176 ALBERT KUNTZ 



study of other parts of the sympathetic nervous system, failed 

 utterly in the hands of the writer when applied to the digestive 

 tube of the cat and the dog. After numerous unsuccessful 

 attempts at intra-vitam staining with methylene blue, prepara- 

 tions of the stomach and the small intestine of the cat were 

 obtained by the use of this method in which some of the neurones 

 in the myenteric plexus and many of the fiber-tracts involving 

 both the myenteric and the submucous plexuses were well stained 

 and could be studied quite satisfactorily. Methylene blue prep- 

 arations in which the cell-bodies of neurones in the submucous 

 plexus were well stained were not secured. 



The pyridine-silver method as employed by Ranson^ was 

 found very useful for the study of the neurones in both the 

 myenteric and the submucous plexuses. In sections of the 

 small intestine of the dog successfully prepared by this method, 

 sympathetic neurones and fibers are well stained and may be 

 satisfactorily studied. In these preparations, however, it is rarely 

 possible to trace sympathetic fibers to their terminations on 

 gland or epithelial cells. Even this method does not yield as 

 uniformly good results when applied to the sympathetic plexuses 

 in the walls of the digestive tube as when applied to other parts 

 of the sympathetic nervous system or to the cerebro-spinal 

 nervous system. 



OBSERVATIONS 



Myenteric plexus 



The ganglia of the myenteric plexus are somewhat irregular 

 flattened or less-shaped aggregates of neurones interposed be- 

 tween the longitudinal and the circular muscle-layers of the 

 digestive tube. These ganglia are variously connected with 

 each other by commissures of non-medullated fibers arranged 

 either in distinct bundles or in broad flattened bands. In 

 sections of the stomach or the small intestine taken in the plane 

 of the myenteric plexus, these commissures may be traced from 

 one ganglion into another. In many instances four or more 

 commissures may be traced in as many directions from a single 



lAmer. Jour. Anat., vol. 12. p. 69. 



