INNERVATION OF THE DIGESTIVE TUBE 175 



Dogiel ('95) also described the neurones in the myenteric and 

 the submucous plexuses in great detail. So successful was this 

 investigator with his own methylene blue method that the accu- 

 racy and detail of his figures has scarcely been equaled by the 

 work of later investigators. 



Among the more recent investigators, Miiller ('11) has given 

 us a more or less detailed description of the myenteric and the 

 submucous plexuses in various regions of the digestive tube. 

 His figures and microphotographs indicate a wide range of varia- 

 tion among the neurones in these plexuses. His studies show, 

 furthermore, that with some differences in detail the myenteric 

 and the submucous plexuses are similarly constructed throughout 

 the length of the digestive tube. 



In spite of our knowledge of the general morphology of the 

 sympathetic nervous system and the histological characters of its 

 component neurones, little is known concerning the physiological 

 relationships of the sympathetic neurones and the distribution 

 of their axones and dendrites, especially in the peripheral sympa- 

 thetic plexuses. The present paper is primarily an attempt to 

 point out some of the morphological relationships of the neurones 

 in the myenteric and the submucous plexuses to each other and 

 to the muscle, gland and epithelial cells of the organs innervated 

 by them; thus to advance our knowledge of the morphological 

 basis for the physiological activities of the sympathetic nervous 

 mechanism in the walls of the digestive tube. 



I desire to express my indebtedness to Prof. G. L. Houser for 

 suggestions during the progress of this investigation and for 

 reading the manuscript. I am also indebted to Prof. F. A. 

 Stromsten for suggestions in technique. » 



MATERIAL AND METHODS 



The present series of observations is ba§ed primarily on prep- 

 arations of the stomach and the small intestine of the cat and 

 the dog. Good preparations for the study of the myenteric and 

 the submucous plexuses are not easily obtained. The silver 

 reduction method of Cajal and tlje method of Bielschowsky, 

 both of which were employed more or less successfully for the 



