In New Zealand rabbits pulses of pressure (seventy millimeters of mercury at two-second intervals) applied by a pneumatic tourniquet placed about the leg and connected to an animal respirator consistently increased femoral nutrient vein blood flow 16 to 150 per cent when the pulses were superimposed on an ambient pressure of five millimeters of mercury, while the same pulses superimposed on an ambient pressure of twenty millimeters of mercury consistently reduced blood flow 25 to 59 per cent.