I09& THE SENSES 



balloon, the man experienced a typical hunger pain. During his 

 own five days' fast Carlson recorded these contractions by means 

 of a small balloon attached to a rubber tube, which was swallowed 

 and allowed to remain in the stomach. The tube was connected 

 to a recording apparatus. It was found possible to go to sleep 

 with the balloon in the stomach, and to obtain a record all through 



ii. .!:. 



j ; I I S f, I) H I I 



III I 



Fig. 473. Gastric Hunger Contractions in a Man at a More Advanced and Intense 

 Stage than in Fig. 472. Tightening of the belt at x did not stop the con- 

 tractions which ran the usual course to their termination. To be read from 

 left to right (Carlson and Lewis). 



the night. After the first day of starvation the hunger sensation 

 referred to the epigastrium was almost continuous, and did not 

 wholly disappear during the intervals between the periods of 

 vigorous gastric contractions. This feeble continuous hunger sen- 

 sation was obviously associated with the increased tonus and the 

 more or less continuous, although weak, rhythmical contractions 

 that correspond to the periods of relative quiescence of the empty 

 stomach during prolonged starvation. The precise manner in which 

 the hunger contractions of the stomach arouse the pangs or pains 

 of hunger remains in doubt. Since the sensation has a specific 

 character, it is to be supposed that it is subserved by a special 

 sensory apparatus with receptors in the stomach. The vagi do not 

 seem to be concerned. But the gastric contractions during digestion of 

 a meal notoriously do not cause such sensations, and therefore it has 

 been suggested that the nervous mechanism associated with the 

 local sensation of hunger becomes more and more excitable in the 

 absence of food, until at last the threshold is reached at which the 

 stimulus connected with the hunger contractions becomes effective. 

 It comes to the same thing to say that the presence of food in some 

 way inhibits the discharge which leads to the sensation. This, 



