DeWitt, Nerves in the (Esophagus. 393 



be counted, each giving off numerous non-medullated branches 

 with their divisions and telodendria ; the whole ending was esti- 

 mated to cover an area 1.4 mm. by 0.8 mm. As Gaskell (17), 

 Edgeworth (15) and Langley (32) agree that the number of 

 sensory fibers in the white rami is small, Huber believes that 

 " this may be compensated for by the repeated division of those 

 fibers and by the relatively large area covered by their 

 branches." Both the terminal branches after losing their medul- 

 lary sheaths and the collateral non-medullated branches given 

 off from the medullated fibers at some node of Ranvier are be- 

 set with varicosities of different forms and sizes. 



That the terminal and lateral arborizations surround the 

 epithelial cells, ending on or between the cells in small varicose 

 thickenings, sometimes on the surface cells and sometimes on 

 the deeper ones, may be seen in PI. XXVI, Fig. 7, taken from 

 a cross section of the oesophageal mucosa of a young cat. In 

 the greater part of the oesophagus, these terminal arborizations 

 seem to be quite evenly distributed and it has seemed to rne 

 probable that nearly all of the epithelial cells come in contact 

 with one or more of the terminal nerve fibers. In the upper 

 part of the oesophagus, however, near its junction with the 

 pharynx, there are, in addition to these uniformly distributed 

 telodendria, certain peculiar ball-like masses, consisting of the 

 telodendria of several nerve fibers, whose branches are very 

 short and sooiT become non-medullated. The non-medullated 

 fibers soon break up into long, slender, varicose end branches, 

 forming end-brushes which meet and intermingle with the end- 

 brushes of other nerve fibers, making a dense and compact mass 

 of terminal nerve fibers, which, on superficial examination, re- 

 sembles a special sensory end-organ. Closer study, however, 

 fails to reveal the presence of a connective tissue capsule and, 

 in cross sections, we find that the ending is in the epithelium 

 and does not differ from the end-arborizations in other parts of 

 the mucosa except for the fact that here they are more closely 

 crowded together, more richly branched and beset with larger 

 and more abundant varicosities. PI. XXVI, Fig. 6, represents 

 the surface view of one of tliese ^iii-oalls, w.iich I aave found 



