In employing any surgical procedure in the treatment of pulmonary tuberculosis, the main purpose is to allow enough collapse of the lung to cause closure of cavities when they exist, and to give sufficient rest to the lesion to insure its healing. To evaluate correctly the results of operations on the phrenic nerve for this purpose, therefore, it must be borne in mind that, while these operations are the least burdensome to the patient, they allow the least collapse and add the least amount of rest to the lesion of any surgical measures at our command. There can be no question that, if it seems probable that the collapse and added rest afforded by phrenicectomy will be sufficient in a given lesion to cause an arrest of the disease, this procedure is preferable to any other. Because of limitations of the procedure, however, extensive fibrotic lesions with cavitation or rapidly