“…The first two-dimensional ultrasonic scans were obtained by Howry and Bliss (1952) and Wild and Reid (1952 a, b). T h e method is nowadays used in many fields, which include obstetrics and gynaecology Brown 1961, Donald andAbdulla 1967, andfigure 18), and the diagnosis of diseases of the breast (Hayashi et al 1962, Wells and, the liver (Howry 1965, McCarthy et al 1967, the eye (Baum and Greenwood 1965) and the kidney (Damascelli et al 1968). Most investigations involve the making of several scans, often in two groups of parallel sections, one group being planes at right angles to those in the other group.…”