DISTRIBUTION OF THE NERVES IN THE SALIVARY GLANDS. 437 



as the fibrils which emerge and join them from the columnar 

 epithelial cells. It is frequently observable that the last rami- 

 fications of the axis cylinder are continuous with these fibrils ; 

 and that the columnar cells thus represent the continuations of 

 the finer and the finest medullated nerves with the sub-epithelial 

 plexus is frequently capable of direct proof, as appears from an 

 examination of fig. 80. We may even succeed, though rarely 

 (fig. 82), in effecting the complete isolation of all parts, and in 

 thus showing the continuity of the medullated nerves with the 

 processes of the columnar cells. It may thus be rendered evident 

 that these fine processes are in direct continuity with the axis 

 cylinder, from which they do not in any respect differ. At the 

 same time it may be remarked that the axis cylinder of the 



Fig. 82. 



Fig. 82. From the Rabbit, exhibiting a medullated nerve, becoming 

 continuous with an axis cylinder which passes directly into the pro- 

 cess of a cylinder cell, and directly open* into the columnar cell. 

 Magnified 590 diameters. 



afferent nerves appears to be thicker than the fibrillar processes 

 of the columnar cells, which must consequently be regarded as 

 continuations of the fibrillse of the axis cylinder. After the 

 nerve has penetrated the membrana propria of the salivary tube, 

 the axis cylinder either immediately terminates, or does so after 

 it has first run for some distance upon the membrana propria ; in 



