Organ homotransplantation, without saintly intervention, has had to wait until just a few years ago for similar success. At the end of the eighteenth century, John Hunter transplanted teeth from one person to another with success, and also demonstrated that a human tooth could be transplanted to a cock's comb, teeth apparently being relatively inert antigenically. In the early twentieth century, Alexis Carrel, the pioneer of the vascular suture, carried out renal transplantations in dogs. He was clearly aware that although he could overcome the technical surgical problems, he was defeated by the biology of transplantation. By 1961, at least twenty-five more renal transplantations had taken place between human identical twins; of these, the Boston team performed seventeen. Three of their patients died, one from thrombosis of the renal vessels and two from glomerulonephritis of the transplant in patients who had suffered from it before surgery.