ALTHOUGH the vasa vasorum, the nutrient vessels in the wall of the human aorta, have been studied in some detail,¹ there has been disagreement concerning the presence or extent of vasa vasorum in the coronary arteries. As early as 1876 Köster² suggested that the intimal proliferation and medial hypertrophy of "arteriitis" was related to the presence of vasa vasorum in the media and intima. In 1938 Winternitz et al.³ injected India ink into the wall of cleared coronary arteries and demonstrated the "presence of rich vascular channels surrounding and penetrating sclerotic lesions." They suggested that "here, undoubtedly, was the source . . .