1, Trapezius, cervical portion; 2, trapezius, dorsal portion; 3, superior outline of the scapula; 4, spine of the scapula; 5, latissimus dorsi muscle; 6, small posterior serratus; 7, spinal muscles, or common muscular mass; 8, ribs; 9, serratus magnus; 10, external oblique; 11, pectoralis major (sterno-humeral); 12, pectoralis minor (sterno-trochinian); 13, atlas; 14, parotid gland; 15, mastoido-humeralis; 16, point of the arm; 17, sterno-mastoid, or sterno-maxillary; 18, jugular groove; 19, infrahyoid muscles; 20, omo-trachelian muscle; 21, rhomboid; 22, splenius; 23, levator anguli scapulæ; 24, deltoid; 25, supraspinatus; 26, terminal part of the sterno-prescapular, a portion of the small pectoral muscle; 27, brachialis anticus; 28, triceps cubiti, middle or long head; 29, triceps cubiti, external head; 30, olecranon; 31, radial extensor (anterior extensor of the metacarpus); 32, anterior iliac spine; 33, anterior portion of the gluteus maximus--the aponeurosis of the muscle has been divided in order to expose the gluteus medius; 34, posterior portion of the gluteus maximus; 35, gluteus medius; 36, biceps cruris; 37, semitendinosus; 38, point of the buttock; 39, gastrocnemius; 40, tensor of the fascia lata; 41, triceps cruris; 42, ischio-coccygeal muscle; 43, superior sacro-coccygeal; 44, lateral sacro-coccygeal; 45, inferior sacro-coccygeal.] Its origins are similar to those which we have already described in the human rhomboid. It arises from the cervical ligament and the spinous processes of the foremost dorsal vertebræ; its fibres converge and pass to the scapula, to be inserted into its superior or spinal border, or into the internal surface of the cartilage of prolongation. It assists in keeping the scapula applied to the thoracic cage, and when it contracts, draws the scapula upwards and forwards. Taking its fixed point at the scapula, it acts on the neck by its anterior fibres, and extends it. We shall soon have occasion to mention this muscle again, in connection with the study of the muscles of the neck. =The Cutaneous Muscle of the Trunk= (Fig. 71).--Immediately beneath the skin which covers the neck, shoulders, and trunk is found a vast cutaneous muscle, analogous to that which, in the human species, exists only in the cervical region. This thin muscle, whose function is to move the skin which strongly adheres to it, and in this way to remove from it material causes of irritation (insects, for example), is of considerable thickness in the region of the trunk; where it constitutes what certain authors have designated by the name of _panniculus carnosus_. In this region it extends from the posterior border of the shoulder to the thigh, and, in the vertical direction, from the apices of the spinous process of the dorso-lumbar vertebræ to the median line of the abdomen.