 and of the membranous labyrinths respectively, can therefore 

 only be obtained by making transverse sections through the 

 temporal bone decalcified in chromic acid. 



In reference to the sacculi it may be observed that the 

 utriculus is more closely attached to the bones of the median 

 wall of the vestibule, than the sacculus rotundus. This, as Ode- 

 nius has already pointed out, is separated from the recessus 

 hemisphericus by a moderately thick and loose layer of con- 

 nective tissue, which surrounds the nerve fibres and vessels 

 traversing it. The two sacculi occupy about two-thirds of 

 the cavity of the vestibule. The utriculus extends farther 

 laterally than the sacculus rotundus, but neither of the two 

 touches the lateral wall of the vestibule or footplate of the 

 stapes ; topographical relations that I had already described 

 in 1866 * 



The membranous semicircular canals are attached to the 

 periosteum on the convex side of the osseous canals by mode- 

 rately broad bands of connective tissue, which I call the liga- 

 menta labyrinthi canaliculorum et sacculorum. At the points 



* Aerztliches Intelligenzblatt, Juni. 



