As soon as the surgeon clearly establishes the existence of a ureteral fistula he is beset with the necessity of deciding which duct is the seat of damage. Some years ago, when it was the practice to remove the kidney for a persistent ureteral fistula, the decision involved the surgeon in a grave responsibility, for the removal of the wrong kidney could only be regarded as a catastrophe for the patient. Morris has recorded a case in which this actually happened. A woman had total hysterectomy performed for a cervix fibroid by a gynæcologist; in the course of the convalescence a ureteral fistula was recognized, and as this failed to close spontaneously, a surgical colleague performed nephrectomy, and next day found to his chagrin that he had removed the kidney belonging to the uninjured ureter. Serious accidents of this kind are less likely to happen now, because the surgeon can avail himself of the cystoscope and ureteral catheter; with these instruments it is possible, not only to decide with certainty which ureter is injured, but also to determine the position and extent of the damage. See also Vol. III. It is important to remember that every ureteral fistula does not require an operation. It is always advisable, when it has been clearly established that a woman has a leaking ureter, to wait a little, certainly six weeks, for many fistulæ of this kind will gradually close. In describing such a case, Jonas draws attention to a cystoscopic sign of some value. He performed a total hysterectomy for fibroids, and on the tenth day the nurse reported the escape of urine by the vagina. The daily output of urine from the bladder, which had averaged 50 ounces, fell to 25 ounces. On cystoscopic examination, urine could be seen issuing from the right ureteral orifice; at first the left orifice could not be seen, but on careful watching a movement was detected similar to the contraction of a ureter discharging urine, but no fluid came from the opening. This is known as _leergehen_ (empty contraction), and it indicates that there is a lateral opening, but not complete interruption in the continuity of the ureter. Such a case should have an opportunity of healing spontaneously. This happened in Jonas’s patient.