In the period of 1957-1964, 6633 subjects were examined twice by Hall's method, including 5604 children and adolescents at the age of 0-18 years which makes up. 1.72% of the population. The number of examined boys was 2844 (1.71% of population), that of girls 2760 (1.72% of population). The data are given in Tables I and II. A correlation was found to exist between the incidence of enterobiosis, age, social and living conditions of examined groups, regardless of urban or rural environment. Sex does not seem to play an essential role. The comparison of the present studies with those of other Polish authors was not invariably feasible as the latter varied as regards the methods and material used and did not contain any mention that demographic data had been taken in consideration in individual age groups. The comparable investigations are given in Table III. The advisability of mass epidemiologic studies by Graham's methods is discussed. In order to obtain comparable results, standarization of methods and selection of material is proposed in mass investigations on the incidence of parasites of the alimentary tract
