The research, previously mentioned, on the rhythmic sounds produced by the digestive process, I was engaged in when Boldireff’s paper was published. That contractions of the alimentary canal on a gaseous content might explain the hunger pangs which I had noticed seemed probable at that time, especially in the light of Boldireff’s observations. Indeed, Boldireff[204] himself had considered hunger in relation to the activities he described, but solely with the idea that hunger might _provoke_ them; and since the activities dwindled in force and frequency as time passed, whereas, in his belief, they should have become more pronounced, he abandoned the notion of any relation between the phenomena. Did not Boldireff misinterpret his own observations? When he was considering whether hunger might cause the contractions, did he not overlook the possibility that the contractions might cause hunger? A number of experiences have led to the conviction that Boldireff did, indeed, fail to perceive part of the significance of his results. For example, I have noticed the disappearance of a hunger pang as gas was heard gurgling upward through the cardia. That the gas was rising rather than being forced downward was proved by its regurgitation immediately after the sound was heard. In all probability the pressure that forced the gas from the stomach was the cause of the preceding sensation of hunger. Again the sensation can be momentarily abolished a few seconds after swallowing a small accumulation of saliva or a teaspoonful of water. If the stomach is in strong contraction in hunger, this result can be accounted for, in accordance with the observations of Lieb and myself,[205] as due to the inhibition of the contraction by swallowing. Thus also could be explained the prompt vanishing of the ache soon after we begin to eat, for repeated swallowing results in continued inhibition.[*] Furthermore, Ducceschi’s discovery[206] that hydrochloric acid diminishes the tonus of the pyloric portion of the stomach may have its application here; the acid would be secreted as food is taken and would then cause relaxation of the very region which is most strongly contracted. *[Footnote: The absence of hunger in Busch’s patient while food was being eaten (see p. 239) can also be accounted for in this manner.] The Concomitance of Contractions and Hunger in Man