THE NATURE OF HUNGER 293 



the same function of leading to the intake of food, and they usually 

 appear together. Indeed the cooperation of hunger and appetite is 

 prohably the reason for their being so frequently confused. 



The Sensation of Hunger 



In the present paper we shall deal only with hunger. The sensa- 

 tion 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 pang or gnawing, less definitely localized 

 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 restlessness such that continuous effort in ordinary affairs becomes 

 increasingly difficult. That these states differ much with individuals 

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

 that they do not constitute the central fact of hunger, but are more or 

 less inconstant accompaniments, and need not for the present engage 

 our attention. The " feeling of emptiness," which has been mentioned 

 as an important element of the experience, 5 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. 



Hunger can evidently be regarded from the psychological point of 

 view, and discussed solely on the basis of introspection; or it can be 

 studied with reference to its antecedents and to the physiological con- 

 ditions which accompany it — a consideration which requires the use of 

 both objective methods and subjective observation. This psychophysi- 

 ological treatment of the subject will be deferred till the last. Certain 

 theories which have been advanced with regard to hunger and which 

 have been given more or less credit must first be examined. 



Two main theories have been advocated. The first is supported by 

 evidence that hunger is a general sensation, arising at no special region 

 of the body, but having a local reference. This theory has been more 

 widely credited by physiologists and psychologists than the other. The 

 other is supported by evidence that hunger has a local source and 

 therefore a local reference. In the course of our examination of these 

 views we shall have opportunity to consider some pertinent new 

 observations. 



' See Hertz, "The Sensibility of the Alimentary Canal," London, 1911, p. 38. 



