IN RECENT years there has been an increased interest in resection of segments of the bronchopulmonary tree. Frequently the proximity of lesions to the tracheal bifurcation makes resection impossible. Removal of the tracheal bifurcation and regional lymph nodes would necessitate the development of reconstructive procedures, in particular, anastomoses between the trachea and major bronchial divisions. If functioning anastomoses could be made without overwhelming risk, resections of this magnitude could be carried out. Such a surgical procedure might well extend the limits of resectability in dealing with lesions at or near the carina. The experiments herein reported were undertaken to determine the feasibility of performing a bronchotracheal anastomosis and the survival and function of transposed pulmonary tissue. Taffel,1 in 1940, published the results of his experimental work on the repair of tracheal defects in dogs. He created circular defects in the cervical trachea and covered these with fascial grafts. He