292 



THE ALIMENTARY TRACT, ETC/ 



Fig. 192. 



A 



Klein describes a second system of ganglion-cells, situated in 

 meshes, which are formed by the nerve-trunks of the plexus itself. 

 These ganglion-cells are much larger than the former, and are 

 multipolar; their protoplasm, which is distinctly fibrillar, with 

 granules between the fibrils, is provided with one or two long, thick 

 processes and several short and thin ones ; generally the processes 

 are branched. The general shape of the cells is oblong, the thick, 

 long processes being commonly at the two opposite poles. The 

 cells are generally isolated, sometimes situated in the centre of a 

 mesh, or more commonly near a nerve-trunk that borders the mesh 



on one side. Each ganglion-cell 

 is connected with a nerve-trunk 

 of the plexus by at least one 

 process. In a few of the nerve- 

 trunks of the general plexus, iso- 

 lated medullated nerve-fibrils are 

 seen to pursue an almost straight 

 course from one trunk into 

 another and divide into two. 

 There is no connection between 

 these medullated fibres and the 

 ganglion-cells. 



Auerbach's plexus is a much 

 finer plexus than that just de- 

 scribed, and the ganglia are much 

 smaller. It supplies twigs to 

 the Muscularis nnicosa; these break 

 up into fine fibrils, which follow 

 the direction of the muscle-fibres ; 

 other twigs supply the blood- 

 vessels, with which they can be 

 traced into the bases of the folds 

 of mucous membrane. Thanhoffer 

 has recently (/. ^.) described nerve- 

 fibrils, which terminate in the 

 mucous epithelium.] 



D. The Large Intestine (Fig. 



From a transverse section of the large intestine 

 of Rana temfioraria, moderately distended. 

 G. H. 



A Denser portion of submucous coat. 



B Looser portion of submucous coat. 



U Artery, cut obliquely. 



/> Circular muscle-layer. 



E Longitudinal muscle-layer. 



a. General description. The large intestine is a flask-shaped 

 viscus, lying in the median line. The small intestine opens into it 



