Lesions by bullets, arrows, stabs, bruises and lacerations in parturition, treads, wheels, tumors, ulcers, calculi, tubercles, parasites. Course. Pathology: transverse division may cause hydronephrosis, or septic peritonitis. Symptoms: uncertain, traumatism, bloody urine, arched, stiff, tender loins, straining, recumbency, groaning in turning or rising, rectal palpation of distended ureter, of ascitic fluid, pitting on pressure of loin, flank or groin, liquid drawn through a cannula is urinous, urine still discharged by normal channel. Crystals in urine, worm ova. Treatment: compresses, fomentations, sinapisms, anodynes, balsams, antispasmodics, extraction of calculus, lateral implantation of urethra. From their deep and protected position it might be plausibly concluded that the ureters were secure against every kind of traumatism. This however, is not the case, since in both man and animals they have been known to have been injured by bullet wounds, arrow wounds, and stab wounds of various kinds. In dystokia with laceration of the womb, vagina or bladder the ureter is liable to be injured. By blows and kicks it may even be ruptured or torn across, and also by sudden and severe mechanical compression of the abdomen as when run over by a wagon or trodden on by a horse, ox, or other large animal. Tumors of various kinds may grow in, or press upon the ureter, ulcers with thick indurated margins or base may obstruct the passage, or calculi, or worms may block and give rise to overdistension and even rupture. Kopp describes obstruction by multiple calculi with saccular dilation in front, close to the kidney in a cow. Cadiot records cases of thickening of the mucosa by numerous cysts as small as hempseed. Intra-abdominal tumors of the spermatic cord have been known to block the passage. Again tubercles have formed on the urethra, and polypi on the trigonum vesicæ have blocked the ureter and produced all the evil consequences of calculus, parasites, etc. _Course._ The progress of the disease will vary greatly according to the nature of the lesion. With complete rupture of the ureter the urine as a rule escapes into the peritoneal cavity. If the urine is aseptic this may not lead to serious results and the edges of the wound cicatrizing, the urine is imprisoned in the ureter and pelvis of the kidney, and leads to final atrophy of the kidney and hydronephrosis. When on the other hand infecting matter escapes with the urine, as in perforating ulcer, tubercle, glanders, cancer, infective catarrh of the kidneys or ureter, such infection is brought in contact with the whole peritoneal surface, where secondary infections follow. In cases associated with penetrating wounds, wounds resulting from dystokia, calculus or parasitic obstruction, similar infection is to be dreaded.