THE EXTERNAL EAR. 39 



spaces. The colouring of the cells under the influence of solu- 

 tion of nitrate of silver varies, some scarcely appearing to be 

 at all stained, whilst others are black and opaque, the latter 

 chiefly occurring in the smaller polygons. The nuclei are here, 

 as is common after treatment with nitrate of silver, invisible, 

 though a few scattered ones are sometimes perceptible, usually 

 occupying an excentric position. 



Fig. 280. 

 d 



Fig. 280. Epithelium of the mucous membrane of the membrana 

 tympani of Man. Silvered preparation. 



The fibrous framework or matrix of the mucous membrane 

 is subjacent to the just-described epithelium, and on the other 

 hand rests upon the membrana propria. The arrangement or 

 disposition of the fasciculi in the membrana tympani of Man is 

 subject to variation. Fig. 281 consequently only gives a repre- 

 sentation of the form of the framework as it is most frequently 

 met with in the posterior segment of the membrana tympani. 

 Between the manubrium and the tendinous ring the membrane 

 is composed of very fine fibres, forming more or less broad trabe- 

 culse of similar structure that run in various directions. The 

 membrane varies in thickness. It usually extends on the one 

 side as far as to the manubrium, with the mucous membrane 

 of which it is continuous, or it already terminates at some dis- 

 tance from it, and is then continued by means of several 

 trabecular processes over the radial fibres, which two last inter- 

 weave together. I have usually observed a few trabecula? of 

 the framework extend to the processus brevis. On the other 

 side, towards the tendinous ring, trabeculre pass from the cen- 



