These observations were made with the object of determining whether the vitally staining reticulation of young erythrocytes persists or is lost in blood preserved in vitro. In this manner it was hoped to gain some further information concerning the effect of such preservation on the erythrocyte from the point of view of the value of such cells for transfusion purposes. If it could be shown that preservation of erythrocytes in vitro for several weeks or a month did not reduce the percentage of cells in which the reticulation could be demonstrated by vital staining it might, perhaps, be assumed that the preserved erythrocytes had not aged during the period of preservation and were from this point of view as suitable for transfusion as freshly drawn cells.
Rous and Turner1 obtained the best preservation of human erythrocytes with three parts of blood in two parts of isotonic (3.8 per cent.) sodium