THE CLINICAL application of lung transplantation awaits the resolution of the immunological mechanism responsible for homograft rejection. Lung transplantation in the dog has become feasible as a result of resolution of technical difficulties.1,2In order to study homotransplantation intelligently it would appear necessary to develop techniques for autotransplantation (reimplantation). One is immediately impressed with the dearth of reports in the literature concerning reimplantation of an entire lung in the experimental animal with longterm survival. Borrie3has been working with sheep for years and has not yet been able to obtain a long-term survivor with a functional reimplanted lung. In 1951 Juvenelle et al.4reported the first successful reimplantation; on sacrifice 35 months later this animal had a functioning lung. Neptune et al.1in 1953 described a one-year survivor of lung reimplantation with normal function as determined by bronchospirometry. In 1959 we obtained a successful reimplantation which