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IT is known that in anaemia the oxygen dissociation curve of the blood is shifted to the right (Richards and Strauss, 1927). This was regarded by as a possible compensatory mechanism of the anaemic state. Although the shift observed by Richards and Strauss was at the abnormal plasma pH of 7.64, a similar shift of the oxygen dissociation curve to the right at the standard plasma pH of 7.4 was later reported by Dill and co-workers (1928) and by Isac, Matthes and Yamanaka (1938). Until now, a satisfactory explanation of this phcnomenon has been lacking. The shift was attributed by Dill and colleagues to the relative acidity of red cells in anaemia, which had previously been directly measured by Hampson and Maizels (1927). In a study of the oxygen dissociation curve in various human anaemias, Kennedy and Valtis (1954) found that the curve, even after correction to standard cell pH, remained shifted to the right. The only exception to this rule was the blood of patients with spherocytic anaemias in which the curve was normal in position after correction to standard cell pH. Kennedy and Valtis suspected that this difference was due to the greater thickness of the spherocytic red cells. The object of the present study was to observe the effect of alterations in red-cell shape on the blood oxygen dissociation curve and, by animal experiments, to isolate this effect from the unknown effects of anaemia. MATERIAL AND METHODSAll the observations were made on the blood of adult male guinea-pigs. Thirteen animals were used for the preliminary study of the oxygen dissociation curve of normal guinea-pigs. Spherocytosis of red cells without anaemia was produced in five animals by the intraperitoneal injection of anti-guinea-pig red-cell serum prepared in rabbits by a modification of the method of Dameshek, Schwartz and Gross (1938). Red cells thinner than normal were obtaincd from nine guinea-pigs splenectomized 2 to 3 months before. In addition, anaemias of various kinds were induced in other groups of guinea-pigs. In four animals an acute posthaemorrhagic anaemia was produced by repeated withdrawal of blood by sterile cardiac puncture; three animals were rendered anaemic by chronic lead poisoning; and in fivc animals larger doses of immune serum than had been used to produce spherocytosis alone were used to produce spherocytosis with anaemia.

BODY WEIGHT AFTER GASTRECTOMY MED] previously were much over standard weight. Different patterns of post-operative weight loss are discussed. Defective fat absorption follows gastrectomy, but the significance of this alone in relation to body weight is doubtful. Both dietary calorie intake and fat absorption are related to body weight, and failure to gain is greatest when both are impaired.When loss of weight follows operation it occurs in the first few post-operative weeks, and thereafter the patient cannot regaln it. The literature upon dietary requirements after severe weight loss and that dealing with the catabolic phase after injury or operation are reviewed.Early post-operative drip feeding of a high-calorie high-protein mixture can prevent the loss of weight in the early post-operative period.