H. J. Meiselman From the theoretical studies of Dr. Skalak, it is clear that white cells can significantly influence the pressure-time profile of a red cell/white cell suspen sion, and that the presence of even a small amount of relatively rigid white cells can have a profound effect on the filtration pressure during the latter portion of a filtration experiment. Conversely, white cell effects, regardless of their relative rigidity, are shown to have only minimal effects during the very early (i. e., 0-2 seconds) phases of the filtration process. Dr. Chien's experimental data support these...