THE MOVEMENTS OF THE STOMACH 77 



steadily upon its diminishing contents. This is not a 

 movement powerful enough to secure the emptying of the 

 stomach, but adapts it to be gripped effectively by the 

 muscles of the body wall. The transverse band is at the 

 same time strongly contracted and the antrum has a very 

 small volume. The pyloric sphincter is said to be closed, 

 but it is a familiar fact that bile from the duodenum may 

 be pressed backward into the stomach under the stress of 

 violent vomiting. Profuse salivation precedes and accom- 

 panies the act. Such a reflex has a manifest value when 

 it serves to remove from the stomach material which might 

 prove poisonous. It occurs, however, under many circum- 

 stances when it seems not to have any advantageous re- 

 sult. Its apparent uselessness in seasickness has already 

 been alluded to. It appears equally illogical when, in 

 pregnancy, it is excited by irritation of the pelvic nerves. 



