I. CHARACTER OF TISSUE CHANGES ASSOCIATED WITH ACTIVITY OF THE RHEUMATIC PROCESS
In 1904 Aschoff1 emphasized the association of the myocardial nodule with rheumatic fever. This marked the first recognition of histologic changes specific for rheumatic disease. During recent years the conception of the anatomic distribution of rheumatic lesions has been explained largely through the careful histologic studies of the pathologists. Vascular structures other than the cardiac muscle and valves have been found to be involved by the rheumatic process. Lesions specific in their histologic appearance have been described in the aorta by Klotz,2 in the auricles by MacCallum,3 in the blood vessels, aorta and auricles by Pappenheimer and VonGlahn4 and in many other organs by Graff,5 Paul6 and Shaw.7 That these lesions are extremely widespread in rheumatic fever has been demonstrated by the recent observations of Klinge,8 who in detailed histologic