Certain tiny formations of the lip vessels called "microcherry," "glomerulus," and "venous lake" have been studied in 427 patients. Among the 427 there were 101 patients who had peptic ulcer or a history of ulcer. The studies indicate that these vascular formations increased with age and are more common in males than in females. Patients with ulcer, however, showed vascular formations earlier in life and in greater number than did controls without ulcer. These observations suggest that vascular formations are correlated with the ulcer diathesis. This lends support to the hypothesis that a vascular substrate which is derived genetically or environmentally, or both, predisposes the individual to gastroduodenal ulcer.