2.Fluid was collected from the orifice in the vestibule and examined by the laboratory. The latter reported the fluid to be " urine but very dilute," the urea content being 0.63 per cent.3 . The bladder was filled with methylene blue solution. The fluid from the orifice was collected and found to be entirely colourless.4 Methylene blue solution ( 2 0 nil.) injected intravenously resulted in the fluid from the orifice being faintly tinged with blue, but the concentration was much less than that foimd in the urine from the bladder.It was therefore assumed that the track, of which the orifice was the lower end, did not communicate with the bladder, but did communicate with some poorly functioning renal tissue. 5. Intravenous pyelography was aext performed and this showed normal urinary tracts on both sides with the exception that the pelvis and calyces of the left kidney showed slight dilatation.This showed no abnormality of the bladder. Both ureteric orifices and the urethral orifice were normally positioned.Retrograde catheterization showed normal urine coming from each ureter and retrograde pyelography revealed no abnormalitv of the urinary tracts except for the mild dilatation of the left kidney pelvis and calyces alreadv mentioned (Fig. 2) 7 . The next procedure carried out was injection of Pyelosil through the orifice in the vestibule. This proved to be difficult owing to the tiny orifice and backward leakage of the Pyelosil. Finally, success was obtained, using a Hamilton Bailey intravenous needle and record syringe. The patient was then' screened and X-rayed. The outline of the track w a s then clearlv \-isible. It 6 . Cpstoscopy was performed.