It is interesting to note that comparative {45} pathology--that is, the study of the diseases of animals as illustrating corresponding conditions in human beings--had already attracted the attention of the Bolognese school of medicine. Albertini, who had been a professor of Morgagni's, pointed out that aneurisms are rarely found in animals, because brutes were not subject to emotions as are human beings. Morgagni made still further observations in this line to confirm his own conclusions in the matter. For a time in his earlier life he devoted himself to the study of fishes, because they seemed to promise to throw light on certain problems in human anatomy and pathology. How closely he studied pathological changes in tissues can be gathered from the fact that his observations led him to point out that aneurism of the aorta occurs most frequently at that part of the curvature of the aorta against which blood is constantly projected by the heart. The realization of the importance of this mechanical factor in the production of aneurism is one of the first successful results of carefully applied observation and knowledge of physical laws in the causation of changes in the tissues as opposed to elaborate theories with very little foundation in fact. Variations in the pulse attracted his attention, and he was among the first to point out that the occurrence of flatulency is liable to cause disturbance of the heart's action and to bring on noticeable cardiac palpitation in the absence of any organic affection of the heart itself. Morgagni also pointed out that intermittence of the pulse may be due to nervous conditions. He showed that severe mental shock or trying emotions may cause irregularity of the heart's action and pulse intermittency. Some of his observations in this matter show an intuition with regard to the nerve supply of the heart that is quite beyond the anatomy of his time, and seems to indicate that he suspected the existence and {46} function of the sympathetic system and also the existence of a special nerve supply to the small arteries. Perhaps Morgagni's most penetrating evidence of insight in pathology and its relations to clinical medicine is with regard to tuberculosis. Over a century and a half ago he insisted on its contagiousness. He refused to make autopsies on patients who had died of tuberculosis, and his position in the matter was undoubtedly of the greatest service in directing the attention of his contemporaries, and especially those closely in contact with him, to the important question of intimate association with tuberculous patients as a potent factor in the acquirement of the disease, more potent even than heredity which then occupied all men's minds on this subject.