356 CHARLES BROOKOVER 



of figure 2. We may mention again the grouping of cells and 

 fibers such as might be found in the myenteric or submucous 

 intestinal sympathetic. The proximity of nerve and arteries 

 (here represented in broken lines) is noticeable everywhere 

 peripherally. A close study of figure 1 will show how general 

 this is beyond the lamina cribrosa. I have noted instances 

 where the fibers of the nerve trail over the surface of arteries 

 but the method is not one suited to determination of the fine 

 twigs of nerve endings. 



Some study has been made of such cells as were favorably 

 impregnated in the series to learn whatever is possible of their 

 structure and relations. Drawings of some characteristic shapes 

 are shown in figure 4. There are very few cells that appear of 

 the primitive bipolar type with broad gradually tapering end 

 (dendrite) on the opposite side of the nucleus from the axone. 

 Perhaps all that were encountered were drawn. Rarely is there 

 a bifurcation of the dendrite (fig. 4) but that is possibly on ac- 

 count of the short distance from the perikaryon that the impreg- 

 nation of dendrites extends. Attention was paid to the direc- 

 tion of the dendrite in the nerve rami but there are about as 

 many extending centrally as peripherally. The arrows in the 

 drawings point distally. Many of the cells appear to be mono- 

 polar, though if there were two processes the sections were cut 

 in such a plane (longitudinal to the nerve rami) that one would 

 think both would be displayed. In some instances it was not 

 certain whether we had to deal with a bipolar cell or an unipolar 

 cell with a pericellular net. The nuclei of sheath cells frequently 

 showed in the preparations, especially about the ganglion cells, 

 but rarely were much in evidence in the rami if these were of 

 small calibre. As well as could be judged, the fibers are non- 

 myelinated and it may be that many of them are devoid of the 

 primitive sheath, and this may be the reason why they are 

 impregnated more deeply than any other nerves in this region. 

 It may be remarked also, that the fibers seem rather coarse. 

 Oftentimes the cells appeared to be located at some little dis- 

 tance from the nerve ramus (fig. 4) and sometimes from exami- 

 nation of the adjacent sections this is seen to be really so. 



