The large number of operations on the phrenic nerve performed in recent years has stimulated interest in the relative effect of contraction of the diaphragm on the upper and lower lobes of the lung. Paralysis of the diaphragm by section of the phrenic nerve was first advised for disease of the lower lobe, but more recently it has been advocated for involvement of the upper lobe also. The question as to which lobe under similar conditions is more benefited by paralysis of the diaphragm is still unsettled. Some surgeons report more favorable results on lesions of the lower lobe; others believe that the upper and lower lobes are equally benefited. With that issue in view, these experiments were carried out.
No method has been devised by which the respired air from an individual pulmonary lobe can be measured satisfactorily, but one would expect the changes in the bronchial