1. The anteroposterior view and the lateral view made with the patient in the "frog-leg" position are not a complete examination of the hip joint.
2. Horizontal lateral roentgenograms of the hip in children, in conjunction with other views, offer a more comprehensive method of investigation in the diagnosis and treatment of pathological conditions of the hip.
3. While no statistically valid data may be drawn from the present small volume of work, interesting observations have been made in roentgenography of congenital dislocation of the hip, Legg-Perthes disease, and slipped capital femoral epiphysis.