LOUIS TOBIAN There are many reasons for suspecting that the medulla of the kidney is involved in the pathogenesis of hypertension. Although our present knowledge does not permit the assignment of a precise and exact role for the medulla, there are so many indications of its involvement that this is an appropriate time for the subject to be thoroughly reviewed, as Drs. MandaI and Bohman have done in this volume. The involvement of the renal medulla in hypertension was first strongly indicated by the studies of Eric Muirhead. Studying renoprival hyperten sion, he demonstrated that the injection...