184 ALBERT KUNTZ 



tracts toward the epithelial cells. On approaching the basal part 

 of an epithelial cell the fiber breaks up into two or more branches 

 which continue along the surface of the cell, giving off short 

 branches along their course. These terminal branches may in 

 some instances be traced along the surface of an epithelial cell for 

 nearly half its length. Figure 3, B, illustrates the terminations 

 of sympathetic nerve-fibers on epithelial cells in the ileum of the 

 cat. In this instance the epithelial cells were but slightly stained. 



The fibers terminating on them could, therefore, be traced to 

 their distal extremities. Figure 3, C, illustrates similar sympa- 

 thetic fiber-terminations on epithelial cells located at the free end 

 of a gastric fold in the cardiac region of the stomach of the cat. 

 In this instance the epithelial cells were stained more intensely. 

 Consequently, the terminal portions of the fibers could be traced 

 but for a short distance on their surfaces. 



Whether the sympathetic nerve-fibers terminating on cells of 

 the digestive epithelium are axones or dendrites can not be deter- 

 mined by their microscopic appearance. The fact that they ter- 

 minate on epithelial cells, however, seems to warrant the conclu- 

 sion that they are receptive fibers. Furthermore, in view of the 

 preponderance in the ganglia of the submucous plexus of neurones 

 with long slender dendrites, it is highly probable that they are 

 the dendrites of these neurones. 



Dogiel ('96) was led to believe, by observations of his pupil, 

 Sakusseff, on the digestive tube of fishes, that sympathetic ner\'e- 

 fibers actually terminate on cells of the digestive epithelium. 

 The opinion, based on both anatomical and physiological consid- 

 erations, that sympathetic nerve-fibers terminate on epithelial 

 cells in the digestive tube has been repeatedly expressed by recent 

 investigators. As far as the writer is aware, however, termina- 

 tions of sympathetic nerve-fibers on cells of the digestive epithe- 

 lium in higher vertebrates have not previously been described. 



In both the myenteric and the submucous plexus, terminations 

 of sympathetic nerve-fibers on sympathetic neurones may occa- 

 sionally be observed. In methylene blue preparations such fiber- 

 terminations may be studied most satisfactorily on neurones 

 which are stained but lightly. Terminations of nerve-fibers on 



