and therefore would not afford criteria for the diagnosis. On the other hand, it is certainly true that there are many instances in which the electrocardiogram may give the only sign of rheumatic activity. This is more apt to be true at the end than at the beginning of an acute attack. I have seen patients in whom there were no joint symptoms and who had only electrocardiographic changes. I remember one such patient, who came into the clinic ambulatory, with fever and with electrocardiographic changes, and we did not quite know why. She then developed a pericardial rub, and the reason for the electrocardiographic changes became evident. She later developed some joint symptoms which led to a diagnosis of rheumatic fever. But that case I think is exceptional. Usually the electrocardiogram is a manifestation of the disease which is diagnosed on the basis of other findings. There are in general three types of pathological changes: (1) There is a general inflammatory reaction with edema, interstitial swelling, leukocytosis and fibrinous degeneration. (2) There is the specific type of pathological change known as the Aschoff body, which is found in the interstitial tissue surrounding the small muscle bundles and particularly in the interstitial tissue surrounding the smaller arteries. (3) And then there is an arteritis which is also a definite rheumatic manifestation and which occurs in the coronary arteries as well as in other arteries of the body. We are particularly concerned with the coronary arteries where it causes an intimal thickening and eventually a fibrosis of the vessel wall.