682 PHYSIOLOGY OF DIGESTION AND SECRETION. 



other muscles. Moreover, the presence of mucin serves doubtless 

 as a kind of lubricator that insures a smooth passage along the 

 esophageal canal. Finally by dissolving dry and solid food it pro- 

 vides a necessary step in the process of stimulating the taste nerves, 

 and, as is described below, the activity of the taste sensations may 

 play an important part in the secretion of the gastric juice. 



