476 DIGESTION 



increase in the hunger sensation, and as these contractions became more 

 marked, the hunger sensations became more intense. On the last day of 

 starvation a burning sensation referred to the epigastrium was added to 

 that of hunger. The appetite ran practically parallel with the sensa- 

 tion of hunger, and both of these sensations became perceptibly dimin- 

 ished on the fourth or last day of starvation, this diminution being, 

 however, most marked in the sensation of appetite. Indeed, instead of an 

 eagerness for food, there developed on the last day a distinct repugnance 

 or indifference towards it. Accompanying these sensations of hunger 

 and appetite a distinct mental depression and a feeling of weakness were 

 experienced during the latter part of the starvation period. 



On partaking of food again the hunger and appetite sensations very 

 rapidly disappeared, and also practically all of the mental depression 

 and a great part of the feeling of weakness. Complete recovery from 

 the latter, however, did not take place until the second or third day 

 after breaking the fast. From this time on both men felt unusually 

 well; indeed they state that their sense of well-being and clearness of 

 mind and their sense of good health and vigor were as greatly improved 

 as they would have been by a month's vacation in the mountains. They 

 further point out that, since others who have starved for longer periods 

 of time unanimously attest the fact that, after the first few days, the 

 sensations of hunger become less pronounced and finally almost dis- 

 appear, they must have experienced the most distressing period during 

 their four days of starvation. Although the hunger sensation was 

 strong enough to cause some discomfort, it could by no means be called 

 marked pain or suffering, and was at no time of sufficient intensity to 

 interfere seriously with work. Mere starvation can not therefore be 

 designated as acute suffering. It is of further interest to note that dur- 

 ing the starvation period a continuous flow of secretion of acid gastric 

 juice was found to occur in the stomach, the presence of this acid prob- 

 ably explaining the acid or burning sensation experienced in the epigas- 

 trium on the last days. 



CONTROL OF THE HUNGER MECHANISM 



The control of the hunger mechanism, like that of any other mechan- 

 ism in the animal body, may be effected through the nervous system or 

 it may depend on the presence of chemical substances or hormones in 

 the blood. As a matter of fact, it can readily be shown that both those 

 methods of control are operative, and we will now consider briefly some 

 of the facts upon which this conclusion depends. 



Although many facts are now known with regard to the nervous con- 



