DeWitt, Nerves in the (Esophagus. 391 



in and around the adventitia, and non-medullated sympathetic, 

 vaso-motor fibers, which form a plexus in the adventitia and 

 end on the non-striped muscle of the media. 



Non-medullated nerves, the neuraxes of neurones, the cell 

 bodies of which are found in the ganglia of the intermuscular 

 plexus of the oesophagus, pass through the nerve trunks of that 

 plexus, penetrate the circular muscular layer, help to form the 

 nerve trunks of Meissner's plexus and finally, leaving this plex- 

 us, break up into an intra-muscular plexus in the muscularis 

 mucosae, from which fine fibers are given off which end on the 

 muscle cells as on non-striped muscle in other parts of the body. 

 The general arrangement of this intra-muscular plexus and its 

 relation to the submucous plexus is shown in PI. XXVI, Fig. 3, 

 which represents, sketched under low magnification, a portion 

 of the muscularis mucosae with the submucosa over it. 



The large, medullated, sensory fibers, found in the nerve 

 trunks of both the intermuscular and the submucous plexus, 

 pass through the muscularis mucosae and form, with frequent 

 branching, a finer meshed plexus in the deeper parts of the mu- 

 cosa. From this plexus branches, still medullated, are given off, 

 which pass, repeatedly dividing at the nodes of Ranvier, toward 

 the epithelium. Under the epithelium, these nerve fibers lose 

 their medullary sheaths and form a fine meshed sub-epithelial 

 plexus, whose fibers extend for considerable distances under the 

 epithelium. Before losing their medullary sheaths, many of 

 the medullated fibers give off at the nodes of Ranvier non-med- 

 ullated fibers, which also pass up toward the epithelium and 

 assist in the formation of the sub-epithelial plexus. From this 

 plexus, as well as from non-medullated fibers which come up 

 directly from the mucosa and seem to take no part in the form- 

 ation of the plexus, fine, varicose nerves pass up into the epi- 

 thelium, wind between the epithelial cells, occasionally giving 

 off longer or shorter branches, which terminate in varicosities 

 of different forms and sizes ; the terminal fibers also finally end 

 in ball-like thickenings on or between the epithelial cells, either 

 near the surface or at a greater depth. 



A well stained preparation of the oesophageal mucosa, 



