THE EXTERNAL EAR. 



45 



trunks, or pass straight through the membrana propria, so that 

 by this means all the three layers of lymphatics belonging to 

 the membrana tympani intercommunicate with each other and 

 with those distributed in the cutis of the external auditory 

 meatus. It is further to be remarked, that after brushing off the 

 epithelium of the mucous membrane, and treatment with nitrate 



Fig. 282. 



Fig. 282. Lymphatics with their saccular dilatations lying imme- 

 diately subjacent to the fibrous framework of the mucous membrane. 

 From a specimen prepared with solution of nitrate of silver. 



of silver, a system of serous canals comes into view, both upon 

 the immediately subjacent membranes and trabeculse, and upon 

 the depressions and tunnel-like passages lying between them, 

 as was first described by Recklinghausen in the diaphragm of 

 the Rabbit. (See vol. i., p. 304.) This is distributed over the 

 whole surface of the membrana tympani, but especially over 

 those parts where the membrane is covered with small -celled 



