of these procedures. The turgescence theory, furthermore, does not explain the quick onset of hunger, or its intermittent and periodic character. That the cells are repeatedly swollen and contracted within periods a few seconds in duration is almost inconceivable. For these reasons, therefore, the theory that hunger results from turgescence of the gastric mucosa can reasonably be rejected.
Hunger the Result of Contractions
There remain to be considered, as a possible cause of hunger-pangs, contractions of the stomach and other parts of the alimentary canal. This suggestion is not new. Sixty-six years ago Weber declared his belief that "strong contraction of the muscle fibers of the wholly empty stomach, whereby its cavity disappears, makes a part of the sensation which we call hunger." Vierordt drew the same inference twentyfive years later (in 1871), and since then Ewald, Knapp, and Hertz have declared their adherence to this view. These writers have not brought forward any direct evidence for their conclusion, though Hertz has cited Boldireff's observations on fasting dogs as probably accounting for what he terms "the gastric constituent of the sensation."
The Empty Stomach, and Intestine Contract.—The argument commonly used against the gastric contraction theory is that the stomach is not energetically active when empty. Thus Schiff stated "the movements of the empty stomach are rare and much less energetic than during digestion." Luciani expressed his disbelief by asserting that gastric movements are much more active during gastric digestion than at other times, and cease almost entirely when the stomach has discharged its contents. And Valenti stated only year before last "we know very well that gastric movements are exaggerated while digestion is proceeding in the stomach, but when the organ is empty they are more rare and much less pronounced," and therefore they can not account for hunger.
Evidence opposed to these suppositions has been in existence for many years. In 1899, Bettmann called attention to the contracted condition of the stomach after several days' fast. In 1902, Wolff reported that after forty-eight hours without food the stomach of the cat may be so small as to look like a slightly enlarged duodenum. In a similar circumstance I have noticed the same extraordinary smallness of the organ, especially in the pyloric half. The anatomist His also recorded
- Weber, Wagner's "Handwörterbuch der Physiologie," 1846, III2., p. 580.
- Vierordt, "Grundriss der Physiologie," Tübingen, 1871, p. 433.
- Knapp, American Medicine, 1905, X., p. 358; Hertz, loc. cit., p. 37.
- Schiff, loc. cit., p. 33.
- Luciani, loc. cit., p. 542.
- Valenti, loc. cit., p. 95.
- Bettmann, Philadelphia Monthly Medical Journal, 1899, I., p. 133.
- Wolff, Dissertation, Giessen, 1902, p. 9.