Variation in hair histological variables: medulla and diameter

Two hair histological variables, the incidence of medullation and diameter, have been dealth with in twelve populations belonging to different ethnic groups and living in different geographical areas. Results of the F test comparing within-individual variance, between-individual variance and between-population variance of the hair variables concerned indicate that differentiation of various populations is possible. Sex differences for medulla and diameter of hair are observed in some populations included in the present study.