50 THE EXTERNAL AND MIDDLE EAR, BY J. KESSEL. 



over the cell margins, as well as over the nuclei, to reach 

 adjoining or more distant cell- layers. I am unable to make 

 any positive statement as to their mode of termination. 



Before passing to the consideration of the middle layers of 

 the membrana propria, it may here be mentioned that nume- 

 rous nerve fibres proceeding from the basal plexus penetrate 

 between the fibres of the membrana tympani, and either 

 pursuing a tortuous course, or undergoing continual dichoto- 

 mous division, apply themselves to the tendinous fibres, or 

 traversing the spaces and lacunae between these, are distri- 

 buted as nerves of the mucous membrane. In these territories 

 of distribution nucleated nodal enlargements similar to those 

 above described also occur. 



Thus we have found in the membrana propria certain fissures 

 and vascular openings, with their just-mentioned contents, 

 and in addition a large number of nucleated enlargements 

 provided with two or more processes which are connected 

 with the nerves there distributed, and are placed over and 

 between the several layers of fibres. I once more adduce 

 these facts, because up to the present time all cellular ele- 

 ments found between the fibres of the membrana propria 

 have been considered to be connective tissue, whilst in truth, 

 as the above description shows, only a small number of them 

 belong to that tissue, and the greater part must be regarded 

 as belonging to the blood and lymphatic, or to the nervous 

 system. 



Lastly, in regard to the nerves of the mucous membrane 

 of the membrana tympani, I must first observe that they are 

 by no means so sparingly distributed to it as has been hitherto 

 maintained. Here also we find a vascular plexus and a sub- 

 epithelial plexus. The former accompanying the lymphatics 

 earlier than the bloodvessels, obtains its fibres partly from the 

 plexus tympanicus, by means of twigs which pass to the mem- 

 brana tympani at various points of the periphery together 

 with the mucous membrane of the tympanic cavity, and partly 

 from those nerves which lie in the cutis, by means of fibres 

 that perforate the membrana propria. It distributes its 

 branches on the one hand to the capillary bloodvessels and 

 lymphatics, and on the other hand to the subepithelial plexus. 



