The first question that presents itself to the surgeon when operating for appendicitis is that as to how and where he had best make his incision. The main point by which he is guided in deciding this is the nature of the case under consideration; that is, whether it be an acute or an interval case. In interval cases every surgeon nowadays tries to get through with as small an incision as possible and arranges his work in such a way that there will remain no tendency nor possibility of the appearance of a ventral hernia. Thus he traverses the external oblique and transversalis muscles near the anterior superior spine, bluntly, according to the direction of their fibers— McBurney's gridiron incision 1 ; or he makes the cut at the outer border of the right rectus muscle, then displaces it inwardly in order to reach a spot of its posterior sheath