The skin in this region is thick, and possesses a considerable subcutaneous tissue, in which lipomata not infrequently develop, and which occasionally shift their position under gravity to perhaps the front of the chest. The deltoid muscle in its sheath covers in the whole region. Under the deltoid is a quantity of loose connective tissue, which may occasionally be membranous, and exert an effect in limiting abscesses of the joint. In this loose tissue are one or more bursee, which separate the muscles from the underlying structures. The coracoid process gives attachment by its inner border to the pectoralis minor, and by its apex to the coraco-brachialis and short head of the biceps. It gives attachment to the coraco-clavicular ligaments (conoid and trapezoid) by its upper surface, and by its outer border to the coraco-acromial ligament, which is a flat band, triangular in outline, uniting the acromion and coracoid, and thus completing the cor aco-acromi al arch. This arch overhangs and completes the shoulder-joint, from which it is separated by the subacromial bursa, which lies between the arch and the capsule with tendons of the capsular muscles. This bursa is frequently the seat of disease, rendering abduction movements painful. When it suppurates, the pus may burst into the loose subdeltoid areolar tissue, and simulate disease of the shoulder-joint. As the fascia covering in the deltoid and infraspinati muscles posteriorly is dense, the pus generally presents anteriorly.' It may be torn by twists of the arm, and sometimes communicates with the joint in old people.