markable skill in injecting fine blood-vessels. His most celebrated work is the monograph on epithelial cancer, in which he first determined with precision the origin of malignant tumors, and at the same time drew the most important practical conclusions from an essentially embryological idea. His excellent treatises on the healing of wounds and on transplantation of the skin are no less based on theoretical preliminary study. The certainty of his surgical methods was with Thiersch the result of his anatomical and pathological knowledge. In a thoughtful obituary notice, Professor Landerer, one of his former pupils, writes: "Thiersch's operating was the direct outcome of applied and pathological anatomy. With his phenomenal knowledge of these departments he could allow himself to build up his plan of operation directly on the diagnosis, and always to proceed as a free, creative worker."
Thiersch is reported to have said of himself that he was really an anatomist gone astray. In the interest of suffering humanity, however, it was surely well that he turned from anatomy to surgery, for he was a surgeon by the grace of God. He possessed not only the necessary firmness of eye and hand, but also a sovereign calmness that even in the most trying situations never failed him. Above all, the most beautiful quality that a great physician can have was his: he was possesssed of delicate sensibilities, and was thoroughly humane in his disposition. This last quality was perhaps the most prominent of Thiersch's many virtues, yet it was the one he endeavored most carefully to conceal. He burdened his heart with every one of his seriously sick patients; in critical cases he hurried to the hospital at the most unusual times, and if, contrary to his expectations, a serious operation resulted unsuccessfully, it was often days, and even weeks, as Landerer tells us, before he could reconcile himself to the result. He would criticise himself severely in order to determine whether he had not some mistake or neglect with which to reproach himself.
Thiersch's favorite resort was the children's wards. There he could devote himself to each without reserve. He remembered each of his little patients, and when, after their leaving the hospital, he occasionally met them in the street, he used to speak with them and inquire after their health. And for this the "Herr Geheimrath" was deeply revered by all who had been his patients, and it was a festival for them when his birthday or some other occasion gave them an opportunity of showing their affection by some little attention.
I should overstep the limits of an academic discourse if I followed further the tender side of Thiersch's personality. Yet one thing I must not pass over: that is, the beneficent influence of his humanity
