Acculturation and assimilation of persons of L Mexican origin in the Southwest has been slowed by various social mechanisms of the larger society which tend to keep these people separate, and by a tendency on their part to separate themselves from the larger community by living inbarrios. One result of this sociocultural isolation is the preservation of many folk beliefs of Spanish and Hispanic-American origins. Most important among these from a medical point of view are the prescientific concepts of health and disease and the related practices. Prominent among the disease concepts aremal ojo(evil eye),empacho(surfeit),susto(magical fright),caída de mollera(fallen fontanelle), andmal puesto(hex). Gillin1gives a detailed account ofsustoin Guatemalan natives and draws parallels between folk and scientific (psychiatric) therapeutics. The existence of the first three concepts among Spanish-speaking Americans has been described by Saunders.2Clark's work