In a series of 235 autopsies, changes in the subcapsular thoracic fascia similar to elastofibroma dorsi (Järvi&Saxén1959,‐et al.1969) were found in 39 cases, all at least 58 years old. In people over 55 years, the frequency was 24.4 per cent in females and 11.2 per cent in males. In addition to hypertrophy and secondary degeneration of elastic fibres, necrosis of collagenous‐, adipose‐, muscular‐, and nervous tissue, as well as formation of clefts, cysts and bursae was found in 85 per cent of cases presenting elastic changes—both in connection with them and outside the degenerated areas—as well as in 39 per cent of cases where no elastic degeneration occurred. Other changes included extensive scarring of the tissue, followed by reduction of fat and, more seldom, oedema and inflammatory infiltration. Breaks in the elastic cage, necrosis and fibrosis of arterial walls were found in 44 per cent of cases of elastic degeneration and in 14 per cent of cases without degeneration. In veins, more extensive wall fibrosis occurred, leading to necrosis; in cases of elastic degeneration the adventitial elastic network was also involved. Venous changes were found in 90 per cent of the cases of elastic degeneration and in 30 per cent of cases without degeneration. Direct mechanical stress on elastic tissue may be an important cause of hypertrophy and secondary degeneration of elastic fibres, and also of diffuse increase of collagenous tissue. On the other hand, nutritional deficiency due to failing resistance of the vascular system against friction of the scapula and streching movements of the upper extremities may play a main part in necrotic t