the gall-bladder's most common pathologic state, produces pain. Distention of the intestine causes great pain, but sharp cutting or burning causes none. In the abdominal viscera, as in the superficial parts, nociceptors have presumably been developed by specific harmful influences and each nociceptor is open to stimulation only by a stimulus of the particular type that produced it. As a result of the excitation of nociceptors, with which pain is associated, the routine functions, such as peristalsis, secretion, and absorption are dispossessed from the control of their respective nervous mechanisms, just as they are inhibited by fear. This hypothesis explains the loss of weight, the lassitude, the indigestion, the constipation, and the many alterations in the functions of the various glands and organs of the digestive system in chronic appendicitis. It readily explains also the extraordinary improvement in the digestive functions and the general health which follows the removal of an appendix which is so slightly altered physically that only the clinical results could persuade one that this slight change could be an adequate cause for such far-reaching and important symptoms. This hypothesis explains certain gall-bladder phenomena likewise,-- indigestion, loss of weight, disturbed functions, etc.,--and it may supply the explanation of the disturbance caused by an active anal fissure, which is a potent noci-associator, and the consequent disproportionate relief after the trivial operation for its cure. Noci-association would well explain also the great functional disturbances of the viscera which immediately follow abdominal operations.