TO THE EDITOR: the criticism by Dr. Brengelmann (1) of my

emphasis on the key importance of the elastic recoil pressure of the venous structures must seem to some to be just like the circulation—it keeps going around and around! I have no disagreement with Dr. Brengelmann that the energy from the heart plays a key role in the circulation, but it does not determine the maximum flow and it is not necessary even for the maximum flow to occur. In contrast to Brengelmann’s statement that “none of the energy dissipated in forcing Q through Rvs comes from the elastic recoil of venous compart-ments, ” essentially all of the energy is due to recoil force at the moment of removing the heart. A pressure exists in the vas-culature that is due to the force generated by all the volume in the system and the sum of the elastances of all the compart-ments even without flow. If the heart is stopped and instanta-neously removed from the body so that the great veins empt