On the Anatomy, Physiology, and Pathology of the Chimpanzee

of the Head, Neck, and Back, The plactysmo myoides (text-fig. 25) is much thicker than in Man. It arises from the fascia over the pectoralis m:tjor and deltoid, and the two muscles are inseparable in the middle line of the neck. I t s lateral parts are more muscnlm and thicker than the medial portions. About an inch below the symphysis menti the fibres of the mesial parts decussate (Ruge 42, Uhampneys ll), and I observed the fibres of the left muscle lying superficial to those of the right one ; but Quain describes the reverse Text-figure 25.