Abstract 1. 1. A procedure for anastomosis of the pulmonary artery to the left auricle in dogs is described. 2. 2. In the successful experiments, this procedure reproduced the circulatory derangements found in the cyanotic type of congenital heart disease. 3. 3. In one experiment, hypertrophic osteoarthropathy developed, and was apparently attributable to increased systemic blood flow.