1. Guinea pigs die shortly after bilateral cervical vagotomy, even when continuous artificial respiration effected through a tracheal cannula is carried out. Death is caused by severe pulmonary edema and congestion.
2. Direct observation of the lungs after bilateral vagotomy demonstrates that pulmonary edema develops gradually and increases slowly in amount and severity. Congestion precedes and accompanies the development of the edema.
3. Neuropathic pulmonary edema in the guinea pig is caused by disturbance to or abolition of the pulmonary vasomotor nerves.
4. The evidence obtained by experiments on animals suggests that neuropathic pulmonary edema in man is caused by disturbances, either central or peripheral, to the vasomotor control of the pulmonary vessels.