1. Experimental evidence has been presented showing that crystalbumin (the carbohydrate-poor fraction of serum albumin) is the factor which prevents mammalian red blood cells from becoming spherical at pH values over 9.2.

2. The amount of crystalbumin taken up from a solution of it by red cells previously freed of it is of the order of 800 mg. per 100 c.c. of red cells. If this amount is all taken up at the red cell surface, it would form a layer only a few molecules thick.

3. The electrophoretic mobility in phosphate buffer of pH 7.4 is the same for cells containing crystalbumin, cells free of crystalbumin, cells with anti-sphering activity counteracted by fatty acid, and ghosts which have been temporarily sphered by a rise in pH. The mobilities in a saline-glycine buffer solution of pH 10.1 for the first three classes of cells just mentioned are also the same. The mobility of cells sphered with lecithin in a saline-phosphate buffer solution is the same as that for untreated discoidal cells.

John D. Jones Scholar at the Biological Laboratory, 1939.