INTEREST tends to be lost in the fundamental science of anatomy in this surgical decade of wider excision and physicochemical problems. This subject is anatomical. It is the result of several years of clinical observation supported by the written reports of other authors. THE PROBLEM In a recent report Woodhall 12 warns against accidental division of the spinal accessory nerve during minor operations in the posterior triangle of the neck. Such a mishap results in a paralysis of the trapezius muscle. In the upper neck, incision and dissection for protean entities frequently results in a paralysis of the corner of the mouth, or the depressor anguli oris muscle, on the side of operation. Division of the marginal mandibular branch of the facial nerve is the cause of this bothersome cosmetic deformity (Fig. 1). It may occur after removal of a lymph node or a simple branchiogenic cyst. The significance of