“…In Cambridge we found 84 %/O, in Boston there were 86 % (Craighead, 1969), in Washington 81 % (Rowe et al 1956) and in Bristol there were 86 % (Caul et al 1971). When younger patients are included in the groups the total is again similar -Cambridge 66 %, Boston 65 %, Bristol 64 %, in blood donors in Rumania 64 % (Diosi, Moldovan & Tomescu, 1969) and in Finland 66 % (Klemola, von Essen, Paloheimo & Furuhjelm, 1969).…”