Unilobar injection of starch solution produced pulmonary infarction at the site of injection and diffuse bilateral pulmonary edema. The predominantly or entirely unilobar distribution of the embolizing material was established by histologic methods and by a technic using whole lung lobe suspension stained with Lugol's solution. Evidence is presented suggesting that the pulmonary edema in the nonembolized lobes is attributable to neural or neurohumoral mechanisms.