JOURNAL OF MICROSCOPICAL SCIENCE. 



EXPLANATION OF PLATE XXVIII, 



Illustrating Dr. Pritchard's paper " On the Termination of 

 the Nerves in the Vestibule and Semicircular Canals 

 of Mammals.'^ 



Portions of a transverse section through the macula acustica of saccule 

 of cat, ten months old. x 750 dia. 



A. Centre of macula. Otolith mass above, into which the long cilia are 

 projecting ; the otoliths themselves having been dissolved out. Nerve-epi- 

 thelium, lying on the modified periosteum, consists of thorn-cells and 

 atrophied bristle-cells kept in position by the membrana reticularis. 



B. Intermediate portion. Otolith mass as before, cilia not so long. 

 Thorn-cells as before; bristle-cells perfect towards the outer side, atro- 

 phying towards the inner. Nerve-epithelium has been separated by 

 accident from tissue beneath, whence nerve-filaments are seen passing 

 upwards. 



C. Edge of macula. Otolith mass thinning oif towards the columnar 

 epithelium, cilia short and stumpy. Membrana reticularis becoming 

 gradually lost. The nerve-epithelium changing by degrees into ordinary 

 columnar cells. 



