1. In the hypertension which accompanies constriction of the renal arteries, there is no constant relationship between the height of the general systemic arterial pressure and the pressure in the renal artery distal to the point of constriction. The hypertension may persist even though the renal arterial pressure returns to or almost to the control level.
2. Studies on the renal blood flow and oxygen consumption following subtotal nephrectomy were abandoned because of inability to produce hypertension in dogs by this method. It is suggested that the mechanism of the hypertension following renal arterial constriction (dogs) and that following subtotal nephrectomy (rats) may not be the same in the two instances.
3. Studies on isolated renal cortical tissue of dogs and of rabbits following renal arterial constriction and subtotal nephrectomy showed that there is not necessarily a diminution in the capacity of the tissues of hypertensive animals to use oxygen.