HUNGER 247 



imperious control of human actions. As Sternberg has pointed 

 out, hunger may be sufficiently insistent to force the taking of 

 food which is so distasteful that it not only fails to rouse appetite 

 but may even produce nausea. The hungry being gulps his 

 food with a rush. The pleasures of appetite are not for him — he 

 wants quantity rather than quality, and he wants it at once. 



Hunger may be described as having a central core and certain 

 more or less variable accessories. The peculiar dull ache of 

 hungriness referred to the epigastrium is usually the organism's 

 first strong demand for food ; and when the initial order is not 

 obeyed, the sensation is likely to grow into a highly uncomfortable 

 pain or gnawing, less definitely localised as it becomes more 

 intense. This may be regarded as the essential feature of hunger. 

 Besides the dull ache, however, lassitude and drowsiness may 

 appear, or faintness, or violent headache, or irritability and rest- 

 lessness such that continuous effort in ordinary affairs becomes 

 increasingly difficult. That these states differ much with indivi- 

 duals — headache in one and faintness in another, for example — 

 indicates that they do not indicate the central fact of hunger, 

 but are more or less inconstant accompaniments. The ' feeling 

 of emptiness,' which has been mentioned as an important element 

 of the experience, is an inference rather than a distinct datum 

 of consciousness and can likewise be eliminated from further 

 consideration. The dull pressing sensation is left, therefore, as 

 the constant characteristic, the central fact to be examined in 

 detail " (Cannon). 



Cannon and his colleagues have definitely proved that the 

 sensation of hunger is caused by strong contractions of parts of 

 the alimentary canal. As we shall see later when dealing with 

 transport (Chap. XXVIII.), there are certain definite movements of 

 the alimentary canal designated as peristaltic, associated with the 

 forward transference of the contents of the canal. In the absence 

 of any content other than gaseous, the cavities of the stomach, 

 lower oesophagus and upper intestinal region, at least, are almost 

 obliterated. This wave of contraction precedes the sensation of 

 hunger and may be regarded as the cause of it. Carlson and his 

 students, who were fortunate in having a subject with a per- 

 manent gastric fistula, have confirmed Cannon's work and carried 

 it further. They have shown that the local contraction is a sign 

 of a general state. According to Carlson and Luckhardt the 

 blood of a fasting animal, if injected into the vein of a normal 

 animal, is capable of producing in the latter contraction of the 

 gastric muscles, an effect which does not occur when the blood 

 of a well-fed animal is injected. 



