394 Journal of Comparative Neurology. 



only in the pharyngo-cesophageal region, but which I have 

 found there in considerable numbers. Two large medullated 

 nerves are seen, which divide repeatedly into short medullated 

 branches, these breaking up almost at once into terminal end- 

 brushes, whose extremities meet and intermingle with those 

 from the fiber at the opposite extremity of the mass of teloden- 

 dria. Fig. 8 represents a cross section of a similar mass of 

 endings, showing the fine sub-epithelial plexus and the rich 

 branching of the terminal varicose fibers in the epithelium. 



The nerves ending in the mucosa of the frog's oesophagus 

 have been stained in gold chloride by Goniaew (i8), working 

 under Arnstein's direction, and in chrome silver by Smirnow 

 (41). Both describe the formation of plexuses of medullated 

 fibers in the deeper parts of the mucosa and of non-meduUated 

 fibers just under the epithelium, from which varicose fibers were 

 traced into the epithelium. The nerve fibers in the epithelium, 

 according to Smirnow, run either straight or in a more or less 

 winding course, between the epithelial cells, divide several 

 times, and, as fine, varicose fibers, surround the ciliated, as well 

 as the goblet cells which line the oesophageal mucosa of the 

 frog, ending free on both kinds of cells, either in points or in 

 knob-like thickenings. The goblet cells have an especially rich 

 nerve supply and are here regarded as unicellular glands. 



Malischeff (34) has recently investigated the nerve endings 

 in the oesophagus of the bird, but I have not had access to his 

 report of the results of his investigations. 



Retzius (36), with the chrome silver method, demonstrated 

 nerves entering the epithelium of the oesophageal mucosa of 

 the cat. These nerves branched freely in the epithelium and 

 ended between the epithelial cells. He says, however, that the 

 nerves in the oesophageal mucosa are by no means so numerous 

 as in that of the pharynx and larynx and end much nearer the 

 basement membrane. While some of the terminal fibers in 

 my preparations end on the deeper cells of the epithelial layer, 

 many may be traced, as seen in PI. XXVI, Fig. 7, to the flat- 

 tened cells near the surface, on which they may be seen to end. 



In summarizing the results of my investigations, it may be 



