HARELIP, a congenital perpendicular fissure or fissures through Ihe upper lip, the i result of an arrest of development, (Eriehsen). It is named from its resemblance to the lip of a hare, but according to Gcoffroy St. Hilaire, it is not analagous to that form of development, but to that which occurs in animals of lower development, viz: fishes. When the arrest of development takes place on one side only, the malformation is called single harelip, and according to Erichsen. it most frequently is located on the left side. When the fissure occurs on each side of the median line the malformation is called double harelip, and the fissure is always deeper on one side than on the other, generally extending into the nostril when it produces cleft palate, the nose being flattened and :xpanded. Median fissure is extremely rare. Delithaye saw a case of the upper lip, Nicati one of lowet lip. The Cure of harelip reqtiires a very careful operation.
There is difference of opinion as to whether the operation ought to be performed before or after dentition, and those who advocate waiting urge that young children are apt to have convulsions from various exciting causes. The weight of authority, however,
appears to be in favor of early operations, which are easier to perform before dentition. The child will also be better able to nurse, after the operation. In operating, it is important to procure direct union of the edges of the fissure, which are carefully pared and held together by silver sutures and straps of plaster, and a check compresser, an ingenious apparatus by which pressure upon the cheeks tends to keep the cut parts in opposition. The application of water-dressing, or a weak solution of carbolic :Mid. is often found serviceable, but need not be constantly applied unless, unfortunately, great inflammation occurs, when feeding will have to he done through a tube; but this is rarely the case.