If the tumour or ulcer is small, and involves a considerable thickness of the lip, it is most easily removed by a V-shaped incision (Fig. XIX. A B A). Its shape permits the most accurate apposition of the cut surfaces; and if the lips are full and the tumour small, very slight trace of the operation will remain. [Illustration: FIG. XIX.[99]] Again, if the tumour be more extensive, involving a large portion of the prolabium, and yet not extending deeply into the substance of the lip, it may be very easily removed by a pair of curved scissors, applied in the direction shown in the diagram (Fig. XX. A B). The skin must then be stitched to the mucous membrane by numerous points of interrupted suture. [Illustration: FIG. XX.[100]] But if the tumour be at once extensive and deep, mere removal is not sufficient, but some provision must be made for supplying the blank left by the operation. In cases where a third, or even a half, of the lower lip has thus been removed, it may be found sufficient freely to dissect what is left of the lip from the gums, and thus approximate the cut surfaces in the middle line. This alone, however, would so much diminish the buccal orifice, and twist its corners, as to cause great deformity. The addition of an incision horizontally outwards, at one or both angles of the mouth, will do away with such risk, and allow the surfaces to come together without puckering; while by stitching the skin and mucous membrane together in the course of these horizontal incisions, we can increase the size of the buccal orifice almost _ad libitum_. Lastly, when the lower lip has been entirely removed, it is still possible to supply its place in the following manner, which was devised by Mr. Syme: The tumour being fairly isolated by a V-shaped incision (Fig. XXI.) C A C including the whole thickness of the lip, each of the incisions should be prolonged downwards and outwards, as shown by the dotted lines A D, A D. The flaps thus marked out must be separated from the bone, brought upwards, and approximated in the middle line. Possibly it may be necessary still further to enlarge the buccal orifice by short lateral incisions, C C. Whether these are required or not, silk stitches are to be introduced to unite the skin and mucous membrane along the lines A C. The gap left between D B D must be left to granulate, but in most cases may be very much diminished in size by additional sutures at its outer corners, near D. The granulating surface E E very rapidly heals up, leaving a dimple on each side, which rather improves the appearance, by adding to the prominence of the chin, B. [Illustration: FIG. XXI.[101]] [Illustration: FIG. XXII.[102]] THE OPERATIONS FOR HARELIP, though all conducted on the same general principles, vary considerably in extent required according to the position and size of the fissure or fissures to be remedied.