(1) This was not an artifact, as those erythrocytes fixed within the blood vessels retained a normal biconcave shape.(2) Under high power unstained red blood cells appear as pale, homogeneous, biconcave discs with no nucleus.(3) The seventh cervical vertebra is biconcave and is well preserved.(4) Genetic defects of the red cell membrane may cause the red cells to assume a spherical rather than a biconcave shape, or alter their configuration to an elliptical form.(5) Ribs are straight or slightly biconcave and fade on the ventral surface where they merge into the lateral keel.
