IN HIS papers of 1929 and 1937, Hörniker1stressed that the terminal macular vessels are easily injured by disturbances, especially of an angioneurotic (angiospastic) kind. The case of spasm of the macular arteries reported here presented a different picture from that of many macular disturbances attributed by Hörniker to spasm of the terminal vessels, but the analogy is clear. The case was one of obstruction which within a few days affected nearly all the macular arteries, including the cilioretinal artery. I had the opportunity of treating the patient for more than a year. In the beginning, I examined him daily; later, examinations were made at longer intervals. During the daily examinations of the fundus, I saw interesting changes in the affected vessels which seemed to me worthy of record. REPORT OF CASE History. —O. H. T., a Chinese aged 34, presented himself on Aug. 25, 1944, with the complaint