NERVES IN THE MEMBRANA TYMPANI OF MAN 107 



complex and lie at such varying levels that it is impossible to 

 give any delineation which would exactly represent what exists. 

 To do so would only result in inextricable confusion. So it has 

 been found advisable to draw only the most evident of these 

 windings. Inside the capsule in fixed preparations there appears 

 a clear space which is due to a retraction of the fine fibrils during 

 the process of fixation. The impression given by unfixed prepar- 

 ations is that the ending is lying in a clear semi-fluid substance 

 enclosed within the capsule; the clear space within the capsule 

 does not appear. The sheath of Henle blends with the capsule. 

 At the distal end a fine twig may pierce the capsule, divide and end 

 in the epithelium immediately above the ending (fig. 5). At times 

 a second, very fine varicose fibril can be seen to enter the capsule. 

 These endings are frequently to be found in man though I have 

 failed to find similar endings in the dog, cat or monkey, nor are 

 they described by any of the other writers. As is known modified 

 vater-pacinian corpuscles are widely distributed in the skin. 

 They have been chiefly described in the tela subcutanea of the 

 genital organs and in the conjunctiva. It is interesting to note 

 their presence in the latter where they lie immediately under the 

 epithelium, no papillae being present, since as will be referred to 

 later there is a close correspondence between the nerve distri- 

 bution in the cornea and membrana tympani. 



The subepithelial plexus, ausseres oberfliichliches Geflecht of 

 Deinike, consists of interlacing bundles of very fine varicose 

 fibrils lying directly under the deepest layer of the epidermis. 

 Man}^ of these fibrils end after a long course in the terminal part 

 of which they run in the deeper layer of the epidermis (fig. 6.) 

 There is thus formed an intra-epithelial plexus from which fibers 

 pass upward towards the surface and end between the cells as 

 fine points. These endings often appear as knobs, but it appears 

 to me that the knob-like processes are probably artifacts produced 

 by the dye at the terminal point, for in the best stained and sharply 

 defined preparations the fine points are chiefly seen, whereas in 

 the less satisfactory preparations the bulb-like point predominates. 

 It is no unusual thing to trace a fiber a long distance through the 

 subepidermal plexus and even through the intra-epithelial plexus, 



