Interest in the thebesian vessels or sinusoids has been renewed to a considerable degree in recent years. Pratt,1 Kretz2 and Wearn,3 particularly, have studied these vessels, and have expressed the belief that the heart can be effectively nourished through these channels after both coronary arteries have been occluded. Leary and Wearn4 further believe that under such conditions the only source of blood supply to the myocardium is through these channels.
Although several instances of occlusion of both coronary arteries have been reported5 in which a thebesian circulation was assumed, in no such case, so far as we know, have the sinusoids or dilated thebesian channels been investigated histologically and their distribution and other features studied. The heart of a boy, aged 16, described in case 5 in a paper on "Tuberculosis of the Myocardium,"6 presented a certain combination of pathologic changes which make it appear that for a