“…Some of those used in the literature have been: a fall in the hemoglobin level to 7 grams per 100 cc. or less, the necessity of five or more blood transfusions during the period of hospitalization, a total circulating red cell mass of less than 60 per cent of normal, or a fall in the red blood count to 3 million or less (1, 2, 4, 5 and 6).…”