The following case is reported because it is believed to be the only one of retinoblastoma1known to have occurred in an adult. It is also unusual, however, in regard to the site of origin, the mode of extension, and the abundance of rosets in the growth. As I did not see the patient until after the removal of the eye, the clinical notes on the case are from the hospital records. REPORT OF CASE History.—John W., a white man, aged 48, was admitted to the infirmary, Aug. 27, 1928, in the service of Dr. Derby. He had been married for sixteen years, but had no children living. His wife had one miscarriage. One infant died soon after birth. Three of the patient's sisters were alive and well. His general health was excellent, and he had never had any serious illness. Six months before admission, he noticed spots