210 A MANUAL OF VETERINARY PHYSIOLOGY 



material lies in the stomach owing to paralysis of the organ, and 

 is never absorbed. 



The nervous mechanism of the stomach of ruminants is derived 

 mainly from the vagus, excepting for the third compartment, 

 which has a separate and, at present, unknown source of supply. 

 Stimulation of the vagus was found by Ellenberger to produce 

 energetic contraction of the reticulum, slow kneading movements 

 of the rumen, and slower and later-appearing peristaltic contrac- 

 tions of the abomasum, but no contraction of the omasum. 

 Section of both vagi was found to paralyse the oesophagus, 

 rumen, and reticulum, followed by tympany of the rumen. 

 Ellenberger could not obtain any effect on the stomach move- 

 ments by stimulating the sympathetics. 



The influence of the mind over stomach digestion is well known 

 in man, and we have already noted its effect in the experimental 

 feeding of the horse related at p. 180. Pawlow's fistula has 

 enabled this point in the lower animals to be settled with accuracy. 

 One of his dogs, while actively secreting gastric juice under the 

 influence of a ' sham meal,' was made angry and excited by being 

 restrained from chasing a cat ; the gastric glands at once ceased 

 secreting. Similarly by means of X rays the movements of the 

 cat's stomach have been observed to cease when the animal 

 became angry and excited. 



