Morgagni, in discussing the reason why the diaphragm should be excited into sympathetic reaction by the presence of an irritant in the nose, pointed out a fact that had been forgotten or the significance of which had not been appreciated. The membrane of the nose concerned in smell is supplied by the first pair of cranial nerves, the so-called olfactory nerves. Between this olfactory nerve and the nerve which supplies the diaphragm, the phrenic nerve, which is a cervical and not a cranial nerve, that is to say, comes from the central nervous system through the spinal cord in the neck and not directly from the brain, the older anatomists declared there was no connection. Morgagni pointed out that the mucous membrane of the nose is partly supplied also from the fifth pair of cranial nerves. From the fifth nerve, small branches of connection with the cervical nerves, as low even as the intercostal nerves, had been traced by Meckel. This shows the possibility of a nervous reflex; that is, of a communication of nerve impulses without the necessity for the intervention of the central nervous system. This was the first direct tracing of distant reflex nervous action in human physiology. The problem of nervous reflexes was to remain obscure for more than a century later, until light was thrown upon it by the investigation of the French physiologist, Claude Bernard. Here, however, was {43} the pregnant suggestion of the explanation of the seeming mystery. In subsequent cases Morgagni looked for the confirmation of his theory in this matter and found it. He pointed out that there was a relationship between the abdominal viscera and the olfactory mucous membrane of the nose. In one of his cases an epileptic seizure was always accompanied by a sense of discomfort in the upper abdominal region and a fetid odor. This odor was entirely subjective; that is, though extremely annoying to the patient it could not be noticed by any one else, even though the patient was close at hand and exhaled his breath at the moment of the observation. This would seem to point to the fact that Morgagni suspected there were other connections between the special senses and important organs besides those which had been discovered by anatomists up to that time. As a matter of fact the so-called sympathetic nervous system does place all the organs of special sense in direct connection with the other important organs of the body. Morgagni's suspicions were to be confirmed by the discoveries made in this sympathetic system during the succeeding century.