“…This results in the irradiation of a narrow zone around the (Corscaden and Tovell, 1954;Rickford, 1954;Miller et al, 1962;Allen and Fraleigh, 1963 ;Gusberg and Yannopoulos, 1964;Hawksworth, 1964;Renning and Javert, 1964;Dobbie et al, 1965;Beck, 1967;Carmichael and Bean, 1967;Roman et al, 1967;Brown et al, 1968;Hirabayashi and Graham, 1968). This results in the irradiation of a narrow zone around the (Corscaden and Tovell, 1954;Rickford, 1954;Miller et al, 1962;Allen and Fraleigh, 1963 ;Gusberg and Yannopoulos, 1964;Hawksworth, 1964;Renning and Javert, 1964;Dobbie et al, 1965;Beck, 1967;Carmichael and Bean, 1967;Roman et al, 1967;Brown et al, 1968;Hirabayashi and Graham, 1968).…”