The most important degenerative lesions concomitant with diabetes mellitus are those of the vascular system. Not only do these vascular lesions give rise to clinically important diseases involving the retina of the eye, coronary arteries, kidneys, nervous system, and all elements of the peripheral vascular tree, but they remain the most common cause of death in diabetics.1 Because of the association of diabetes and arteriosclerosis, the observation that the vascular lesions are of secondary causal relationship has been widely accepted. Moschowitz, however, has compared the incidence of hyperplastic arteriosclerosis in the aorta and pulmonary and coronary arteries of diabetics and nondiabetics dying of carcinoma, peptic ulcer, and essential hypertension. There was no significant difference.2 Furthermore, he found that in older diabetics 36% of men and 17.5% of women had a simultaneous onset of both diabetes and arteriosclerosis or that the diabetes developed subsequent to arteriosclerotic involvement. Boas has