122 THE MEMBRANOUS LABYRINTH, BY PROF. RUDINGER. 



cular formation on the inner surface of the columnar epithelial 

 cells in the otolithic sac of the Frog, by means of which its 

 contact with the otoliths is prevented. I have observed this 

 means of fixation of the otoliths very beautifully in transverse 

 sections through the auditory organ of the Frog. Otoliths are 

 essentially composed of carbonate of lime ; according to Henle, 

 however, after treatment with acids, there is a residue which 

 is composed of organic substances (otolith cartilage). Leydig 



Fig. 316 



Fig. 316. Otoliths of different classes of animals. 1, From the 

 Goat ; 2, from the Herring ; 3, from the Angler Fish ; 4, from the 

 Mackerel ; 5, from Pterois volitans (after Breschet) ; 6, from the Pike ; 

 7, from Cyprinus carpio ; 8, from the Ray (after Leydig) ; 9, from 

 Scymnus lichia (after Leydig) ; 10, from the Grouse (after Leydig). 



has observed in the otolith of the Grouse, that, after treatment 

 with bichromate of potash, peculiar lines occur at the two 

 poles, which converge towards the centre (fig. 316, 10). It still 

 remains to be mentioned that in Man and Birds, even when 

 the vestibule is quite uninjured, otoliths may be observed in 

 considerable numbers in the membranous semicircular canals, 

 especially in the horizontal one, and according to Hyrtl in the 

 fluid of the cochlea. In these cases it is impossible to admit 



