So this is the side of the mother. This is the side of the fetus. So what happens is carbon dioxide moves down its concentration gradient from this side from the fetus's side to the mother's side. Now, as it moves this way, what happens is the concentration of the carbon, the oxide, begins to increase within the side of the mother. And by increasing the CO2 concentration, that makes the hemoglobin much more likely to actually release the oxygen. And once oxygen is released, we have the bore effect.