When Simon, in 1869, removed by lumbar incision the. kidney of a woman who had a ureteral fistula opening on the abdominal wall above the pubes, he succeeded not only in proving clearly the erroneousness of Lawrence's contention, that "the kidney, fortunately, was beyond the reach of the surgeon," but also in demonstrating the vital fact that a single kidney is, in many instances at least, capable of performing the duties of itself and mate. Simon's researches created a surgery of the kidney.Previous to 1878 traumatic rupture of the kidney was regarded of very rare occurrence; Maas could find only 71 cases recorded in the literature. To-day, owing to the advent of the many methods of rapid transit, combined with the increased number of dangerous occupations followed by mankind, the kidney is more frequently ruptured than in former years. Ninety-four per cent. of the patients are males.