194 HUMAN PHYSIOLOGY 



from the prevailing average. Inhibition is seen more 

 commonly than augmentation. 



It is most interesting to discover that the tonic con- 

 traction of the fundus and the peristalsis of the antrum 

 both may be interfered with as a result of psychic 

 factors. These movements have often been studied 

 by means of the X-rays. (This is accomplished by 

 mixing a substance with the food which will intercept 

 the rays and so image the contents of the stomach as 

 a silhouette on a suitable screen.) It has been proved 

 by repeated observations that the stomach of an angry 

 or frightened animal ceases to work and remains in a re- 

 laxed condition until the animal is pacified. The hygienic 

 suggestion is obvious. It will be emphasized later. 



Hunger. When a person has been for some time 

 without food well-marked pangs may be experienced. 

 These are referred to the stomach or to the lower end 

 of the esophagus and they come and go at intervals. 

 These gnawings may be considered to be sensations of 

 hunger as distinguished from appetite. Appetite is 

 a matter of association, involving memories and antici- 

 pations; hunger is a simple physical symptom piercing 

 to consciousness and known to infants and to the lower 

 animals as well as to adults. Ingenious experiments 

 have shown that the pangs of hunger are associated 

 with strong contractions of the fundus of the stomach. 

 This may well account for the fact that these sensations 

 are often accompanied by sounds due to the shifting 

 about of gas in the empty organ. 



It is probable that the hunger pangs are much more 

 marked in some individuals than in others. In the 

 course of a long fast they become weaker and may 

 cease altogether in two or three days. So it happens 

 that absolute fasting is described as not distressing 

 while insufficient feeding is certainly productive of 

 real suffering. The most harrowing stories of misery 

 endured by Arctic and other explorers have had reference 

 rather to short rations than to downright starvation. 



