“…Heritability of peak flow also appears to be relatively high (Beigel, 1955;Brumby, 1961;Burgkart-Schnepf and Burgkart, 1960;Dodd, 1953;Dodd and Foot, 1953 ;Donald, I960;Jannermann, 1960;Larsen ejb a_l., 1960;Pfeifer, 1957;Politick, 1961 ;Szajko, 1959;Venge, 1961 ;and Wilke, I960). In general, nu tritional levels and other environmental influences which, ac cording to Horny and Hertrampf (I960), exert large effects on peak flow, have not been evaluated specifically in most investi gations reported to date.…”