=Treatment.= The only treatment consists in surgical intervention. Some practitioners have recommended giving large doses of purgatives with the idea of causing changes in the neighbourhood of the invaginated part; but such treatment presents little chance of success. The same is true of the administration of large doses of olive oil, either in the form of draught or of enema. Siebert attempted reduction by generating CO_{2} from soda bicarbonate dissolved in water and diluted HCl, injected successively per rectum. In time fæces and CO_{2} escaped, and the patient recovered. Siebert claims to have cured by this method a cow with invagination of five days’ duration; but the effect of his treatment may be doubted, as afterwards a portion of bowel was found in the cow’s dung. When diagnosis is certain, the only treatment that can be recommended consists in performing laparotomy followed by enterotomy. One cannot, however, operate in all cases, nor do all cases offer the same chances of success. If the invagination is situated in the first portion of the small intestine, and is hidden beneath the circle of the hypochondrium, intervention is out of the question, but if it has been detected by rectal exploration in the last portion of the intestine, operation may prove successful. Only in cases of the latter description should it be attempted. Laparotomy is performed in the right flank according to the usual method (see Möller and Dollar’s “Regional Surgery,” p. 313). After opening the peritoneal cavity, the invaginated loop of intestine must be sought. It is not always easy to discover amongst the mass of intestines present, but can be recognised by its hardness and by the congestion of neighbouring parts. After withdrawing it through the abdominal opening, the operator may then proceed by one of several methods. (1.) Some authors recommend grasping the two ends, drawing them apart, and thus reducing the invagination. The actual manœuvre is not difficult, but even when unattended by accident or tearing of the intestine it is by no means always followed by recovery. Although the intestine may not appear gangrenous externally, necrosis often occurs eventually. This method should only be practised during the first twenty-four hours after the appearance of colic, and even then one must always bear in mind the possible consequences just mentioned, and the chances of rapidly fatal septic peritonitis.