These are, in general, of little importance. The ureter may be double either in its whole course or in its upper part. The pelvis may also be double or in several divisions, each of which has a separate connection with the ureter. The ureter may arise from the pelvis at an acute angle, or there may be a kind of valve in the course of the ureter from a fold of mucous membrane?
Rayer, Traite des malad. des reins, iii.; FOrster, Die Missbil-dungen; Lancereaux, L'Union med., 1880; Landau, Die Wanderniere d. Frauen, 1882; Report of Committee, Path, trans., xxvii., 1876; Newman, Surgical dis. of kidney, 1888; Bostrom, Path. Anat. der Niere, 1886.